Audio Level Meter for rp2040

Overview

This is Audio Level Meter library for rp2040

This project feattures:

• Analog signal input for multiple channels (max 3 channels)
• Configurable dB scale steps and levels

Supported Board

• Waveshare RP2040-LCD-0.96 Board (ST7735S 80x160 LCD build-in) or
• Raspberry Pi Pico + ST7735S 80x160 LCD

Pin Assignment

ST7735S 80x160 LCD (Waveshare RP2040-LCD-0.96 Board)

Pin #	Pin Name	Function	Signal Name
11	GP8	GPIO	DC
12	GP9	SPI1_CSn	CS
14	GP10	SPI1_SCK	SCL
15	GP11	SPI1_TX	DIN
16	GP12	GPIO	RST
--	GP25	GPIO	BL

Schematic

The frontend analog circuit should be needed.

pico_level_meter.pdf

How to build

• See "Getting started with Raspberry Pi Pico"
• Put "pico-sdk", "pico-examples" and "pico-extras" on the same level with this project folder.
• Set environmental variables for PICO_SDK_PATH, PICO_EXTRAS_PATH and PICO_EXAMPLES_PATH
• Build is confirmed in Developer Command Prompt for VS 2022 and Visual Studio Code on Windows enviroment
• Confirmed with Pico SDK 1.5.1, cmake-3.27.2-windows-x86_64 and gcc-arm-none-eabi-10.3-2021.10-win32

> git clone -b master https://github.com/raspberrypi/pico-sdk.git
> cd pico-sdk
> git submodule update -i
> cd ..
> git clone -b master https://github.com/raspberrypi/pico-examples.git
> 
> git clone -b main https://github.com/elehobica/pico_level_meter.git
> cd pico_level_meter
> git submodule update -i
> cd ..

• Lanuch "Developer Command Prompt for VS 2022"

> cd pico_level_meter
> mkdir build
> cd build
> cmake -G "NMake Makefiles" ..
> nmake

• Put "pico_level_meter.uf2" on RPI-RP2 drive

Peak Hold

• push any key on serial terminal to toggle peak hold mode