OtterPill

OtterPill is a 3$ STM32F072 devboard featuring USB 2.0 full-speed, a DFU Bootloader, a USB-PD Phy and Arduino nano alike pinout and size.

Changelog V1.2: BOM cost reduction by ~40%, PCB can be fully populated by JLCSMT, more efficient buck converter (PCB gets less warm at 20V), GND-hook for probing, Reset-Pin exposed as pad, power pads for 20V/5A

How do I get an OtterPill?I have made a small production run, OtterPills will be available soon! More details will be announced via Twitter :3

Building and Flashing

Via Arduino

You can build and flash the firmware via Arduino as described here.

Via PlatformIO

https://gist.github.com/ansemjo/ab1c12f7c78abb140f7272501aff2a55 Thank you ansemjo :3

Via Makefile and DFU

Or you can generate a basic firmware, with HAL init and Makefile, with CubeMX. The binary can then be build with make and flashed with dfu-utils. To enter DFU mode, press and hold the Button while plugging in power.

$ make
$ dfu-util -a 0 -s 0x08000000:leave -D build/firmware.bin

Schematic

HW v1.2/OtterPill.pdf

Pinout

Pinout by SarahhhhFoster :)

Blink example firmware

Blink/

Rust example

Thank you @jamesmunns! :3

https://github.com/jamesmunns/OtterPill-rs

STM workshop based on OtterPill

https://github.com/Jan--Henrik/hackerhotel-stm-workshop

USB-PD example firmware

This is a working USB-PD example using ChibiOS, a new voltage can be requested by pressing the Button.

https://github.com/Jan--Henrik/USB-PD-Firmware

IBM dials retrofit

https://github.com/Jan--Henrik/IBM-dials-retrofit

Shields and addons

Most Arduino shields should be compatible.

USB-to-CAN-adapter

Todo for HW v1.3

• Replace U1 with ESDU5V0H4
• Add a TVS Diode to VBUS (e.g. SJD12A22L01)
• Remove R8, R9
• Redraw the FUSB302B Symbol
• Consider switching to STUSB4500 (Easier PD requesting, same price)

Images

Rev 1.1

Rev 1.2