I would like to ask some help here. I have a personal car project (mix of track and street use) and would like to build my own dashboard. I know most of people would recommend to use a regular 7-segment display for speedometer . However I want to keep the traditional look of analog speedo with needle style. However the stepper motor offers high precision. I built a simple circuit with BX24 and Swisstec X25 stepper motor and started playing with. It works fine. Now I would like to ask for some help: - any suggestion on which kind of circuit should I use to read the gearbox electronic speedo sensor signal? I know it is a square wave which modulates frequency according the speed. I believe most cars are like this. I don't have any idea on how to connect the speedo signal and process that data. Should I do a frequency-to-voltage converter? Or any other idea? Or should I use just the BX24 to count pulses and make all data processing to convert to the speedo signal information into pulses for the stepper motor? - any suggestion on software code to properly move the stepper motor according the car speed? Should I do some internal register in software so I know exactly where the needle is in the dash? I mean, should I always know where the needle is exactly and how much up/down movement it is necessary as next step? Because I need to control clockwise and counter clockwise movements. Any suggestion on how to proceed with this project? Here is the simple code I did just to test the stepper motor and confirm that basic circuit is working fine.
-----------Option Explicit Public Sub Main() Dim n as integerConst M1 as Byte = 12 'this is the pin to drive Motor Pin1Const M2 as Byte = 11 'this is the pin to drive Motor Pin2=Pin3Const M4 as Byte = 10 'this is the pin to drive Motor Pin4Const POn as Byte = 0 'NOR port working as inverter, so the logic should be inverted.This case "Pulse On=0"Const POff as Byte = 1 'This case "Pulse Off=1" 'simple testing for n = 1 to 50'#1 Call PulseOut(M1, 0.002, POn ) 'M1=1 after NOR (inverter) Call PulseOut(M2, 0.002, POff) 'M2=0 after NOR ( inverter) Call PulseOut(M4, 0.002, POn ) 'M4=1 after NOR ( inverter) '#2 CallPulseOut(M1, 0.002, POn ) 'M1=1 after NOR ( inverter) Call PulseOut(M2,0.002, POff) 'M2=0 after NOR ( inverter) Call PulseOut(M4, 0.002, POff) 'M4=0 after NOR ( inverter) '#3 Call PulseOut(M1, 0.002, POn) 'M1=1 after NOR ( inverter) Call PulseOut(M2, 0.002, POn) 'M2=1after NOR ( = inverter) Call PulseOut(M4, 0.002, POff) 'M4=0 after NOR ( = inverter)'#4 Call PulseOut(M1, 0.002, POff) 'M1=0 after NOR ( = inverter) Call PulseOut(M2, 0.002, POn) 'M2=1 after NOR ( = inverter) Call PulseOut(M4, 0.002, POff) 'M4=0 after NOR ( = inverter)'#5 Call PulseOut(M1, 0.002, POff) 'M1=0 after NOR ( = inverter) Call PulseOut(M2, 0.002, POn) 'M2=1 after NOR ( = inverter) Call PulseOut(M4, 0.002, POn) 'M4=1 after NOR ( = inverter)'#6 Call PulseOut(M1, 0.002, POff) 'M1=0 after NOR ( = inverter) Call PulseOut(M2, 0.002, POff) 'M2=0 after NOR ( = inverter) Call PulseOut(M4, 0.002, POn) 'M4=1 after NOR ( = inverter) Next End Sub ----------- Also the diagram for the stepper motor control circuit. As you can see, there is enough pins available for more implementation.
f/v are nice since it simplifies your programming. Also the LM2917 chip goes to zero with zero input - this saves hassle of dealing with overruns on very slow rotations.
Richard
From: b... [mailto:b...] On Behalf Of ericksoliveira Sent: Sunday, November 21, 2010 8:25 PM To: b... Subject: [BasicX] Help with Speedometer using stepper motor and BX24
I would like to ask some help here. I have a personal car project (mix of track and street use) and would like to build my own dashboard. I know most of people would recommend to use a regular 7-segment display for speedometer . However I want to keep the traditional look of analog speedo with needle style. However the stepper motor offers high precision. I built a simple circuit with BX24 and Swisstec X25 stepper motor and started playing with. It works fine. Now I would like to ask for some help: - any suggestion on which kind of circuit should I use to read the gearbox electronic speedo sensor signal? I know it is a square wave which modulates frequency according the speed. I believe most cars are like this. I don't have any idea on how to connect the speedo signal and process that data. Should I do a frequency-to-voltage converter? Or any other idea? Or should I use just the BX24 to count pulses and make all data processing to convert to the speedo signal information into pulses for the stepper motor? - any suggestion on software code to properly move the stepper motor according the car speed? Should I do some internal register in software so I know exactly where the needle is in the dash? I mean, should I always know where the needle is exactly and how much up/down movement it is necessary as next step? Because I need to control clockwise and counter clockwise movements. Any suggestion on how to proceed with this project? Here is the simple code I did just to test the stepper motor and confirm that basic circuit is working fine.
-----------Option Explicit Public Sub Main() Dim n as integerConst M1 as Byte = 12 'this is the pin to drive Motor Pin1Const M2 as Byte = 11 'this is the pin to drive Motor Pin2=Pin3Const M4 as Byte = 10 'this is the pin to drive Motor Pin4Const POn as Byte = 0 'NOR port working as inverter, so the logic should be inverted.This case "Pulse On=0"Const POff as Byte = 1 'This case "Pulse Off=1" 'simple testing for n = 1 to 50'#1 Call PulseOut(M1, 0.002, POn ) 'M1=1 after NOR (inverter) Call PulseOut(M2, 0.002, POff) 'M2=0 after NOR ( inverter) CallPulseOut(M4, 0.002, POn ) 'M4=1 after NOR ( inverter) '#2 CallPulseOut(M1, 0.002, POn ) 'M1=1 after NOR ( inverter) Call PulseOut(M2,0.002, POff) 'M2=0 after NOR ( inverter) Call PulseOut(M4, 0.002, POff)'M4=0 after NOR ( inverter) '#3 Call PulseOut(M1, 0.002, POn)'M1=1 after NOR ( inverter) Call PulseOut(M2, 0.002, POn) 'M2=1 afterNOR ( = inverter) Call PulseOut(M4, 0.002, POff) 'M4=0 after NOR ( = inverter)'#4Call PulseOut(M1, 0.002, POff) 'M1=0 after NOR ( = inverter) Call PulseOut(M2, 0.002, POn) 'M2=1 after NOR ( = inverter) Call PulseOut(M4, 0.002, POff) 'M4=0 after NOR ( = inverter)'#5 Call PulseOut(M1, 0.002, POff) 'M1=0 after NOR ( = inverter) Call PulseOut(M2, 0.002, POn) 'M2=1 after NOR ( = inverter) Call PulseOut(M4, 0.002, POn) 'M4=1 after NOR ( = inverter)'#6 Call PulseOut(M1, 0.002, POff) 'M1=0 after NOR ( = inverter) Call PulseOut(M2, 0.002, POff) 'M2=0 after NOR ( = inverter) Call PulseOut(M4, 0.002, POn) 'M4=1 after NOR ( = inverter) Next End Sub ----------- Also the diagram for the stepper motor control circuit. As you can see, there is enough pins available for more implementation.
if you can find the code and share, I will appreciate, so I can use as base formy own development.
Thanks
--- In b..., "Richard Friedrich" wrote: > I did this about 10 years ago > It used a rc airplane servo > It didn't use h-bridge > Generated the 1000-3000 > Directly with chip > Sent from my HTC on the Now Network from Sprint! > > ----- Reply message ----- > From: "erick soares de oliveira" > Date: Wed, Nov 24, 2010 6:22 pm > Subject: [BasicX] Digest Number 3131 > To: "No Reply" > Cc: "b..." > Still fighting to write some efficient code for the needle move smoothlyand > find any position in the speedometer. > > if anyone may have any suggestion or idea, let me know > > On Wed, Nov 24, 2010 at 11:47 AM, wrote: > > > Discussion list for the BasicX family of microcontroller chips > > > > Messages In This Digest (1 Message) > > 1a. Re: Help with Speedometer using stepper motor andBX24<#12c7e239131341c9_1a>From: Andrewdavid.mathison > > View AllTopics|Create > > NewTopic > > Message > > 1a. Re: Help with Speedometer using stepper motor and BX24 > >Posted > > by: "Andrewdavid.mathison" andrewdavid.mathison@... > > andrew.mathison > > Tue Nov 23, 2010 6:50 am > > (PST) > > > > > > Dear Richard Friedrich > > > > both links have been deleted.......try them yourself. > > > > Greetings from > > > > Andy Mathison > > > > > > > > Back to top <#12c7e239131341c9_toc> > > Reply to sender > >|Reply > > to group > >|Reply > > via web post > > > > Messages in this topic > >(3) > > Recent Activity > > > > - 2 > > NewMembers > > > > Visit Your Group > > > > Give Back > > > > Yahoo! forGood > > > > Get inspired > > > > by a good cause. > > Y! Toolbar > > > > Get itFree! > > > > easy 1-click access > > > > to your groups. > > Yahoo! Groups > > > > Start agroup > > > > in 3 easy steps. > > > > Connect with others. > > Need to Reply? > > > > Click one of the "Reply" links to respond to a specific message in the > > Daily Digest. > > Create New Topic > >|Visit > > Your Group on theWeb > > Messages| > >Files| > >Photos > > [image: Yahoo!Groups] > > Change settings via theWeb(Yahoo!ID required) > > Change settings via email: Switch delivery toIndividual| Switch > > format to Traditional > > Visit Your Group > >|Yahoo! > > Groups Terms of Use | Unsubscribe > > > > > > >
Hi guys, this weekend I worked in this project and could finally do a good piece ofsoftware to control the needle in the dash properly.Via test and evaluation, allspeeds are matching properly.
Now I will continue with a circuit and code to properly count speedo sensorpulses and convert to speed base.
I'm planning to use a regular clamping circuit with diodes and transistorto use as interface from the speed sensor to the BX-24 input. I expect to usethe "CountTransitions" for that.
Any recommendations or comments?
This is the software code I developed and worked fine:
Option Explicit
Const M1 as Byte = 12 Const M2 as Byte = 11 Const M4 as Byte = 10 Const POn as Byte = 0 Const POff as Byte = 1 '-------------------- Public Sub MoveNeedleUp ( ByRef NSpeed as Integer, ByRef NNeedlePos As Integer,ByRef NStep as Byte)
'--this section makes the needle move up '--according current position and '--desired speed target '--each step is the necessary stepper motor control
LOOP_UP: If (NStep=6) Then 'Step #1 NStep=1 NNeedlePos=NNeedlePos+1 Call PulseOut(M1, 0.001, POn ) Call PulseOut(M2, 0.001, POff) Call PulseOut(M4, 0.001, POn ) If (NNeedlePos=NSpeed) Then Goto LOOP_UP_END End if End If
If(NStep=1) Then 'Step #2 NStep=2 NNeedlePos=NNeedlePos+1 Call PulseOut(M1, 0.001, POn ) Call PulseOut(M2, 0.001, POff) Call PulseOut(M4, 0.001, POff) If (NNeedlePos=NSpeed) Then Goto LOOP_UP_END End if End If
If(NStep=2) Then 'Step #3 NStep=3 NNeedlePos=NNeedlePos+1 Call PulseOut(M1, 0.001, POn) Call PulseOut(M2, 0.001, POn) Call PulseOut(M4, 0.001, POff) If (NNeedlePos=NSpeed) Then Goto LOOP_UP_END End if End If
If(NStep=3) Then 'Step #4 NStep=4 NNeedlePos=NNeedlePos+1 Call PulseOut(M1, 0.001, POff) Call PulseOut(M2, 0.001, POn) Call PulseOut(M4, 0.001, POff) If (NNeedlePos=NSpeed) Then Goto LOOP_UP_END End if End If
If(NStep=4) Then 'Step #5 NStep=5 NNeedlePos=NNeedlePos+1 Call PulseOut(M1, 0.001, POff) Call PulseOut(M2, 0.001, POn) Call PulseOut(M4, 0.001, POn) If (NNeedlePos=NSpeed) Then Goto LOOP_UP_END End if End If
If(NStep=5) Then 'Step #6 NStep=6 NNeedlePos=NNeedlePos+1 Call PulseOut(M1, 0.001, POff) Call PulseOut(M2, 0.001, POff) Call PulseOut(M4, 0.001, POn) If (NNeedlePos=NSpeed) Then Goto LOOP_UP_END End if If (NNeedlePos<>NSpeed) Then Goto LOOP_UP End if End If
LOOP_UP_END: End Sub
'--------------------
Public Sub MoveNeedleDown ( ByRef NSpeed as Integer, ByRef NNeedlePos AsInteger, ByRef NStep as Byte)
'--this section makes the needle move down '--according current position and '--desired speed target '--each step is the necessary stepper motor control
LOOP_DOWN: If (NStep=1) Then 'Step #6 NStep=6 NNeedlePos=NNeedlePos-1 Call PulseOut(M1, 0.001, POff) Call PulseOut(M2, 0.001, POff) Call PulseOut(M4, 0.001, POn) If (NNeedlePos=NSpeed) Then Goto LOOP_DOWN_END End if End If
If (NStep=6) Then 'Step #5 NStep=5 NNeedlePos=NNeedlePos-1 Call PulseOut(M1, 0.001, POff) Call PulseOut(M2, 0.001, POn) Call PulseOut(M4, 0.001, POn) If (NNeedlePos=NSpeed) Then Goto LOOP_DOWN_END End if End If
If (NStep=5) Then 'Step #4 NStep=4 NNeedlePos=NNeedlePos-1 Call PulseOut(M1, 0.001, POff) Call PulseOut(M2, 0.001, POn) Call PulseOut(M4, 0.001, POff) If (NNeedlePos=NSpeed) Then Goto LOOP_DOWN_END End if End if
If (NStep=4) Then 'Step #3 NStep=3 NNeedlePos=NNeedlePos-1 Call PulseOut(M1, 0.001, POn) Call PulseOut(M2, 0.001, POn) Call PulseOut(M4, 0.001, POff) If (NNeedlePos=NSpeed) Then Goto LOOP_DOWN_END End if End if
If (NStep=3) Then 'Step #2 NStep=2 NNeedlePos=NNeedlePos-1 Call PulseOut(M1, 0.001, POn ) Call PulseOut(M2, 0.001, POff) Call PulseOut(M4, 0.001, POff) If (NNeedlePos=NSpeed) Then Goto LOOP_DOWN_END End if End if
If (NStep=2) Then 'Step #1 NStep=1 NNeedlePos=NNeedlePos-1 Call PulseOut(M1, 0.001, POn ) Call PulseOut(M2, 0.001, POff) Call PulseOut(M4, 0.001, POn ) If (NNeedlePos=NSpeed) Then Goto LOOP_DOWN_END End if If (NNeedlePos<>NSpeed) Then Goto LOOP_DOWN End if End if
LOOP_DOWN_END:
End Sub
'--------------------
Public Sub StartupDash () Dim n As Integer
'- this procedure makes the needle '- go up to 220km/h then go back '- down to 0km/h, similar to some '- cars, such as Lexus and others
'START force to go to initial state --0 For n = 1 to 10 '#6 Call PulseOut(M1, 0.001, POff) 'M1=0 ap inversor Call PulseOut(M2, 0.001, POff) 'M2=0 ap inversor Call PulseOut(M4, 0.001, POn) 'M3=1 ap inversor '#5 Call PulseOut(M1, 0.001, POff) 'M1=0 ap inversor Call PulseOut(M2, 0.001, POn) 'M2=1 ap inversor Call PulseOut(M4, 0.001, POn) 'M3=1 ap inversor '#4 Call PulseOut(M1, 0.001, POff) 'M1=0 ap inversor Call PulseOut(M2, 0.001, POn) 'M2=1 ap inversor Call PulseOut(M4, 0.001, POff) 'M3=0 ap inversor '#3 Call PulseOut(M1, 0.001, POn) 'M1=1 ap inversor Call PulseOut(M2, 0.001, POn) 'M2=1 ap inversor Call PulseOut(M4, 0.001, POff) 'M3=0 ap inversor '#2 Call PulseOut(M1, 0.001, POn ) 'M1=1 ap inversor Call PulseOut(M2, 0.001, POff) 'M2=0 ap inversor Call PulseOut(M4, 0.001, POff) 'M3=0 ap inversor '#1 Call PulseOut(M1, 0.001, POn ) 'M1=1 ap inversor Call PulseOut(M2, 0.001, POff) 'M2=0 ap inversor Call PulseOut(M4, 0.001, POn ) 'M3=1 ap inversor Next
'WAKE UP to 220km/h for n = 1 to 106 '#1 Call PulseOut(M1, 0.001, POn ) 'M1=1 ap inversor Call PulseOut(M2, 0.001, POff) 'M2=0 ap inversor Call PulseOut(M4, 0.001, POn ) 'M3=1 ap inversor '#2 Call PulseOut(M1, 0.001, POn ) 'M1=1 ap inversor Call PulseOut(M2, 0.001, POff) 'M2=0 ap inversor Call PulseOut(M4, 0.001, POff) 'M3=0 ap inversor '#3 Call PulseOut(M1, 0.001, POn) 'M1=1 ap inversor Call PulseOut(M2, 0.001, POn) 'M2=1 ap inversor Call PulseOut(M4, 0.001, POff) 'M3=0 ap inversor '#4 Call PulseOut(M1, 0.001, POff) 'M1=0 ap inversor Call PulseOut(M2, 0.001, POn) 'M2=1 ap inversor Call PulseOut(M4, 0.001, POff) 'M3=0 ap inversor '#5 Call PulseOut(M1, 0.001, POff) 'M1=0 ap inversor Call PulseOut(M2, 0.001, POn) 'M2=1 ap inversor Call PulseOut(M4, 0.001, POn) 'M3=1 ap inversor '#6 Call PulseOut(M1, 0.001, POff) 'M1=0 ap inversor Call PulseOut(M2, 0.001, POff) 'M2=0 ap inversor Call PulseOut(M4, 0.001, POn) 'M3=1 ap inversor Next
'WAKE UP DOWN to 0km/h For n = 1 to 104
'#6 Call PulseOut(M1, 0.001, POff) 'M1=0 ap inversor Call PulseOut(M2, 0.001, POff) 'M2=0 ap inversor Call PulseOut(M4, 0.001, POn) 'M3=1 ap inversor '#5 Call PulseOut(M1, 0.001, POff) 'M1=0 ap inversor Call PulseOut(M2, 0.001, POn) 'M2=1 ap inversor Call PulseOut(M4, 0.001, POn) 'M3=1 ap inversor '#4 Call PulseOut(M1, 0.001, POff) 'M1=0 ap inversor Call PulseOut(M2, 0.001, POn) 'M2=1 ap inversor Call PulseOut(M4, 0.001, POff) 'M3=0 ap inversor '#3 Call PulseOut(M1, 0.001, POn) 'M1=1 ap inversor Call PulseOut(M2, 0.001, POn) 'M2=1 ap inversor Call PulseOut(M4, 0.001, POff) 'M3=0 ap inversor '#2 Call PulseOut(M1, 0.001, POn ) 'M1=1 ap inversor Call PulseOut(M2, 0.001, POff) 'M2=0 ap inversor Call PulseOut(M4, 0.001, POff) 'M3=0 ap inversor '#1 Call PulseOut(M1, 0.001, POn ) 'M1=1 ap inversor Call PulseOut(M2, 0.001, POff) 'M2=0 ap inversor Call PulseOut(M4, 0.001, POn ) 'M3=1 ap inversor Next End Sub '-------------------- Public Sub Main() Dim TargetSpeed as Integer'speed value Dim NeedlePos as Integer'NeedlePos 0=0km/h to 612=220km/h Dim CurrentStep as Byte 'Step 1 to 6 Dim TempSpeed as Single Dim OnOffIgnition as Byte
POWER_LOOP: OnOffIgnition = GetPin(13) Do While ( OnOffIgnition=1 ) 'TempSpeed = CSng(CountTransitions (15, 40.0 ))
TempSpeed = 95.0 '- this value is for test purpose in the '- dashboard only. This should be removed '- in final code once CountTransitions is done
'TargetSpeed = FixI(TempSpeed*2.836364) '- total necessary steps = 624, from 0km/h '- up to 220km/h. So this represents '- a conversion factor of 624/220 = 2.836364 '- but in the real testing, for better '- accuracy, was used just 2.88 as bellow
TargetSpeed = FixI(TempSpeed*2.88) Debug.Print "speed= " ; CStr(TempSpeed) If (TargetSpeed > NeedlePos) Then Call MoveNeedleUp ( TargetSpeed , NeedlePos, CurrentStep) 'speed higher than needle position 'uses the sub procedure to make needle up 'NeddlePos = current needle position 'TargetSpeed = desired speed for needle position End If If (TargetSpeed < NeedlePos) Then Call MoveNeedleDown ( TargetSpeed , NeedlePos, CurrentStep) 'speed lower than needle position 'uses the sub procedure to make needle down 'NeddlePos = current needle position 'TargetSpeed = desired speed for needle position End If OnOffIgnition = GetPin(13) Loop
End If If (TargetSpeed < NeedlePos) Then Call MoveNeedleDown ( TargetSpeed , NeedlePos, CurrentStep) End If Goto POWER_LOOP End Sub
--- In b..., "Richard Friedrich" wrote: > > f/v are nice since it simplifies your programming. Also the LM2917 chip > goes to zero with zero input - this saves hassle of dealing with > overruns on very slow rotations. > > > > > > Richard > > > > From: b... [mailto:b...] On Behalf > Of ericksoliveira > Sent: Sunday, November 21, 2010 8:25 PM > To: b... > Subject: [BasicX] Help with Speedometer using stepper motor and BX24 > > > > > > I would like to ask some help here. > I have a personal car project (mix of track and street use) and would > like to build my own dashboard. > I know most of people would recommend to use a regular 7-segment display > for speedometer . However I want to keep the traditional look of analog > speedo with needle style. However the stepper motor offers high > precision. > I built a simple circuit with BX24 and Swisstec X25 stepper motor and > started playing with. It works fine. > Now I would like to ask for some help: > - any suggestion on which kind of circuit should I use to read the > gearbox electronic speedo sensor signal? I know it is a square wave > which modulates frequency according the speed. I believe most cars are > like this. I don't have any idea on how to connect the speedo signaland > process that data. Should I do a frequency-to-voltage converter? Or any > other idea? Or should I use just the BX24 to count pulses and make all > data processing to convert to the speedo signal information into pulses > for the stepper motor? > - any suggestion on software code to properly move the stepper motor > according the car speed? Should I do some internal register in software > so I know exactly where the needle is in the dash? I mean, should I > always know where the needle is exactly and how much up/down movement it > is necessary as next step? Because I need to control clockwise and > counter clockwise movements. > Any suggestion on how to proceed with this project? > Here is the simple code I did just to test the stepper motor and confirm > that basic circuit is working fine. > > -----------Option Explicit > Public Sub Main() > Dim n as integerConst M1 as Byte = 12 'this is the pin to drive Motor > Pin1Const M2 as Byte = 11 'this is the pin to drive Motor > Pin2=Pin3Const M4 as Byte = 10 'this is the pin to drive Motor > Pin4Const POn as Byte = 0 'NOR port working as inverter, so the logic > should be inverted.This case "Pulse On=0"Const POff as Byte = 1 'This > case "Pulse Off=1" > 'simple testing > for n = 1 to 50'#1 Call PulseOut(M1, 0.002, POn ) 'M1=1 after NOR (= > inverter) Call PulseOut(M2, 0.002, POff) 'M2=0 after NOR ( = > inverter) Call PulseOut(M4, 0.002, POn ) 'M4=1 after NOR ( = > inverter) '#2 Call PulseOut(M1, 0.002, POn ) 'M1=1 after NOR ( = > inverter) Call PulseOut(M2, 0.002, POff) 'M2=0 after NOR ( = > inverter) Call PulseOut(M4, 0.002, POff) 'M4=0 after NOR ( = > inverter) '#3 Call PulseOut(M1, 0.002, POn) 'M1=1 after NOR ( = > inverter) Call PulseOut(M2, 0.002, POn) 'M2=1 after NOR ( = inverter) > Call PulseOut(M4, 0.002, POff) 'M4=0 after NOR ( = inverter)'#4Call > PulseOut(M1, 0.002, POff) 'M1=0 after NOR ( = inverter) Call > PulseOut(M2, 0.002, POn) 'M2=1 after NOR ( = inverter) Call > PulseOut(M4, 0.002, POff) 'M4=0 after NOR ( = inverter)'#5 Call > PulseOut(M1, 0.002, POff) 'M1=0 after NOR ( = inverter) Call > PulseOut(M2, 0.002, POn) 'M2=1 after NOR ( = inverter) Call > PulseOut(M4, 0.002, POn) 'M4=1 after NOR ( = inverter)'#6 Call > PulseOut(M1, 0.002, POff) 'M1=0 after NOR ( = inverter) Call > PulseOut(M2, 0.002, POff) 'M2=0 after NOR ( = inverter) Call > PulseOut(M4, 0.002, POn) 'M4=1 after NOR ( = inverter) Next > End Sub > ----------- > Also the diagram for the stepper motor control circuit. As you can see, > there is enough pins available for more implementation. > >http://i8.photobucket.com/albums/a10/ericksoares/swapeando/Schematic01.j > \ > pg > > jpg> > > Thanks > Erick > > > > > > > > >
Reply byJim Fouch●December 12, 20102010-12-12
Here is an example of a motorcycle display replacement I did. I used a BX24 to read the pulses from both the speed sensor and tach. This was fed into a Parallax Propeller to do the graphics display. I used a 5" LCD display to display the composite signal the Propeller outputted.
From: b... [mailto:b...] On Behalf Of ericksoliveira Sent: Sunday, November 21, 2010 9:25 PM To: b... Subject: [BasicX] Help with Speedometer using stepper motor and BX24
I would like to ask some help here. I have a personal car project (mix of track and street use) and would like to build my own dashboard. I know most of people would recommend to use a regular 7-segment display for speedometer . However I want to keep the traditional look of analog speedo with needle style. However the stepper motor offers high precision. I built a simple circuit with BX24 and Swisstec X25 stepper motor and started playing with. It works fine. Now I would like to ask for some help: - any suggestion on which kind of circuit should I use to read the gearbox electronic speedo sensor signal? I know it is a square wave which modulates frequency according the speed. I believe most cars are like this. I don't have any idea on how to connect the speedo signal and process that data. Should I do a frequency-to-voltage converter? Or any other idea? Or should I use just the BX24 to count pulses and make all data processing to convert to the speedo signal information into pulses for the stepper motor? - any suggestion on software code to properly move the stepper motor according the car speed? Should I do some internal register in software so I know exactly where the needle is in the dash? I mean, should I always know where the needle is exactly and how much up/down movement it is necessary as next step? Because I need to control clockwise and counter clockwise movements. Any suggestion on how to proceed with this project? Here is the simple code I did just to test the stepper motor and confirm that basic circuit is working fine.
-----------Option Explicit Public Sub Main() Dim n as integerConst M1 as Byte = 12 'this is the pin to drive Motor Pin1Const M2 as Byte = 11 'this is the pin to drive Motor Pin2=Pin3Const M4 as Byte = 10 'this is the pin to drive Motor Pin4Const POn as Byte = 0 'NOR port working as inverter, so the logic should be inverted.This case "Pulse On=0"Const POff as Byte = 1 'This case "Pulse Off=1" 'simple testing for n = 1 to 50'#1 Call PulseOut(M1, 0.002, POn ) 'M1=1 after NOR (inverter) Call PulseOut(M2, 0.002, POff) 'M2=0 after NOR ( inverter) CallPulseOut(M4, 0.002, POn ) 'M4=1 after NOR ( inverter) '#2 CallPulseOut(M1, 0.002, POn ) 'M1=1 after NOR ( inverter) Call PulseOut(M2,0.002, POff) 'M2=0 after NOR ( inverter) Call PulseOut(M4, 0.002, POff)'M4=0 after NOR ( inverter) '#3 Call PulseOut(M1, 0.002, POn)'M1=1 after NOR ( inverter) Call PulseOut(M2, 0.002, POn) 'M2=1 afterNOR ( = inverter) Call PulseOut(M4, 0.002, POff) 'M4=0 after NOR ( = inverter)'#4Call PulseOut(M1, 0.002, POff) 'M1=0 after NOR ( = inverter) Call PulseOut(M2, 0.002, POn) 'M2=1 after NOR ( = inverter) Call PulseOut(M4, 0.002, POff) 'M4=0 after NOR ( = inverter)'#5 Call PulseOut(M1, 0.002, POff) 'M1=0 after NOR ( = inverter) Call PulseOut(M2, 0.002, POn) 'M2=1 after NOR ( = inverter) Call PulseOut(M4, 0.002, POn) 'M4=1 after NOR ( = inverter)'#6 Call PulseOut(M1, 0.002, POff) 'M1=0 after NOR ( = inverter) Call PulseOut(M2, 0.002, POff) 'M2=0 after NOR ( = inverter) Call PulseOut(M4, 0.002, POn) 'M4=1 after NOR ( = inverter) Next End Sub ----------- Also the diagram for the stepper motor control circuit. As you can see, there is enough pins available for more implementation.
Jim, thanks for sharing your project and information. That is a really niceproject... I was planning to do something based in a LCD screen but I gave upsince I had no experience with that and also with the fact that I would like tokeep the original dash. So now I will just control the stepper motor in theoriginal dash.
Can you share your experience in getting the speed and tacho signal from sensor?what kind of command did you use? I'm planning to use theCountTransitions, but not sure if that is a good idea.
My car is OBD2 compliant but since I removed the ABS for the rallye/trackpurpose, I now don't have the original speedo. that's why I 'mdoing this project to enable speedo.
Thanks
Erick
--- In b..., "Jim Fouch" wrote: > > Here is an example of a motorcycle display replacement I did. I used a BX24 > to read the pulses from both the speed sensor and tach. This was fed into a > Parallax Propeller to do the graphics display. I used a 5" LCD display to > display the composite signal the Propeller outputted. > > > > Here's a video of it running. >http://www.livevideo.com/video/AE6FB4F6991C418F80CD27CF8EEA4034/ultimate-mot > orcycle-gadget-ho.aspx > > > > Thanks, > > > > Jim > > > > From: b... [mailto:b...] On Behalf Of > ericksoliveira > Sent: Sunday, November 21, 2010 9:25 PM > To: b... > Subject: [BasicX] Help with Speedometer using stepper motor and BX24 > > > > > > I would like to ask some help here. > I have a personal car project (mix of track and street use) and would > like to build my own dashboard. > I know most of people would recommend to use a regular 7-segment display > for speedometer . However I want to keep the traditional look of analog > speedo with needle style. However the stepper motor offers high > precision. > I built a simple circuit with BX24 and Swisstec X25 stepper motor and > started playing with. It works fine. > Now I would like to ask for some help: > - any suggestion on which kind of circuit should I use to read the > gearbox electronic speedo sensor signal? I know it is a square wave > which modulates frequency according the speed. I believe most cars are > like this. I don't have any idea on how to connect the speedo signaland > process that data. Should I do a frequency-to-voltage converter? Or any > other idea? Or should I use just the BX24 to count pulses and make all > data processing to convert to the speedo signal information into pulses > for the stepper motor? > - any suggestion on software code to properly move the stepper motor > according the car speed? Should I do some internal register in software > so I know exactly where the needle is in the dash? I mean, should I > always know where the needle is exactly and how much up/down movement it > is necessary as next step? Because I need to control clockwise and > counter clockwise movements. > Any suggestion on how to proceed with this project? > Here is the simple code I did just to test the stepper motor and confirm > that basic circuit is working fine. > > Thanks > Erick
Reply byJim Fouch●December 14, 20102010-12-14
Erick,
I'll have to dig up the code I used to create the BX24 portion of that project. I think I just read the Pulse Width of each signal. Depending on the resolution of the PulseWidth command, and the output of the speed sensor you're trying to read. If the pulse width of the signal is too small for PulseIn to accurately read, then you will need to switch to CountTransitions. Each method has it's tradeoffs. Either one will tie upthe processor for a period of time while it's measuring. Another idea is touse an Interrupt and Increment a counter and at a specific time measure and reset the counter to zero.
With the Tach, the PulseIn will normally work well, because if the engine is running you will always have a good short pulse. However, with the speedometer, things get quite a bit different. Your pulses can remain at zero when the vehicle is not moving, or you will have very long pulses when it's moving very slowly. But, you will have to calculate how many transitions you will have at max speed. In my case, my bike has a top speed of 186MPH, so the pulses are coming at a very fast pace. The PulseIn function has a resolution of 1.085us. So lets say you have a signal that has a pulse width down to 1us. At max speed, you would not be able to measure the signal with much accuracy.
I'll try to see if I can find my old source for the speed / tach displayI did years ago. Also, once you measure these two sensors, you can calculate the gear also.
It read the both the speed & Tach and then calculated the gear based on the ratio between the two.
Thanks,
Jim
From: b... [mailto:b...] On Behalf Of ericksoliveira Sent: Monday, December 13, 2010 6:23 PM To: b... Subject: [BasicX] Re: Help with Speedometer using stepper motor and BX24
Jim, thanks for sharing your project and information. That is a really nice project... I was planning to do something based in a LCD screen but I gave up since I had no experience with that and also with the fact that I would like to keep the original dash. So now I will just control the stepper motor in the original dash.
Can you share your experience in getting the speed and tacho signal from sensor? what kind of command did you use? I'm planning to use the CountTransitions, but not sure if that is a good idea.
My car is OBD2 compliant but since I removed the ABS for the rallye/track purpose, I now don't have the original speedo. that's why I 'mdoing this project to enable speedo.
Thanks
Erick
--- In b... , "Jim Fouch" wrote: > > Here is an example of a motorcycle display replacement I did. I used a BX24 > to read the pulses from both the speed sensor andtach. This was fed into a > Parallax Propeller to do the graphics display. I useda 5" LCD display to > display the composite signal the Propeller outputted. > > Here's a video of it running. > http://www.livevideo.com/video/AE6FB4F6991C418F80CD27CF8EEA4034/ultimate-mot > orcycle-gadget-ho.aspx > > Thanks, > > Jim > > From: b... [mailto:b... ] On Behalf Of > ericksoliveira > Sent: Sunday, November 21, 2010 9:25 PM > To: b... > Subject: [BasicX] Help with Speedometer using stepper motor and BX24 > > I would like to ask some help here. > I have a personal car project (mix of track and street use) and would > like to build my own dashboard. > I know most of people would recommend to use a regular 7-segment display > for speedometer . However I want to keep the traditional look of analog > speedo with needle style. However the stepper motor offers high > precision. > I built a simple circuit with BX24 and Swisstec X25 stepper motor and > started playing with. It works fine. > Now I would like to ask for some help: > - any suggestion on which kind of circuit should I use to read the > gearbox electronic speedo sensor signal? I know it is a square wave > which modulates frequency according the speed. I believe most cars are > like this. I don't have any idea on how to connect the speedo signaland > process that data. Should I do a frequency-to-voltage converter? Or any > other idea? Or should I use just the BX24 to count pulses and make all > data processing to convert to the speedo signal information into pulses > for the stepper motor? > - any suggestion on software code to properly move the stepper motor > according the car speed? Should I do some internal register in software > so I know exactly where the needle is in the dash? I mean, should I > always know where the needle is exactly and how much up/down movement it > is necessary as next step? Because I need to control clockwise and > counter clockwise movements. > Any suggestion on how to proceed with this project? > Here is the simple code I did just to test the stepper motor and confirm > that basic circuit is working fine. > > Thanks > Erick
Reply byericksoliveira●January 8, 20112011-01-08
Thanks for everyone help so far.
I could build the circuit and install into my car. After some fine tuning intothe constants, it is working with a good accuracy for speedo.
My only problem now: The stepper motor is too fast and also the gearbox sensor reading... so if I letthe BX24 to read the input signal from the gearbox sensor (either usingPulseWidth or CountTransitions) the needle in the speedo is moving too fast backand forth. That happens because once the data comes, it is not being processedor filtered anyway. It just send to the stepper motor...
I believe I should process and filter the data somehow.
My original program was reading the sensor in a 0.1s basis, so 10 samples /second. I kept the rate, but was doing an average from 5 samples. So steppermotor went down to 2 samples/s ( 0.5seconds / interval).
My experience so far: - if I let the software to read sensor signal and send to stepper motor, theneedle is moving back and forth, with some big movements up and down. It is nota linear and smooth movement. - I then tried reading 5 samples and making and average to send to thedashboard. Now at least the needle is not going up and down so quick andcrazy... But the movement is not smooth yet.
Any suggestion about how I could process the data to have a linear and smoothneedle movement?
Here is a link with the video for the final setup: it has my project running andby the end of the video I recorded another car as an example to show the smoothmovement that I expect for the needle.
Here is the software code without the average for 5 samples :
Option Explicit
Const M1 as Byte = 12 Const M2 as Byte = 11 Const M4 as Byte = 10 Const POn as Byte = 0 Const POff as Byte = 1 '-------------------- Public Sub MoveNeedleUp ( ByRef NSpeed as Integer, ByRef NNeedlePos As Integer,ByRef NStep as Byte)
LOOP_UP: If (NStep=6) Then 'Step #1 NStep=1 NNeedlePos=NNeedlePos+1 Call PulseOut(M1, 0.001, POn ) 'M1=1 ap inversor Call PulseOut(M2, 0.001, POff) 'M2=0 ap inversor Call PulseOut(M4, 0.001, POn ) 'M3=1 ap inversor If (NNeedlePos=NSpeed) Then Goto LOOP_UP_END End if End If
If(NStep=1) Then 'Step #2 NStep=2 NNeedlePos=NNeedlePos+1 Call PulseOut(M1, 0.001, POn ) 'M1=1 ap inversor Call PulseOut(M2, 0.001, POff) 'M2=0 ap inversor Call PulseOut(M4, 0.001, POff) 'M3=0 ap inversor If (NNeedlePos=NSpeed) Then Goto LOOP_UP_END End if End If
If(NStep=2) Then 'Step #3 NStep=3 NNeedlePos=NNeedlePos+1 Call PulseOut(M1, 0.001, POn) 'M1=1 ap inversor Call PulseOut(M2, 0.001, POn) 'M2=1 ap inversor Call PulseOut(M4, 0.001, POff) 'M3=0 ap inversor If (NNeedlePos=NSpeed) Then Goto LOOP_UP_END End if End If
If(NStep=3) Then 'Step #4 NStep=4 NNeedlePos=NNeedlePos+1 Call PulseOut(M1, 0.001, POff) 'M1=0 ap inversor Call PulseOut(M2, 0.001, POn) 'M2=1 ap inversor Call PulseOut(M4, 0.001, POff) 'M3=0 ap inversor If (NNeedlePos=NSpeed) Then Goto LOOP_UP_END End if End If
If(NStep=4) Then 'Step #5 NStep=5 NNeedlePos=NNeedlePos+1 Call PulseOut(M1, 0.001, POff) 'M1=0 ap inversor Call PulseOut(M2, 0.001, POn) 'M2=1 ap inversor Call PulseOut(M4, 0.001, POn) 'M3=1 ap inversor If (NNeedlePos=NSpeed) Then Goto LOOP_UP_END End if End If
If(NStep=5) Then 'Step #6 NStep=6 NNeedlePos=NNeedlePos+1 Call PulseOut(M1, 0.001, POff) 'M1=0 ap inversor Call PulseOut(M2, 0.001, POff) 'M2=0 ap inversor Call PulseOut(M4, 0.001, POn) 'M3=1 ap inversor If (NNeedlePos=NSpeed) Then Goto LOOP_UP_END End if If (NNeedlePos<>NSpeed) Then Goto LOOP_UP End if End If
LOOP_UP_END: End Sub
'--------------------
Public Sub MoveNeedleDown ( ByRef NSpeed as Integer, ByRef NNeedlePos AsInteger, ByRef NStep as Byte)
LOOP_DOWN: If (NStep=1) Then 'Step #6 NStep=6 NNeedlePos=NNeedlePos-1 Call PulseOut(M1, 0.001, POff) 'M1=0 Call PulseOut(M2, 0.001, POff) 'M2=0 Call PulseOut(M4, 0.001, POn) 'M3=1 If (NNeedlePos=NSpeed) Then Goto LOOP_DOWN_END End if End If
If (NStep=6) Then 'Step #5 NStep=5 NNeedlePos=NNeedlePos-1 Call PulseOut(M1, 0.001, POff) 'M1=0 Call PulseOut(M2, 0.001, POn) 'M2=1 Call PulseOut(M4, 0.001, POn) 'M3=1 If (NNeedlePos=NSpeed) Then Goto LOOP_DOWN_END End if End If
If (NStep=5) Then 'Step #4 NStep=4 NNeedlePos=NNeedlePos-1 Call PulseOut(M1, 0.001, POff) 'M1=0 Call PulseOut(M2, 0.001, POn) 'M2=1 Call PulseOut(M4, 0.001, POff) 'M3=0 If (NNeedlePos=NSpeed) Then Goto LOOP_DOWN_END End if End if
If (NStep=4) Then 'Step #3 NStep=3 NNeedlePos=NNeedlePos-1 Call PulseOut(M1, 0.001, POn) 'M1=1 Call PulseOut(M2, 0.001, POn) 'M2=1 Call PulseOut(M4, 0.001, POff) 'M3=0 If (NNeedlePos=NSpeed) Then Goto LOOP_DOWN_END End if End if
If (NStep=3) Then 'Step #2 NStep=2 NNeedlePos=NNeedlePos-1 Call PulseOut(M1, 0.001, POn ) 'M1=1 Call PulseOut(M2, 0.001, POff) 'M2=0 Call PulseOut(M4, 0.001, POff) 'M3=0 If (NNeedlePos=NSpeed) Then Goto LOOP_DOWN_END End if End if
If (NStep=2) Then 'Step #1 NStep=1 NNeedlePos=NNeedlePos-1 Call PulseOut(M1, 0.001, POn ) 'M1=1 Call PulseOut(M2, 0.001, POff) 'M2=0 Call PulseOut(M4, 0.001, POn ) 'M3=1 If (NNeedlePos=NSpeed) Then Goto LOOP_DOWN_END End if If (NNeedlePos<>NSpeed) Then Goto LOOP_DOWN End if End if
LOOP_DOWN_END:
End Sub
'--------------------
Public Sub StartupDash () Dim n As Integer 'START force to go to initial state --0 For n = 1 to 10 '#6 Call PulseOut(M1, 0.001, POff) 'M1=0 Call PulseOut(M2, 0.001, POff) 'M2=0 Call PulseOut(M4, 0.001, POn) 'M3=1 '#5 Call PulseOut(M1, 0.001, POff) 'M1=0 Call PulseOut(M2, 0.001, POn) 'M2=1 Call PulseOut(M4, 0.001, POn) 'M3=1 '#4 Call PulseOut(M1, 0.001, POff) 'M1=0 Call PulseOut(M2, 0.001, POn) 'M2=1 Call PulseOut(M4, 0.001, POff) 'M3=0 '#3 Call PulseOut(M1, 0.001, POn) 'M1=1 Call PulseOut(M2, 0.001, POn) 'M2=1 Call PulseOut(M4, 0.001, POff) 'M3=0 '#2 Call PulseOut(M1, 0.001, POn ) 'M1=1 Call PulseOut(M2, 0.001, POff) 'M2=0 Call PulseOut(M4, 0.001, POff) 'M3=0 '#1 Call PulseOut(M1, 0.001, POn ) 'M1=1 Call PulseOut(M2, 0.001, POff) 'M2=0 Call PulseOut(M4, 0.001, POn ) 'M3=1 Next
'#6 Call PulseOut(M1, 0.001, POff) 'M1=0 Call PulseOut(M2, 0.001, POff) 'M2=0 Call PulseOut(M4, 0.001, POn) 'M3=1 '#5 Call PulseOut(M1, 0.001, POff) 'M1=0 Call PulseOut(M2, 0.001, POn) 'M2=1 Call PulseOut(M4, 0.001, POn) 'M3=1 '#4 Call PulseOut(M1, 0.001, POff) 'M1=0 Call PulseOut(M2, 0.001, POn) 'M2=1 Call PulseOut(M4, 0.001, POff) 'M3=0 '#3 Call PulseOut(M1, 0.001, POn) 'M1=1 Call PulseOut(M2, 0.001, POn) 'M2=1 Call PulseOut(M4, 0.001, POff) 'M3=0 '#2 Call PulseOut(M1, 0.001, POn ) 'M1=1 Call PulseOut(M2, 0.001, POff) 'M2=0 Call PulseOut(M4, 0.001, POff) 'M3=0 '#1 Call PulseOut(M1, 0.001, POn ) 'M1=1 Call PulseOut(M2, 0.001, POff) 'M2=0 Call PulseOut(M4, 0.001, POn ) 'M3=1 Next End Sub '-------------------- Public Sub Main() Dim TargetSpeed as Integer'speed value as target for needle Dim NeedlePos as Integer'NeedlePos 0=0km/h to 612=220km/h Dim CurrentStep as Byte 'Step 1 to 6 for step motor/neddle Dim TempSpeed as Single'speed from sensor input Dim OnOffLogic as Byte'logic to enable main program loop Dim PulseWidth as Single' Dim T as Single Dim PulsePerSec as Single Dim TireCircunf as Single Dim RevsPerKm as Single Dim PPK as Single Dim PulsePerREV as Single Dim REVperSec as Single Dim Space as Single
Call StartupDash () TargetSpeed = 0 NeedlePos = 0 CurrentStep = 6 Call PutPin (13, bxInputPullup)'from here on values are forcalibration TireCircunf=1.8096'195/50R15= 1.8096m or 205/40R17= 1.8718m REVsPerKm = 1000.0/TireCircunf' 1000m / tire circunference PPK = 5478.0'pulses per Km with 195/50R15 tire PulsePerREV = PPK/REVsPerKm' Pulses Per tire Revolution
POWER_LOOP: Call PulseIn(13,1,PulseWidth)'measure pulse width for tH T= PulseWidth*2.0 'assumes tH=tL and T=th+tl PulsePerSec = 1.0/T'pulses qty = pulses frequency REVperSec = PulsePerSec/PulsePerREV'revolutions per second Space = TireCircunf* REVperSec'results in m/s TempSpeed = Space * 3.6' results in km/h
TargetSpeed = FixI(TempSpeed*2.88) Debug.Print "velocidade= " ; CStr(TempSpeed) If (TargetSpeed > NeedlePos) Then Call MoveNeedleUp ( TargetSpeed , NeedlePos, CurrentStep) 'procedure to move needle up 'in case needle target speed is bigger than 'current needle position 'NeddlePos = current needle position 'TargetSpeed = desired needle position based on speed End If If (TargetSpeed < NeedlePos) Then Call MoveNeedleDown ( TargetSpeed , NeedlePos, CurrentStep) 'procedure to move needle down 'in case needle target speed is lower than 'current needle position 'NeddlePos = current needle position 'TargetSpeed = desired needle position based on speed
End If
Goto POWER_LOOP End Sub
Reply byrosa...@aol.com●January 9, 20112011-01-09
Hi, How do you read the speed from the gearbox? Are you using a magnetic pickup ?Did you check it for noises? It is possible that the reading from the sensor is noisy that will make thereading like you described it. If you are reading the sensor from a pickupsensor is good idea to use a schmitt trigger like the 7414. It will square thesignal coming from the sensor. Check the spec. for the 7414.
Regards, rosarite
-----Original Message----- From: ericksoliveira To: basicx Sent: Sat, Jan 8, 2011 9:31 pm Subject: [BasicX] Re: Help with Speedometer using stepper motor and BX24
Thanks for everyone help so far.
I could build the circuit and install into my car. After some fine tuning intothe constants, it is working with a good accuracy for speedo.
My only problem now: The stepper motor is too fast and also the gearbox sensor reading... so if I letthe BX24 to read the input signal from the gearbox sensor (either usingPulseWidth or CountTransitions) the needle in the speedo is moving too fast backand forth. That happens because once the data comes, it is not being processedor filtered anyway. It just send to the stepper motor...
I believe I should process and filter the data somehow.
My original program was reading the sensor in a 0.1s basis, so 10 samples /second. I kept the rate, but was doing an average from 5 samples. So steppermotor went down to 2 samples/s ( 0.5seconds / interval).
My experience so far: - if I let the software to read sensor signal and send to stepper motor, theneedle is moving back and forth, with some big movements up and down. It is nota linear and smooth movement. - I then tried reading 5 samples and making and average to send to thedashboard. Now at least the needle is not going up and down so quick andcrazy... But the movement is not smooth yet.
Any suggestion about how I could process the data to have a linear and smoothneedle movement?
Here is a link with the video for the final setup: it has my project running andby the end of the video I recorded another car as an example to show the smoothmovement that I expect for the needle.
Here is the software code without the average for 5 samples :
Option Explicit
Const M1 as Byte = 12 Const M2 as Byte = 11 Const M4 as Byte = 10 Const POn as Byte = 0 Const POff as Byte = 1
'-------------------- Public Sub MoveNeedleUp ( ByRef NSpeed as Integer, ByRef NNeedlePos As Integer,ByRef NStep as Byte)
LOOP_UP: If (NStep=6) Then 'Step #1 NStep=1 NNeedlePos=NNeedlePos+1 Call PulseOut(M1, 0.001, POn ) 'M1=1 após inversor Call PulseOut(M2, 0.001, POff) 'M2=0 após inversor Call PulseOut(M4, 0.001, POn ) 'M3=1 após inversor If (NNeedlePos=NSpeed) Then Goto LOOP_UP_END End if End If
If(NStep=1) Then 'Step #2 NStep=2 NNeedlePos=NNeedlePos+1 Call PulseOut(M1, 0.001, POn ) 'M1=1 após inversor Call PulseOut(M2, 0.001, POff) 'M2=0 após inversor Call PulseOut(M4, 0.001, POff) 'M3=0 após inversor If (NNeedlePos=NSpeed) Then Goto LOOP_UP_END End if End If
If(NStep=2) Then 'Step #3 NStep=3 NNeedlePos=NNeedlePos+1 Call PulseOut(M1, 0.001, POn) 'M1=1 após inversor Call PulseOut(M2, 0.001, POn) 'M2=1 após inversor Call PulseOut(M4, 0.001, POff) 'M3=0 após inversor If (NNeedlePos=NSpeed) Then Goto LOOP_UP_END End if End If
If(NStep=3) Then 'Step #4 NStep=4 NNeedlePos=NNeedlePos+1 Call PulseOut(M1, 0.001, POff) 'M1=0 após inversor Call PulseOut(M2, 0.001, POn) 'M2=1 após inversor Call PulseOut(M4, 0.001, POff) 'M3=0 após inversor If (NNeedlePos=NSpeed) Then Goto LOOP_UP_END End if End If
If(NStep=4) Then 'Step #5 NStep=5 NNeedlePos=NNeedlePos+1 Call PulseOut(M1, 0.001, POff) 'M1=0 após inversor Call PulseOut(M2, 0.001, POn) 'M2=1 após inversor Call PulseOut(M4, 0.001, POn) 'M3=1 após inversor If (NNeedlePos=NSpeed) Then Goto LOOP_UP_END End if End If
If(NStep=5) Then 'Step #6 NStep=6 NNeedlePos=NNeedlePos+1 Call PulseOut(M1, 0.001, POff) 'M1=0 após inversor Call PulseOut(M2, 0.001, POff) 'M2=0 após inversor Call PulseOut(M4, 0.001, POn) 'M3=1 após inversor If (NNeedlePos=NSpeed) Then Goto LOOP_UP_END End if If (NNeedlePos<>NSpeed) Then Goto LOOP_UP End if End If
LOOP_UP_END: End Sub
'--------------------
Public Sub MoveNeedleDown ( ByRef NSpeed as Integer, ByRef NNeedlePos AsInteger, ByRef NStep as Byte)
LOOP_DOWN: If (NStep=1) Then 'Step #6 NStep=6 NNeedlePos=NNeedlePos-1 Call PulseOut(M1, 0.001, POff) 'M1=0 Call PulseOut(M2, 0.001, POff) 'M2=0 Call PulseOut(M4, 0.001, POn) 'M3=1 If (NNeedlePos=NSpeed) Then Goto LOOP_DOWN_END End if End If
If (NStep=6) Then 'Step #5 NStep=5 NNeedlePos=NNeedlePos-1 Call PulseOut(M1, 0.001, POff) 'M1=0 Call PulseOut(M2, 0.001, POn) 'M2=1 Call PulseOut(M4, 0.001, POn) 'M3=1 If (NNeedlePos=NSpeed) Then Goto LOOP_DOWN_END End if End If
If (NStep=5) Then 'Step #4 NStep=4 NNeedlePos=NNeedlePos-1 Call PulseOut(M1, 0.001, POff) 'M1=0 Call PulseOut(M2, 0.001, POn) 'M2=1 Call PulseOut(M4, 0.001, POff) 'M3=0 If (NNeedlePos=NSpeed) Then Goto LOOP_DOWN_END End if End if
If (NStep=4) Then 'Step #3 NStep=3 NNeedlePos=NNeedlePos-1 Call PulseOut(M1, 0.001, POn) 'M1=1 Call PulseOut(M2, 0.001, POn) 'M2=1 Call PulseOut(M4, 0.001, POff) 'M3=0 If (NNeedlePos=NSpeed) Then Goto LOOP_DOWN_END End if End if
If (NStep=3) Then 'Step #2 NStep=2 NNeedlePos=NNeedlePos-1 Call PulseOut(M1, 0.001, POn ) 'M1=1 Call PulseOut(M2, 0.001, POff) 'M2=0 Call PulseOut(M4, 0.001, POff) 'M3=0 If (NNeedlePos=NSpeed) Then Goto LOOP_DOWN_END End if End if
If (NStep=2) Then 'Step #1 NStep=1 NNeedlePos=NNeedlePos-1 Call PulseOut(M1, 0.001, POn ) 'M1=1 Call PulseOut(M2, 0.001, POff) 'M2=0 Call PulseOut(M4, 0.001, POn ) 'M3=1 If (NNeedlePos=NSpeed) Then Goto LOOP_DOWN_END End if If (NNeedlePos<>NSpeed) Then Goto LOOP_DOWN End if End if
LOOP_DOWN_END:
End Sub
'--------------------
Public Sub StartupDash () Dim n As Integer 'START force to go to initial state --0 For n = 1 to 10 '#6 Call PulseOut(M1, 0.001, POff) 'M1=0 Call PulseOut(M2, 0.001, POff) 'M2=0 Call PulseOut(M4, 0.001, POn) 'M3=1 '#5 Call PulseOut(M1, 0.001, POff) 'M1=0 Call PulseOut(M2, 0.001, POn) 'M2=1 Call PulseOut(M4, 0.001, POn) 'M3=1 '#4 Call PulseOut(M1, 0.001, POff) 'M1=0 Call PulseOut(M2, 0.001, POn) 'M2=1 Call PulseOut(M4, 0.001, POff) 'M3=0 '#3 Call PulseOut(M1, 0.001, POn) 'M1=1 Call PulseOut(M2, 0.001, POn) 'M2=1 Call PulseOut(M4, 0.001, POff) 'M3=0 '#2 Call PulseOut(M1, 0.001, POn ) 'M1=1 Call PulseOut(M2, 0.001, POff) 'M2=0 Call PulseOut(M4, 0.001, POff) 'M3=0 '#1 Call PulseOut(M1, 0.001, POn ) 'M1=1 Call PulseOut(M2, 0.001, POff) 'M2=0 Call PulseOut(M4, 0.001, POn ) 'M3=1 Next
'-------------------- Public Sub Main() Dim TargetSpeed as Integer'speed value as target for needle Dim NeedlePos as Integer'NeedlePos 0=0km/h to 612=220km/h Dim CurrentStep as Byte 'Step 1 to 6 for step motor/neddle Dim TempSpeed as Single'speed from sensor input Dim OnOffLogic as Byte'logic to enable main program loop Dim PulseWidth as Single' Dim T as Single Dim PulsePerSec as Single Dim TireCircunf as Single Dim RevsPerKm as Single Dim PPK as Single Dim PulsePerREV as Single Dim REVperSec as Single Dim Space as Single
Call StartupDash () TargetSpeed = 0 NeedlePos = 0 CurrentStep = 6 Call PutPin (13, bxInputPullup)'from here on values are forcalibration TireCircunf=1.8096'195/50R15= 1.8096m or 205/40R17= 1.8718m REVsPerKm = 1000.0/TireCircunf' 1000m / tire circunference PPK = 5478.0'pulses per Km with 195/50R15 tire PulsePerREV = PPK/REVsPerKm' Pulses Per tire Revolution
POWER_LOOP: Call PulseIn(13,1,PulseWidth)'measure pulse width for tH T= PulseWidth*2.0 'assumes tH=tL and T=th+tl PulsePerSec = 1.0/T'pulses qty = pulses frequency REVperSec = PulsePerSec/PulsePerREV'revolutions per second Space = TireCircunf* REVperSec'results in m/s TempSpeed = Space * 3.6' results in km/h
TargetSpeed = FixI(TempSpeed*2.88) Debug.Print "velocidade= " ; CStr(TempSpeed) If (TargetSpeed > NeedlePos) Then Call MoveNeedleUp ( TargetSpeed , NeedlePos, CurrentStep) 'procedure to move needle up 'in case needle target speed is bigger than 'current needle position 'NeddlePos = current needle position 'TargetSpeed = desired needle position based on speed End If If (TargetSpeed < NeedlePos) Then Call MoveNeedleDown ( TargetSpeed , NeedlePos, CurrentStep) 'procedure to move needle down 'in case needle target speed is lower than 'current needle position 'NeddlePos = current needle position 'TargetSpeed = desired needle position based on speed
