I’m new here. i have a MT300N-V2 in the mail. I am reading up and getting ready to do some simple hardware hacking.

The web site says “4 GPIOs for more DIY fun”. I have found the PCB pinout of the header showing:

  • GPIO13 = RX0
  • GPIO12 = TX0
  • GPIO4 = I2C_SCLK
  • GPIO5 = I2C_SD
  • GPIO45 = TX1
  • GPIO46 = RX1

Which of the pins are available. I want to hook up a GPS module TX and RX to a 3.3V UART and the GPS PPS signal to an interrupt-driven GPIO input.

I intend building a Stratum 1 NTP reference clock. I have just made one using a Raspberry Pi Zero W. It is better than internet NTP servers, but the jitter on the wireless interface is larger than I like