RS-485+CAN bus+DCDC Converter Shield for WeMos Mini

June 7, 2023 |   |  Comment  |  CanBus, ModBus, Wifi

RS-485 + CAN bus + DCDC Converter Shield for WeMos Mini is a small three-in-one board to fit on top of WeMos Mini (ESP32) microcontroller boards:

  • RS485 to TTL Serial transceiver with automatic flow control connects UART compatible GPIO pins on the microcontroller.
  • CAN bus Transceiver is suitable for 12 V and 24 V systems and it connects to ESP32 integrated CAN controller via GPIO pins.
  • DC/DC Converter allows powering the board and the microcontroller with 3.3 V from ~12 V DC source.

This board offers an easy and compact way to connect NMEA-2000 bus and/or one NMEA-0183 (RS-485/RS-422) device to WiFi network on a small boat using NMEA2000-Gateway with ESP32 software getting power from the NMEA-2000 bus or separate ~12 V DC source like 12 V battery.

Features

  • 3.5mm screw terminals
  • Supply voltage: 12 VDC (3.8V-32V)
  • GPIO voltage: 3.3 V
  • DC/DC converter: AP63203
  • RS-485 transceiver with auto direction control: THVD1406
  • RS-485 interface connects to secondary UART on the WeMos Mini ESP32 boards
  • CAN bus transceiver: SN65HVD232
  • Optical isolation: none
  • GPIO pins for WeMos D1 Mini ESP32:
    •  RS-485
      • RX: GPIO16
      • TX: GPIO17
    • CAN bus
      • RX: GPIO19
      • TX: GPIO18

Resources

Buy

  • Bare PCB: 3€
  • Pre-assembled: 21€

RS-485 Shield for WeMos D1 Mini

March 21, 2023 |   |  Comment  |  ModBus, Wifi

RS-485 Shield for WeMos D1 is a half-duplex RS-485 to TTL Serial transceiver board for WeMos D1 Mini (ESP8266) and WeMos C3 Mini (ESP32) microcontrollers. This board was designed mainly for easy Wifi to Modbus connectivity using HomeAssistant‘s ESPHome Modbus Component.

Features

  • RS-485 chip: MaxLinear SP3485 or any other pin compatible RS-485 to TTL serial transceiver
  • RS-485 connector: RJ45 or 3.5mm 3-pin screw terminal
  • Supply voltage: 3.3V
  • Logic level: 3.3V
  • Serial interface connects directly to UART interface on the microcontroller (Serial debug should be disabled)
  • Esphome pins on WeMos D1 Mini (ESP8266) boards:
    • TX: 1
    • RX: 3
    • Flow control: 2
  • Esphome pins on WeMos C3 Mini (ESP32) boards:
    • TX: 21
    • RX: 20
    • Flow control: 6

Resources

Buy

  • Bare PCB: 3€
  • Pre-assembled: 12€

TaaraESP SHT21 USB Wifi Temperature and Humidity sensor

August 20, 2021 |   |  Comment  |  Wifi

Next version of the Wifi Temperature and Humidity sensor with ESP8266 ESP-12S Wifi module and SHT21 digital humidity and temperature sensor with additional USB interface. The board has on-board 3.3V regulator and can be powered from USB charger with USB-A socket. Deep sleep function is supported for ultra low power mode. There are also an on-board status LED and a PROG button for entering the program mode (hold down while power-up). The board is now equipped with the serial to USB converter chip to make flashing and monitoring the sensor more convenient. Temperature and Humidity sensor is located away from other components and separated with cut out slot for better thermal isolation. The board dimensions are designed to fit the off-the-shelf enclosure.

Features:

  • Wifi module: ESP8266 ESP-12S
  • Digital humidity and temperature sensor: SHT21 or HTU21D
  • Supply voltage: 5V
  • USB serial interface: CH330N
  • Only TX/RX serial signals are connected to USB
  • DTR signal is not connected to USB
  • Program button
  • Status LED
  • Deep sleep function: supported
  • Home Assistant integration: ESPHome
  • Pins
    • LED: 13
    • SDA: 4
    • SCL: 5
  • Optional enclosure: Multicomp 1603603

Resources

Buy

  • Bare PCB: 3€ 
  • Pre-assembled: 37€
  • Full set 42€ 

1-Wire Shield for WeMos D1

April 22, 2018 |   |  Comment  |  1-Wire, Wifi

1-Wire Shield for WeMos D1 is 1-Wire to i2c bus converter board based on Maxim DS2482-100 Single-Channel 1-Wire Bus Master chip. It is used to off-load the time critical 1-Wire waveform generation from the MCU to the 1-Wire Bus Master to achieve error free operation with longer 1-Wire bus situations. Board header layout is compatible with WeMos D1 mini microcontroller boards. There is on-board strong pull-up mosfet and the level converter for 5V to 3.3V i2c interface.

Features

  • 1-Wire device: Maxim DS2482-100 Single-Channel 1-Wire Master
  • 1-Wire connector: RJ45 (RJ12 or 3-pin 3.5mm screw terminal on request)
  • Supply voltage: 5V from WeMos D1 board
  • i2c logic level: 3.3V
  • 1-Wire logic level: 5V
  • Strong pull-up capability

Resources

Credits

Buy

  • Bare PCB: 3€ 
  • Pre-assembled: 17€

 

ESP8266 DHT22 Wifi Humidity sensor

January 27, 2015 |   |  Comment  |  Wifi

Low cost Wifi Humidity sensor with ESP8266 Wifi module and DHT22 digital humidity and temperature sensor. The board has on-board 3.3V regulator and can be powered from USB charger with USB-A socket. All the pins of the wifi module have broken out to breadboard-friendly 0,1″ headers. Unused pin is connected to 5V input for easier progamming. There is also LED and a button for entering the program mode (hold down while power-up) which makes this board suitable for prototyping and developing apps for ESP8266 Wifi module. When the Wifi module is constantly in full operational mode (with HTTP server etc.) it gets quite warm and can affect the temperature and humidity readings. Keeping the sensor 3-4mm away from the board and/or putting the module in sleep will resolve this problem.

Features:

  • Wifi module: ESP8266-03
  • Digital humidity and temperature sensor: DHT22
  • Supply voltage: 5V
  • Program button
  • Status LED

Resources

Buy

  • Bare PCB: 3€