How to Use Pi Hat with a Serial Adapter
Use Pi Hat with a serial adapter
Please be careful if using a serial adapter to communicate with the Pi Hat. A wrongly wired Pin may damage the Pi Hat which will of course void any warranty.
The MDB Pi Hat is specifically designed to be assembled on the Raspberry Pi, but it can also be controlled by other serial adapters (like USB-Serial, RS232 3.3V TTL) as a standard serial device.
Some Considerations:
- Besides a custom Cable or similar connection, it is necessary to have 3.3V (which will be used to power the Pi Hat Microcontroller) and the 5V (used for MDB Signals) available to the Pi.
- If the Pi Hat is powered from MDB, the 5V are already available and do not need to be provided through the 40 Pin header, otherwise, it needs to be connected there.
- The serial connection configuration (parity, baudrate, etc...) should be the same as described in First Steps - UART.
- To Ensure stable operation, please provide power (3.3 V) to both pins 1 and 17 and ensure that all GND pins are connected to GND of the power source.
Wiring
Below is a detail from the schematic, where you can see which pins are connected and which ones are not (this makes sense for those who want to connect the Pi Hat on a non-pi hardware, or for example with an external USB-Serial cable).
The wiring should be as follows:
- Connect the Serial adapter's TX Pin to Pin 8
- Connect the Serial adapter's RX Pin to Pin 10
- Connect 3v3 to pins 1 and 17
- Connect GND to pins 9,25,39,6,14,2030 and 34
- If not powering the hat through MDB, connect 5V to pins 2 and 4
Schematic of the 40 pin header of the Pi Hat:
nReset is GPIO6 of the Raspberry Pi, this pin is used to reset the Pi Hat's microprocessor. While Low, the microprocessor will be off.