PCB preview top
PCB preview bottom
Stencil preview top
Stencil preview bottom

Readme

Inspired by article Ausdauernde Infotafel from German computer magazine c't. Kicad sources are on github as are example arduino and server software.

Notes

Input voltage is connected to a voltage regulator jack and directly to Pin6/IO34/ADC6 for monitoring. Hence input voltage must be below 3.6V. I use 2xAAA eneloop together with a step up regulator. Additionally I connected a pad for Pin8/IO32/ADC4/TOUCH9. Haven't used it yet. Maybe for a touch wakeup or status LED.

Display connector pin assignment is identical to the Waveshare hat connector.

Components needed in addition to PCB and Precious Parts:

  • ESP-WROOM-32 (or footprint compatible)
  • 3.3V Power regulator or other 3.3V source
  • Waveshare E-Ink display.
  • 2x ~10kΩ pullup resistors R1+R2
  • Crimptool for JST-PH connectors
  • 3.3V capable USB-TTL adapter for programming

Programming

This is a minimalistic board to save power. No USB included. So you need an USB-TTL adapter that is capable of doing 3.3V. This one works for me under Linux.

To upload an arduino sketch/flash firmware:

  1. Connect the USB-Adapter GND/RX/TX to the board. Most adapters need RX board/TX adapter and TX board/RX adapter. If that doesn't work try RX/RX+TX/TX. To check press the Reset button. The serial monitor must show the ESP32 boot log.

  2. Press and hold the Boot(loader) button, shortly press the Reset button, then release the Boot button. Log should show the ESP32 entering bootloader mode.

  3. Now stop any serial monitor (Arduino IDE does this automatically)

  4. Upload the sketch and wait until completion

  5. Restart serial monitor (Arduino IDE does this automatically)

  6. Again press the Reset button

Changelog

Rev A2 (minor)

  • Trace width power supply + GND
  • Via min size 0.65mm (=drill + 0.25mm)

Rev A1

  • Initial revision

Parts

Name Description
1x CONN HOUSING PH 8POS 2MM WHITE
2x SWITCH TACTILE SPST-NO 0.05A 12V
15x CONN TERM CRIMP PH 28-32AWG TIN
1x CONN HOUSING PH 2POS 2MM WHITE
1x CONN HEADER PH SIDE 8POS 2MM
1x CONN HEADER PH SIDE 2POS 2MM

Change organization, repository and project title