ESP32-epaper-station

An E-paper shelf label (electronic shelf label or ESL) base station based on an Electronic Shelf Label and an ESP32. One tag is used as a zigbee radio to send packets to other tags/labels/esl's. It's based on the work of epaper/tag heroes listed below

Disclaimer

• By using this software you acknowledge that I am in no way liable if you burn down your PC, set your hair on fire or other potential things that may or may not happen due to the use of this software.
• THIS IS PRETTY MUCH IN ALPHA STATE RIGHT NOW - IT KINDA WORKS, BUT IT IS SOMEWHAT UNSTABLE AND VERY MUCH UNSUPPORTED -

Big thanks

• Dmitry
• ATC1441
• DanielKucera
• My incredibly patient wife & children
• The lovely people in the ATC1441 discord

Howto

You're going to need a couple of things

• ESP32 (whatever board, a minimum of two GPIO pins for a serial connection)
• Solum ZBS243 SOC-based ESL (I tried and built it for the 2.9"/1.54" board). The EPD panel can be disconnected or removed
  • ZBS_Flasher- ESP32/ESP8266/Arduino Nano based flasher for the ESL. We'll try to integrate this into the first ESP32 in the future
• Optional: Webserver running PHP
• Shelf labels running the custom firmware (originally version from dmitry)

Getting stuff up and running

• Flash the shelf label/tag with the binary provided in the firmware_zigbee_base directory. Guides to flash label can be found here
• Make sure to enter a valid mac address on the infopage 0x10 offset (8 bytes) and write it back to the tag
• Open the ESP32 firmware and edit settings.h, make sure your webserver is filled in correctly.
• Build the ESP32 firmware and flash to your ESP32 board. I like to use PlatformIO. Whatever works for you!
• Connect the base-station-ESL to the ESP32 using the designated pins. Pin configuration can be changed in serial.cpp!
• Connect the ESL VCC and ground pins to the ESP32. Make sure to hook it up to 3.3v [optional]
• Add the wwwdir folder to your webserver, rename to esl or whatever you've entered in settings.h
• Write access to the 'img' directory is needed
• Boot the ESP32 and use WifiManager/config portal to connect the ESP32 to your network

Next steps / errata

Omg where to start... It's unstable, only happy flow is implemented, there is almost 0 error handling. These tags aren't meant to be used as base stations, the radio interface may be unstable and can stop/drop out. Your milage may vary, and is very much dependent on network congestion and RF environment.

When connected to a valid board, it'll automatically flash it and set the correct mac address. Very little to do!

Connect to it's ip adres using http://<ip?>/edit and add image files to display there!

Todo

• Improve radio latency/speed
• Built-in flasher
• Error handling
• Web interface
• Improved PHP side - database for tags?
• Remove crypto from both custom firmware/ESP32 should improve speed
• Use the display of an ESL as a base-station status screen
• Wifi stability
• Code clean-up
• ...

FAQ

• Q: OMG Your code is a hot mess / unmitigated dumpster fire / whatever

  • A: Yeah I know. This isn't my day gig, feel free to clean it up and hit me up with a PR

• Q: Can the base-station run on microcontroller board X

  • A: Maybe. Feel free to port it and hit me up with a PR when you do. I wouldn't recommend it per-se, ESP32's are cheap and highly effective for something like this

• Q: Does this work for other labels/tags?

  • A: Not that I'm aware of. They need to be running custom firmware anyway; this base station currently uses dmitry-style communication with tags

• Q: Can you help me build this?

  • A: Sorry, no. My time is very much limited. If you can't figure this out on your own, you are probably not the intended audience. Once again, sorry.

• Q: When will X be done?

  • A: Maybe tomorrow, maybe never