Repository files navigation

git submodule update --init --recursiveexport PICO_SDK_PATH=/path/to/your/pico-sdkmkdir buildcd buildcmake ..make

More complete info can be extracted from GitHub actionscript.

A simple app demonstrating the use of PIO and DMA forefficient data transfers to a 480x320 TFT display.The graphics library creates a monochromatic imagein memory which is expanded to 16-bit color codesin PIO block and transferred via 8-bit parallelinterface.

A simple app controlled by one button, controllinga WS2812 strip/matrix. Can be used to test strips/matrices.

Reading audio from a INMP441 MEMS microphone using PIO+DMA,computing fixed point FFT (CMSIS-DSP) and displaying an ASCIIspectrogram on serial.

TFLMMicro Speechmodel is ported to Raspberry Pi Pico (RP2040, Cortex-M0+). Sound is from a MEMSI2S microphone (INMP441). The CPU is clocked at 250MHz. Data fromthe microphone is transferred using PIO+DMA. With this configuration real-timespeech analysis is possible (stride is 20ms at 16kHz sample rate and single inference takes ~19ms).

TinyML keyword spotting demo. The model isShallow RNNarchitecture with aFastGRNN cell convertedto ~200 lines of C code.At 280MHz Core0 is setting up DMA transfers from I2S microphoneand doing feature extraction (dc blocking ->preemphasis ->FFT ->power ->log ->Mel filterbank)in frames, nine frames a second.

The core utilization is ~70%.Core1 every 105ms does NN inference which takes about 85ms (77% core utilization).

The microphone (INMP441) connections are as follows:

tinygl_1b test app (ditheredglxgears)

tinygl_1b test app - model exported from Blender.

Real time /pitch shifter/voice changer/ application. Pitch shifting code generated inFaust.As a bonus there are also vibrato and echo effects. Short button presses cycle through the pitch levels.Long button press between 500ms-2000ms activates and deactivates echo.Button press longer than 2000ms activates the vibrato.

Example recording:

INMP441 microphone connections are like in therpi_inmp441_kws application:

Audio output via GPIO PWM pin with a low-pass filter:

LM386 or PAM8403 can be used to amplify further, to connect a speaker.A tact switch needs to be connected betweenGP13 andGND.