Simple Opto-Isolator board with only two channels to isolate RX and TX on UART communication lines. Both sides have FTDI style connectors but only GND, VCC and RX/TX are used. CTS and DTR are not connected. Also both sides need to have a separate power supply.
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.
1-Wire Temperature, Humidity and Light sensor uses one DS2438 1-Wire chip for three different measurements. This board is very similar to the 1-Wire Humidity and Temperature Sensor – even the board size is the same. The only difference is added BPW 35 S photodiode from Osram and the current sense resistor for light level measurements. The actual calibration (if needed) should be done in the software or by replacing the current sense resistor (default 4.7k 1%, before nov 2018 it was 240Ohm).
1-Wire device: Maxim DS2438Z+ ADC with internal 13-bit temperature sensor
Wiring on the full set model with the RJ12 plug (compatible with Maxim DS9490R USB to 1-Wire adapter):
1 – VCC 5V (yellow)
2 – NC
3 – OW 1-Wire data (green or blue)
4 – GND (red)
5 – NC
6 – NC (black or none)
Evolution of TaaraESP SHT21 Wifi humidity sensor with added pressure and light sensor. The LED and programming header work the same way as the previous model. Regulated 3.3V and GPIO2 are now available via unused pins on the programming header.
Simple M-Bus to 3.3V UART level converter for 1..3 M-Bus slave devices. Board is designed to fit into off-the-shelve Kradex Z105 DIN enclosure. The board has an on-board 5V to 34V boost converter. UART input has an optional low voltage drop diode for the ESP8266 microcontrollers that do not boot when the TX line is pulled down.
The main purpose of DS28E17 device and this board is to use i2c slave devices like sensors and low power microcontroller boards over much longer 1-Wire networks.
1-Wire Slave to i2c bridge Plug consists of DS28E17 chip, an on-board 3.3V LDO regulator and 5V to 3.3V level shifter for interfacing 3.3V DS28E17 device with 5V 1-Wire bus. There are also three optional LED indicators for debugging. The board layout is compatible with TaaraNode and JeeNode boards but can be used with any other 3.3V low power microcontroller board or i2c device.
Low cost Wifi Humidity sensor with ESP8266-7 or ESP8266-12 Wifi module and SHT21 digital humidity and temperature sensor. 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 entering 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). Programming header is standard FTDI style UART serial interface. 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.
Serial OLED is a small adapter board for cheap 128×64 0,96″ OLED i2c display module and it can be used as a serial console for microcontroller projects with 3.3V logic level. One of the four microswitches is hardwired as the reset for the Serial OLED board. Other three switches are connected to the digital pins of the on-board microcontroller. The additional FTDI connector (host) can be used to program the Serial OLED board itself.
There are two popular models of cheap 0,9″ OLED displays based on SSD1306 driver IC available on the ebay. They are slightly different size (27x27mm and 27x28mm) and the supply polarity is different. This adapter board fits both modules and the supply polarity for the OLED module can be set by the solder-jumpers.
Compatible with 27x27mm and 27x28mm 0,9″ i2c OLED modules
OLED module supply voltage polarity set by solder-jumpers