PicoRuby RP2040 Peripheral Demo

Peripherals

• GPIO: Raspberr Pi Pico on-board LED
• UART: FTDI USB to TTL Serial Adapter Cable (3.3V)
• I2C: PCF8523 RTC module
• ADC: RP2040 on-chip temperature sensor

Wiring

Note: The wire colors in the picture and in the table are different.

Function	Raspi Pico	Peripheral
GPIO	GPIO 25 (Connected internally)	LED
UART	GPIO 0	Serial Adapter RX (Yellow)
UART	GPIO 1	Serial Adapter TX (Orange)
UART	GND	Serial Adapter GND (Black)
	VBUS(5V)	Serial Adapter VCC (Red)1
I2C	GPIO 4	PCF8523 SDA
I2C	GPIO 5	PCF8523 SCL
I2C	GND	PCF8523 GND
I2C	VBUS(5V)2	PCF8523 VCC
ADC	ADC4 (Connected internally)	Temperature sensor

Build by yourself or use a release binary

Prerequisites

• CMake
• raspberrypi/pico-sdk
  • tag 1.5.0
  • PICO_SDK_PATH
• Raspberry Pi Pico
  • Other RP2040 boards should work making sure to connect appropriate pins

Build

git clone this repo and cd into it.

rake

Then you'll get build/PicoRuby-RP2040-Peripheral-Demo.uf2.

Install and run

• Install PicoRuby-RP2040-Peripheral-Demo.uf2 into RP2040
• Connect the USB serial cable to the host PC
• Open a serial terminal with values below:

  entry	value
  Baudrate	115200
  Data bits	8
  Stop bits	1
  Parity	none
  Flow control	none

• Start RP2040 by connecting a power or pushing the reset button

Usage

You can figure it out in mrblib/app.rb

COM18.-.Tera.Term.VT.2023-04-04.14-47-29.mp4

Footnotes

1. Optional. Connect if you want to supply bus power from the cable ↩

2. 3V3 also should work though, 5V would be better for the reliability of switching over from battery ↩