Connecting Tetra Radio:
Example of Connecting the MTM800e to the Pi
To connect the MTM800e to the Pi, you’re going to need to follow the following wiring guide to connect up the 3.3v FTDI cable for PEI data, and your chosen Sound Card (Signalink, or R1 2020)
Radio Pins (MTM800e)
The below diagram is of the rear of the MTM800e, with the rear of the radio facing you.
Note the location of pin 1.
1. PEI Data Connectivity:
Using 3.3V FTDI Cable
– Use FTDI cable to connect pins : 8 (Ground), 17 (CTS), 19 (RXD), and 20 (TXD) to the MTM800e
2. Sound Card Connectivity:
– For Signalink: Connect PTT, Mic, Speaker, and Group pins to the MTM800e
If you’re using a Signalink as your soundcard, use the below pin guide.
Note that the below guide assumes that you’ve directly mapped the PTT, Mic, Speaker and Group pins from the A side to the B side inside the Signalink (this is not done by default).
– For R1 2020: Connect RX Audio, Ground, PTT, and TX Audio to the MTM800e
If you’re using the R1 2020 soundcard (blue box), use the below diagram and pin guide to connect the soundcard to the MTM800e.
Note the pins are numbered right to left on the 26 pin connector that comes with the R1 2020 soundcard, so long as you’re holding the connector with the pin holes facing you, and the DIN connector is facing upwards and away from you.
Programming the Gateway Radio:
Basic Radio Programming guides has been already published Here