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?

Via tindie (if sold out DM via Twitter, I might have a few left ;))

Building, Flashing and Frameworks

Via Makefile and DFU (C, C++)

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

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 Nodate (野点) (C++, Ada)

https://github.com/MayaPosch/Nodate

Rust

Thank you @jamesmunns! :3

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

Schematic

HW v1.2/OtterPill.pdf

Pinout

Pinout by SarahhhhFoster :)

Examples and projects

Blink example firmware

Blink/

STM workshop based on OtterPill

https://github.com/Jana-Marie/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/Jana-Marie/USB-PD-Firmware

IBM dials retrofit

https://github.com/Jana-Marie/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) -> Added series resistor to reduce ringing
• Remove R8, R9
• Redraw the FUSB302B Symbol -> forgot why, works great
• Consider switching to STUSB4500 (Easier PD requesting, same price) -> FUSB works great, no need to change
• Add VBUS ADC

Special thanks

@jamesmunns for creating the Rust examples.

@MayaPosch for creating the Nodate framework and adding the OtterPill.

@ansemjo for creating a PlatformIO configuration.

@SarahhhhFoster for creating the awesome pinout diagram.

Images

Rev 1.2

License

Copyright Jana Marie Hemsing 2023.

This source describes Open Hardware and is licensed under the CERN-OHL-S v2.

You may redistribute and modify this source and make products using it under the terms of the CERN-OHL-S v2 (https://ohwr.org/cern_ohl_s_v2.txt).

This source is distributed WITHOUT ANY EXPRESS OR IMPLIED WARRANTY, INCLUDING OF MERCHANTABILITY, SATISFACTORY QUALITY AND FITNESS FOR A PARTICULAR PURPOSE. Please see the CERN-OHL-S v2 for applicable conditions.

Source location: https://github.com/Jana-Marie/OtterPill

As per CERN-OHL-S v2 section 4, should You produce hardware based on this source, You must where practicable maintain the Source Location visible on the external case of the Gizmo or other products you make using this source.