TaaraLabs – Page 2 – Opensource Hardware and Software projects around the house.

M-Bus UART converter

October 30, 2015 | ull | 2 Comments | M-Bus

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.

Features

M-Bus voltage: 34 V
M-Bus slaves: 1..3
UART level: 3.3 V
UART connector: 3.5mm screw terminal
Supply voltage: 5 VDC
Fuse: 500mA @ 6V
Short circuit protection: none
Single layer PCB
Dimensions: 86x14mm
Board fits into Kradex Z105 DIN enclosure

Resources

Buy

Bare PCB: 3€
Pre-assembled: 25€
Pre-assembled with terminals: 30€
Pre-assembled with terminals and DIN enclosure: 35€

: Pre-assembled

: Schematic

: Pre-assembled with terminals

: Board layout

: PCB

1-Wire Slave i2c bridge Plug

October 19, 2015 | ull | Comment | 1-Wire, TaaraNode

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.

Features

1-Wire Slave to i2c bridge device: DS28E17
Supply voltage: 5V from 1-Wire bus
1-Wire logic level: 5V
i2c logic level: 3.3V
On-board 3.3V regulator
LED indicators: BUSY, ED (Error Detected) and XD (Expecting Data)
Headers: 0,1″
1-Wire connector: RJ45 or RJ12

Resources

Buy

Bare PCB: 3€

Pre-assembled: 20€

: Schematic

: Board layout

: PCB

: Pre-assembled

TaaraESP SHT21 Wifi Humidity sensor

October 13, 2015 | ull | Comment | Wifi

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.

Features:

Wifi module: ESP8266-7 or ESP8266-12
Digital humidity and temperature sensor: SHT21 or HTU21D
Supply voltage: 5V
FTDI 0.1″ locking header for programming and debugging
UART logic level: 3.3V
Program button
Status LED
Deep sleep function: supported
Pins
- LED: 13
- SDA: 2
- SCL: 14
Optional enclosure: Multicomp 1603603

Resources

Buy

Bare PCB: 3€

: Schematic

: Board layout

: PCB

: Pre-assembled

: Full set

Serial OLED

February 25, 2015 | ull | Comment | Tools

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.

Features

Compatible with 27x27mm and 27x28mm 0,9″ i2c OLED modules
OLED module supply voltage polarity set by solder-jumpers
Onboard Atmega-328p microcontroller
Logic level: 3.3V
Supply voltage: 5V
Reset switch
User assignable switches: 3

Resources

Design files on GitHub

Buy

Bare PCB: 3€

: Board layout

: Schematic

: PCB

: Serial OLED

: Full Set

FTDI Micro

February 1, 2015 | ull | Comment | Tools

FTDI Micro is simple USB to UART serial adapter based on FT232R chip. The board is pre-configured for 3.3V logic level but with the solder-jumper can be set to 5V logic level as well.

Features

Micro USB socket
USB UART interface chip: FT232R
Logic level: 3.3V default, 5V optional
USB port protection with polyfuse
TX LED: Red
RX LED: Green

Resources

Design files on GitHub

Buy

Bare PCB: 3€

: FTDI Micro

: FTDI Micro PCB

: Schematic

: Board layout

LCD Plug

February 1, 2015 | ull | 1 Comment | TaaraNode

LCD Plug is TaaraNode and JeeNode compatible i2c driver board for HD44780 based 16-pin LCD displays. This board is based on JeeLabs LCD Plug with additional Port header.

Features

Compatible with HD44780 based LCD displays
Interface chip: MCP23008 8-bit port expander
Default logic level: 3.3V
Optional logic level: 5V
Software controlled backlight: on/off

Resources

Design files on GitHub

Credits

JeeLabs LCD Plug

Buy

Bare PCB: 3€

: Schematic

: Board layout

: PCB

RTD Plug

February 1, 2015 | ull | Comment | TaaraNode

RTD Plug is TaaraNode and JeeNode compatible MAX31865 based SPI inferface board for PT100/PT1000 temperature sensors.

Features

RTD to Digital converter: MAX31865
Compatible with 2-, 3-, and 4-wire Sensor Connections
Interface: SPI
Supported sensors: PT100 (PT1000 option)
Supply voltage: 3.3V
Headers: 0.1″

Resources

Design files on GitHub

Credits

Playing With Fusion MAX31865 PT-100 RTD to Digital Breakout

Buy

Bare PCB: 3€

Pre-assembled: 24€

: Schematic

: Board layout

: PCB

: Pre-assembled

ESP8266 DHT22 Wifi Humidity sensor

January 27, 2015 | ull | 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€

: Schematic

: Board layout

: PCB

TaaraNode Mini

January 22, 2015 | ull | 1 Comment | TaaraNode

TaaraNode Mini is small Arduino software compatible microcontroller board with on-board RFM12b radio transceiver. TaaraNode Mini is very similar to the JeeNode but is much shorter and has an option to power it from CR2032 coin-cell battery.

Features

Microcontroller: Atmega 328P
Radio transceiver: RFM12b (868Mhz/433Mhz/915Mhz)
Serial interface: FTDI (3,3v logic level)
SPI/ISP header: yes
JeeNode style ports: 2
Supply voltage: 5-16V DC
Clock speed: 3.3V/16Mhz or 3V/8Mhz internal oscillator

Resources

Design files on GitHub

Buy

Bare PCB: 3€

: TaaraNode Mini

: Battery mode

: CR2032 Battery

: PCB

: Schematic

: Board layout

Ethernet Plug

January 22, 2015 | ull | Comment | TaaraNode

Ethernet Plug is small ENC28J60 based Ethernet controller board for TaaraNode and JeeNode microcontroller boards. Ethernet Plug operates entirely on 3.3V and has a on-board LDO regulator or DC/DC converter. The board can be powered either from microcontroller board it is attached to or via Passive POE. If the DC polarity from the PPOE may be issue there is also place for bridge rectifier which is bridged by default.

Features