big p4ppa

A Raspberry Pi 5-channel PWM, PT100 and ADXL345 board. Should work on any Raspberry Pi 2/3/4

I was looking to add on more controllable fans to my 3D printer. The SKR was maxxed out even just a simple controllable fan, let alone PWM. Klipper supports multiple MCU's, including the Raspberry Pi so adding this to the Pi was a simple way to tackle the problem.

With a bit of spare board space (it was tight) I also fit some space to accommodate PT100 modules, so I could have a nice place to put mine.

This board is designed for low power accessories. This board is not suitable for driving high-powered loads directly.

Features

• Power the Raspberry Pi via the 5V input

You MUST power the Pi via this board. Do not connect any other power source (USB, PoE hat, battery backup hat) to the Pi when using this board.

• 5 PWM outputs (via MOSFETs with external flyback diodes)
• Independent voltages for each fan - 5V or anything up 24V
• Cutout for a 25mmx25mm fan to cool the Pi if desired
• Support for Adafruit's PT100 amplifier board OR a PT100 Stepstick (available on AliExpress/etc)
• Convenient header for an ADXL345 accelerometer to measure resonance in Klipper

For more information, please visit the GitHub page which is kept up to date! https://github.com/gcormier/bigp4ppa

Order Options

The kit requires you to solder through-hole components only, and includes:

• PCB with the SMT components (MOSFET/diodes) on rear side already soldered

• Dec 2022 The large Pi 40-pin header is now already soldered!

• Unsoldered

• 1x 40-pin Pi header
• 5x 6-pin header and 5x jumpers (for selecting voltages on the 5 fans)
• 1x 8-pin headers (ADXL345)
• 3x 8-pin female header (PT100 amp or PT100 stepstick)
• 1x 4-pin screw terminal
• 1x 10-pin screw terminal

Fully assembled means I solder on all parts.

Notes

Please check GitHub for the latest information.