Alternative Arduino Communication Methods

If a direct USB/serial connection to the in-box arduino is not possible, it is also possible to connect to the arduino over a TCP/IP socket. There are various ways to do this, but one way that has been verified to work with the box is to use an Ethernet to serial bridge, running on a device like a Raspberry Pi.

When using the box in such a manner, the Pi will need to be powered off of the battery pack in addition to the transducers. The arduino is then connected over USB to the Pi instead of to the host computer, and the Pi is connected to the host computer via an Ethernet cable (it is possible to also use a wireless connection, with both the Pi and the host computer on the same network). On the Pi, install and configure ser2net, the program which will act as the Ethernet/serial bridge. The contents of any TCP/IP packet send to the Pi on the listening port will be forwarded over the serial interface to the arduino, and vice versa for any packets sent over serial by the arduino.

One important thing to note about ser2net is that it will initiate a hardware reset of the arduino whenever a client connects to the TCP/IP socket on the Pi.

When connecting to the box in RCI, make sure to change the interface type from Serial Port to TCP Socket, place it in client mode, type in the IP address and port of the Pi, and connect as usual.

Calibration

Transducer Calibration

The transducers on RAND-E work by outputting a voltage that is linearly proportional to the pressure measured by the transducer. Therefore, to calibrate a transducer, you simply need to perform a line fit with at least 2 data points.

The easiest way to perform such a fit is by finding the output voltage at 0 PSI, then at some other known pressure. From there, any standard line fit equation will work.

Load Cell Calibration

Hi aleph please help