This part of the series will be an application of the preceding part, which enabled our project to receive commands remotely via Bluetooth.

Table of Contents

• Requirements
• Implementation
• Connections
• Results

Requirements

• 1 x Raspberry Pi Pico board
• 1 x USB Cable type 2.0
• 1 x HC-05 Bluetooth module
• 10 x M-M jumper wires
• 2 x Mini Breadboards
• Serial Bluetooth Terminal App

Implementation

In themain part of the program, under the super loop, we need to check whether we are inauto ormanual mode. We'll also need to enter a critical section since shared variables will be used. 

Add handles foruart_cmd anddirection.

cortex_m::interrupt::free(|cs|{letmutdirection=DIRECTION.borrow(cs).borrow_mut();letmutuart_cmd=UARTCMD.borrow(cs).borrow_mut();ifAUTO.borrow(cs).get(){// Auto mode}else{// Manual mode}});

Then add the following under theauto andmanual arms respectively:

writeln!(&mutserialbuf,"auto mode").unwrap();transmit_uart_cmd(uart_cmd.as_mut().unwrap(),serialbuf);writeln!(&mutserialbuf,"manual mode").unwrap();transmit_uart_cmd(uart_cmd.as_mut().unwrap(),serialbuf);

Undermanual mode, we'll add the below code that applies our algorithm.

// manual modematchdirection.as_mut(){Some(Direction::Cw)=>{*direction=None;// reset directionwriteln!(&mutserialbuf,"manual mode: cw").unwrap();transmit_uart_cmd(uart_cmd.as_mut().unwrap(),serialbuf);},Some(Direction::Ccw)=>{*direction=None;writeln!(&mutserialbuf,"manual mode: ccw").unwrap();transmit_uart_cmd(uart_cmd.as_mut().unwrap(),serialbuf);},Some(Direction::Up)=>{*direction=None;writeln!(&mutserialbuf,"manual mode: up").unwrap();transmit_uart_cmd(uart_cmd.as_mut().unwrap(),serialbuf);},Some(Direction::Down)=>{*direction=None;writeln!(&mutserialbuf,"manual mode: down").unwrap();transmit_uart_cmd(uart_cmd.as_mut().unwrap(),serialbuf);},Some(Direction::Zero)=>{*direction=None;writeln!(&mutserialbuf,"manual mode: position zero").unwrap();transmit_uart_cmd(uart_cmd.as_mut().unwrap(),serialbuf);},None=>{},}

Connections

The connections will remain the same as from the previous part of the series.

Results

After rearranging our code we will getthis final copy.

Here are highlights of changes from the previous program.

Running this program will flash it into the Pico, and we'll be set to receive commands remotely via Bluetooth.

We can see that while inauto mode any further received commands other thanA are not consequential.

Inmanual mode the system responds appropriately to further commands.

Next we will set up our system to receive GPS data from the Neo-6m GPS module.