BT serial / data logging

While USB is probably the fastest logging option, CurrentRanger also has a serial header where you can connect a wireless HC-06 BT serial device, this header will output serial data in the following format when a is detected (detection is done during power-ON, see below):

123E-x – followed by newline, where x is the range (3=mA, 6=uA, 9=nA). Example: 2345E-3 is scientific notation for 2345mA.

Upon startup, the CR executes an “AT” command query to this bluetooth serial header, if it receives an “OK” response back within one second timeframe, then it will automatically start logging the sampled values to this serial header. If does this check 2 ways, with and without line ending (crlf characters). This has been confirmed to work with generic HC-06 bluetooth modules that implement the AT command interface.

The HC-06 Bluetooth module is recommended since it’s pretty commonly available and relatively easy to use. It usually comes set to 19200/115200 baud. The default CurrentRanger firmware serial header baud is set to 230400, so you need to match this baud in the HC-06 module using the AT command set (by issuing the AT+BAUD9 command), see this link for more details.
It is reported that the new HC-06 modules (flashed June 2017 and later (get firmware version via AT+VERSION) have a different behavior: 9600baud default speed and both NL & CR are required. To change port speed issue command AT+UART:230400,0,0.

Here’s a sample capture of a RaspberryPi booting up, captured on the Arduino IDE’s serial plotter (mA range):

Bluetooth logging might be too slow, and USB serial logging will be much faster, but you should be sure not to create ground loops, a USB isolator is recommended, please see the Safety and Proper Usage page for details.

The Bluetooth/USB logging while using the OLED is not recommended. While possible, it will make logging slower due to OLED screen updates.