Mesh Station 24b

WROOM-32

Mesh Station 2024 Model B (MS24b) is an ultra low-cost computer with headers for expandability.

MS24.2 is implemented with the NodeMCU ESP32 and its clones (board: nodemcu-32s).

This model is similar to the official Espressif ESP32-DevKitC.

Using the esp32-wroom-32 module with 2 rows of 19-pin headers.

  1. NodeMCU Language Reference Manual - NodeMCU Documentation
  2. https://esphome.io/devices/nodemcu_esp32.html

1. Pin-outs

source: mischianti

2. Buttons

There are 2 on-board buttons marked EN and BOOT.

  1. EN button is connected to ENABLE pin and is normally pulled high, to restart the station just pull it low by grounding it to reset the device.

  2. BOOT button is connected to GPIO0 and is normally pulled high. It can be used as an input button AFTER boot up. Pressing it during boot up will interrupt the boot and put the device into firmware upload (flash) mode.

Sample script:

binary_sensor:    
  - platform: gpio
    pin: 
      number: GPIO00
      inverted: true
      mode:
        input: true
        pullup: true
    name: Boot Switch
    internal: true
    on_press:
      - voice_assistant.start:
    on_release:
      - voice_assistant.stop:

USB Interface

There are many different USB interface chips used in different WROOM-32 implementations, they are very similar in performance and reliability (e.g. CP2102, CH340 etc.) - just make sure you are NOT buying the fake ones.

References:

OLED Display

OLED display provides a low-cost high contrast screen without needing alternative light source (e.g. black lighting) when use in the dark.

1. Bluetooth Marker

A major function of MS24.2 is to function as a Bluetooth Activity Marker transmitter and receiver.

Currently MS24.2 cannot be a transmitter and receiver at the same time, so it will normally be transmitting and will change to become a receiver for about 1 minute once in a while (e.g. once a day) to perform Activity Marker attestation.