Raspberry Pi and Servo Hat Board
For ZAF you need to use a Raspberry Pi 3 B+ microcomputer. We used a kit to get most parts needed to operate the Raspberry Pi -- including the case. To attach the Raspberry to ZAF's frame we used velcro as described in the tubing section . To setup your Raspberry Pi please go here.
Next you will need to connect Raspberry Pi to the servo hat board . This board is called a 'hat' because it is attached on top of the Raspberry Pi and communicates with the Raspberry Pi through the GPIO connectors (here for a detailed explanation).
Your servo hat sends PWM signals to the motor controllers to control the pumps and valves. Other devices, such as the servo or safety pumps, can be directly controlled with 5V TTL lines directly from the servo hat.
Next, we describe the connections between the electronics devices and the servo hat board:
- For the wires coming from the Motor controller connect the Input 1 and 3 (IN1 & IN3) to the raw "S", for signal, on the Servo hat. And the Input 2 and 4 (IN2 & IN4)on the ground "G". You can check the details on the motor drivers page.
- For the direct connection (water sensor, servo and safety pump), connect directly voltage plus and minus and the signal "S" on the servo hat board.
