Many off-the-shelf devices are powered with ESP8285 or ESP8266 chips, in devices with white-label firmware provided by a company called Tuya. The project tuya-convert exists to hack these devices and enable us to load custom firmware.

Firmware options include:

• Tasmota - the original; many devices are known and pin configurations listed here
• Espurna - an alternative which has a nice Web UI and is easily configurable with custom builds
• ESP Home - a versetile firmware which supports a lot of different chips in practice, and has many great features for the advanced user

I use ESP Home both for NodeMCU type ESP8266 boards, and for off-the-shelf devices running Tuya.

How to flash a device with this repo.

0. Extract the ID for the above table using make flash
1. Configure a custom image using the esphome templates
2. Build the custom image
3. Ensure device appears on wifi network
4. Update "My Devices" table in this README.md
5. Setup esphome config and re-flash to esphome

Use esphome templating to create a template for the device. Ensure to import the _esphome.yaml package, which has the common configuration, and also the sensor packages for your use-case.

An example device YAML:

---
substitutions:
  device_id: '0fe8ed'
  device_name: 'ESP8622 Server Closet'
  static_ip: '192.168.20.63'

esp8266:
  board: nodemcuv2

packages:
  base: !include ../packages/_esphome.yaml
  dht22: !include
    file: ../packages/dht22.yaml
    vars:
      room: 'Server Closet'
      data_pin: 1

A Makefile is included to simplify the interface.

Render the template configured for device c0a4ba, and build the firmware binary:

DEVICE=c0a4ba make compile

Under the hood, this calls esphome compile command:

esphome compile templates/10945b.yaml

> esptool.py --before default_reset --after hard_reset --baud 460800 --chip esp8266 write_flash 0x0 774ba4/.pioenvs/774ba4/firmware.bin
esptool.py v2.8
Serial port /dev/ttyUSB0
Connecting....
Detecting chip type... ESP8266
Chip is ESP8266EX
Features: WiFi
Crystal is 26MHz
MAC: 84:f3:eb:c0:a4:b4
Uploading stub...
Running stub...
Stub running...
Configuring flash size...
Compressed 433552 bytes to 315828...
Wrote 433552 bytes (315828 compressed) at 0x00000000 in 28.8 seconds (effective 120.5 kbit/s)...
Hash of data verified.

Leaving...
Hard resetting via RTS pin...

Once a device has been flashed to ESP Home, one can update directly from the CLI via OTA on the network. If that is failing, switch to flash via USB.

DEVICE=c0a4ba make upload

Notes on devices to use with ESP32/ESP8266.

• ESPHome component
• ESPHome template

Pin configuration for an OLED 128x64 display. These can run on either i2c or SPI bus; this configuration uses i2c.

From the screen-side, pins left-to-right:

1. Data - i2c data pin, or SPI MOSI
2. Clk - SPI clock
3. SA0 - Select Address / Data Command (aka DC)
4. Rst - Reset
5. CS - SPI chip select
6. 3v3 - 3.3v input
7. Vin
8. Gnd

Required pin config from the ST7735 esphome.io doc:

spi:
  clk_pin: 25
  mosi_pin: 26

display:
  - platform: st7735
    reset_pin: 21
    cs_pin: 22
    dc_pin: 23

st7735.tmpl

ST7735 display driver configuration, for use with a TZT 1.8" TFT 160x128 display.

From the screen-side, pins left-to-right:

1. LED - Connect to 3v or 5v
2. SCK - SPI clock (aka CLK)
3. SDA - Bus input (aka SPI MOSI)
4. A0 - Address Select / Data Command (aka DC)
5. RESET
6. CS
7. GND
8. VCC

Required pin config from the ST7735 esphome.io doc:

spi:
  clk_pin: 25
  mosi_pin: 26

display:
  - platform: st7735
    reset_pin: 21
    cs_pin: 22
    dc_pin: 23

Infrared

The Wemos IR shield is transmitter and receiver in one convenient board. It also has an LED to show when IR signals are being sent.

The LOLIN D32 Pro has a TFT connector, as does the I2C/TFT hat. The pinout for this connector follows. The colours correspond to the 10 pin TFT connector cable that fits the LOLIN.

ds18b20.tmpl

Dallas 1-wire protocol temperature sensors, such as the DS18B20.

These are fast to read, and are fully enclosed and therefore safe outdoors.

Many sensors can be put on the same data line (hence "1-wire protocol"); each device is identified by a hexidecimal address, which esphome will print on startup when it scans the Dallas bus.

For indoors usage, the DHT22 is preferred as no circuit is required - the DHT22 pins attach directly the ESP board. The exception is the Raspberry Pi - DHT22 support is terrible (the Adafruit libraries), so preference is to use the w1thermsensor project as in mafrosis/w1therm.

┌──────────────────┐
│ DS18B20          │
│                  │
│ RED YELLOW BLACK │
└──────────────────┘
   │    │     │
   │    │     │
   │    │     │
┌─────────┐   │
│ 2.2k R  │   └┐
└─────────┘    │
   │    │      │
   │    │      │
   │    │      │

  3V    D5    GND

mosquitto_pub -h 192.168.1.198 -m 'ON' -t 707a3c/ota_mode -r

mitsubishiheatpump.tmpl

The SwiCago/HeatPump project made it possible to control Mitsubishi aircon units via serial, on a connector named CN105. A kind soul wrapped this library in esphome, as found at geoffdavis/esphome-mitsubishiheatpump.

This usage of the library has been done with the ESP8266 Wemos D1 mini v3.1 as the control board.

Wiring per the demo circuit:

┌────────┐              ┌───────────┐
│ CN105  │              │ Wemos D1  │
│        ├─┐            │           │
│ 1  12V │x│     ┌──────┤ 5V    3V3 │
│ 2  GND │-├─────┼──────┤ GND    D8 │
│ 3  5V  │-├─────┘      │ D4     D7 │
│ 4  TX  │-├─────┐      │ D3     D6 │
│ 5  RX  │-├───┐ │      │ D2     D5 │
│        ├─┘   │ │      │ D1     D0 │
│        │     │ └──────┤ RX     A0 │
└────────┘     └────────┤ TX    RST │
                        │           │
                        └───────────┘
GND  black   brown
5V   yellow  red
TX   green   orange
RX   blue    yellow