The HAMKit VMAC PiHat has a number of connections around the board, in order to interface both analogue and digital requirements.
Analogue connections, for both Audio and Video input and output, are via the RCA connectors. The DTMF analogue audio input is on a 6 way Mini JST connector (I/O 2).
Digital and control sense connections (such as GPIO, Receiver Squelch, PTT etc.), are via PCB header connectors (standard 40 way GPIO and two 6 way Mini JST).
Connections from the HAMKit VMAC PiHat to the Raspberry Pi are made via the Pi’s standard GPIO 40 pin header.
- I2C (SDA/SCL)
- UART (TXD/RXD/RTS)
- DTMF Decoder (D0/D1/D2/D3/DINT)
- LED (Status)
- PTT Out
- Squelch or control inputs (SQ1/SQ2/SQ3/SQ4)
- Button (MCLR)
- ID EEPROM (ID SDA/ID SCL)
- 5V to Pi
- 3V3 from Pi to PiHat
Warning: Do not externally supply 3v3 to the PiHat if it is connected to the Raspberry Pi via the GPIO header, as this will damage the Pi.
The 3.5mm jack socket is configured the same as the Raspberry Pi in order to give a loop-back option from the Pi to the PiHat.
Mini Header Connectors
Two small JST 6 pin SH connectors are used to easily connect to the PiHat, denoted as I/O 1 (J4) and I/O 2 (J13) respectively.
Note: Whilst these connectors are small, they are also fragile if the plug is forced in or our out of the PCB mounted socket. Support the socket with a finger when inserting or removing a plug.