QTFM Gen-2 Standard Comms Board

QTFM Gen-2 Standard Comms Board

Every QTFM Gen-2 sensor comes with a standard comms board (SCB). The SCB is a bridge to connect the QTFM Gen-2 to a PC using a USB port. We recommend the user test the sensor with the SCB before field deployment. On the standard comms board,

  1. a USB-UART bridge transmits raw UART signals from the sensor electronics (ECU) to a PC over a virtual COM port
  2. an onboard switching regulator upconverts +5V from USB to +10V required by the ECU
  3. supercapacitors clean up and stabilize the USB voltage
  4. access to sync in/out, mag data pulse (MDP), and raw UART

Electronic Schematic

Standard Comms Board with labels

Connecting the SCB
15-pin FPC connector: Connect the flex cable from the sensor electronics (ECU) to the 15-pin FPC connector on the SCB
USB Cable/type A to micro-B: Plug one end into the SCB and the other end into the PC

SCB has a UART bridge that will create a virtual COM port on the PC when plugged in. The new virtual COM port that is created can be seen in the device manager

Sync out (UMCC connector, output): 1 kHz, 3.3V square wave. The falling edge denotes the magnetic field measurement start time. Connecting sync out from the master sensor to the sync in of the slave sensor ensures the master and slave sensors are perfectly synchronized and make magnetic field measurements at the same instant

Sync in (UMCC connector, input): Accepts 1 kHz, 3.3V square wave to synchronize two or more QTFM Gen-2 sensors

Mag Data Pulse (MDP): 3.3V output pulse. MDP will stay low until the sensor has completed its AutoStart. The rising edge of MDP can be used to jitter-free timestamp magnetometer data (1 pulse for each data sample that is printed)

Extl +10V/GND: The sensor can be powered with an external +10V power supply using these pins, instead of the +5v to +10v switching regulator onboard the SBC. Please be sure to remove R48 circled in green

Included with every sensor.