Cyberdeck Chat

The Meshberry is a mesh chat app for the CYD + M5Stack CardKB v1.1, built for The Hmm cyberdeck workshop. Devices in range talk to each other over ESP-NOW, and forward messages for other users. When not in range of other users, the device can be used for Note taking and as a Bluetooth keybaord.

All the mesh chat functionality was directly ported from https://github.com/7h30th3r0n3/Evil-M5Project/wiki/EvilChatMesh

Hardware

• Board: We used a non-standard CYD variant; [1005008564907457] from Aliexpress, mostly for the price and USB-C connector. The peripheral connectors are placed a little differently from the commonly documented ESP32-2432S028R. The pin configuration in this project is specific to this board and may not work on other CYD revisions without changes to the GPIO assignments.

ESP32-32E/ESP32-D0WD-V3, no PSRAM, 320×240 ST7789 display, resistive touch.

• Keyboard: M5Stack CardKB v1.1, wired to the board's 1.25 mm peripheral headers (GPIO23/19) over I2C. 3.3V and GND are available on the other header, so a custom cable is needed. See include/config.h for pin assignments. The keyboard uses pins IO19 and IO23 for I2C, which are also wired to the SD card SPI pins. So no SD card support regrettably.

Build & flash

I've used PIOArduino for building, but regular PIO should work fine. The source can be found in /src. src/meshberry hold the source for the chat / notes applciuation src/chat-relay is a slightly modified version of https://github.com/7h30th3r0n3/Evil-M5Project/blob/main/slave/EvilChatMesh-Relay.ino with the callback functions modified for the new signatures. Upload this to a 'regular' ESP32 module/devkit to extend your mesh chat network.

pio run --target upload

Upload LittleFS data/config.txt. This deletes whats already there, so existing notes etc are lost.

pio run --target uploadfs

config.txt reference

All values have hardcoded defaults, so any key can be left out entirely.

Key	Meaning
nick	Set nickname. Max 15 characters, no spaces. /nick <name> in the app also updates this.
brightness	Backlight, 0 (off) - 255 (max). Default 200
snd_msg_freq, snd_msg_ms	Frequency and duration (ms) of the incoming-message beep.
snd_sys_freq, snd_sys_ms	Frequency and duration (ms) of the join/leave beep.
touch_threshold	Threshold for touch to wake on Touch7 pin. Higher = easier to trigger. Not recommended for now.
color_*	6-digit hex RGB (no #), same format as CSS, e.g. ff0000 is red. See the table below for which UI element each one controls.

Color key	Controls
color_bg	Screen background
color_header_bg	Header and Footer bar background
color_msg	Message body text
color_nick_other	Nickname color for other people's messages
color_nick_own	Nickname color for your own messages
color_system	System messages (joins, nick changes, errors)
color_input_prompt	The > prompt on the input line

Colors can also be changed from the device itself with /set <key> <hex> (e.g. /set color_bg ff0000), see below.

Chat commands

Typed into the input line, same as any chat message:

Command	Effect
/nick <name>	Change your nickname (saved to config.txt)
/me <action>	Roleplay-style action message
/people	List currently connected peers
/clear	Clear the chat window
/clearnotes	Erase all saved notes
/set <color_key> <hex>	Change a color setting; saved to config.txt, visible after sleep/restart
/bt	Toggle BT send mode (see below)
/sleep	Put the device to deep sleep (wake via BOOT button or touch7)
/help	List commands on-device

Notes mode

Press Tab to switch between chat and the notepad. What you type in notes mode is saved to a file on the device instead of broadcast on the chat.

BT mode

Your cyberdeck can also act as a Bluetooth keyboard. To activate BT mode, Type /bt on your deck. The device is visible as Bluetooth HID device with your nickname as the device name.

This has two functions:

1. Use it as a keyboard to remote control your computer / phone / tv etc.
2. It can type out the notes you stored in Notes-mode automatically into whatever text area you have open on your device. To activate this press the FN key, then press ESC.

MAKE SURE YOU HAVE A TEXT EDITOR (NOTES, AN EMAIL) OPEN BEFORE YOU ACTIVATE THIS.

Press TAB exits BT mode and brings you back to the chat.

Notes are not cleared automatically after sending, use /clearnotes when you're done with them.