Load Cell connected to an Arduino
Some applications may require a load cell or force sensor to input force measurement into a microcontroller such as the Arduino compatible Mega 2560. For such applications, you can use one of the following solutions:
1) Use our iLoad series digital load cells with Serial TTL (UART) output (before the S2U Serial to USB dongle that converts the serial signal into USB)
or
2) Use a resistive load cell with our DI-100U digital load cell interface with Serial TTL (or UART) output (before the S2U Serial to USB dongle that converts the serial signal into USB)
The iLoad, iLoad TR, iLoad Pro sensors as well as any resistive load cell conected to a DI-100U - have built-in, royalty free ASCII command set. One can connect the Tx, Rx serial pins from the sensor or the DI-100U directly into the Arduino Rx, Tx pins. Once connected, the microcontroller can issue commands to Tare (zero) the load cells and read raw or calibrated load/force values. You can look up the command sets available for our devices here.
Connecting Directly via Pigtail wire connections with an Arduino
Here is how to make the connections from the iLoad series digital load cells, DI-100 digital load cell interface to the Arduino Mega 2560:
Red -> 5V
Black -> Ground
Green -> Tx (out of Arduino)
White -> Rx (in to Arduino).
In our example code the Red wire from the iLoad or iLoad Pro series sensor or DI-100 is connected to the pin labeled 5V, the black wire to the pin labeled GND, the Green wire to the pin labeled TX2 (#16) and White to the pin labeled RX2 (#17). The shield wire is also connected to GND.
Connecting with an Arduino using the HX-100 Hybrid Adapter
If you want to preserve the ability to connect your sensor or interface via USB to a PC, instead of cutting off the miniB connector, you can insert an HX-100 hybrid board in between the sensor/DI-100 and the PC to get easy access to the Tx, Rx pins. You can then connect the solution either via UART/Serial TTL with your Arduino or via USB with your PC or Raspberry Pi.
Red ->VCC
Black -> Ground
Green -> Rx (into sensor)
White -> Tx (out of sensor)
Wiring Diagram
The HX-100 has a terminal block with two miniB USB connectors. You can connect the miniB to miniB cable from the iLoad/iLoad TR/iLoad Pro load cells or from the DI-100U into one end of the HX-100. You can use the second extra miniB to miniB Cable at the other end of the HX-100 to continue onto a PC for operating it as usual with our LoadVUE or SensorVUE software. In other cases, when you want to connect to an Arduino, you can simply connect the pins for 5V and Ground to the Arduino to provide power and then connect the Tx pin from the HX-100 to the Rx pin on the Arduino and the Rx pin on the HX-100 to the Tx pin on the Arduino! And presto. You'll be able to write code to access data from the sensor or interface via simple ASCII commands for ID, Units, Raw Values or for Calibrated values.
Load Cell to Arduino
If you wish to input force values from an iLoad mini load cell or any of the iLoad Series capacitive load cells into an Arduino micro controller, you can simply remove the S2U serial TTL to USB adapter and access the Tx, Rx pins via an HX-100 hybrid adapter as shown below. You can then send ASCII commands and receive force data back grom the sensor into the micro-controller.
Remove the S2U Serial to USB Adapter from the output side of the cable
Connect the cable to the HX-100 Adapter to access the Tx, Rx pins
Connect the Tx from the load cell/interface to the Rx pin on the Arduino and the Rx from load cell/interface to the Tx pin on the Arduino
Sample Code for An Arduino Mega 2560
You can download sample code for an Arduino compatible Mega 2560 microcontroller board to read weights from a scale built using a single point load cell (RSP1) and a DI-100 digital load cell interface is available here.
