5. Zone Expansion Board
To connect a zone expansion board, use the extension cable you received to
link the OSPi’s OUT port to the expansion board’s IN port. The connector on the
cable is polarized (with a bump on the top), so there is only one way to plug it.
If you have multiple expansion boards, you can daisy chain them in the same
way, by following the OUT -> IN links.
When using zone expansion boards, the sprinkler valves are wired the same
way as before: one wire from each valve should come together and go to the
COM terminal on the OSPi; and the other wire from each valve goes to an
individual station terminal.
6. Rain Sensor / Flow Sensor / Program Switch
If you have a
, you can connect it to OSPi via the rain sensor terminal. The rain sensor has two wires and is
essentially a rain-activated switch. The OSPi software can decide what to do when rain is detected, such as turn off
stations or ignore rain. The latest OpenSprinkler also supports using the sensor terminal to connect a flow sensor, or
program switch. Please refer to the
Sensors Section for details.
7. Analog-Digital Converter (Advanced Topic)
OSPi has a built-in PCF8591T A/D D/A converter, which provides four 8-bit analog inputs, and one analog output. The
analog inputs can be used to read analog sensors, such as light, temperature, soil humidity. Details on how to use this
converter can be found in this
.
8. Radio Frequency (RF) Transmitter (Advanced Topic)
The current OSPi has a 3-pin header that fits a 433MHz or 315MHz radio frequency (RF) transmitter. This allows you to
use OSPi to communicate with RF wireless power sockets. Please refer to the
RF Transmitter
Section for details.
