README
¶
plantwaterer
Plant Waterer v2.
A robotic plant watering system in two parts.
embeddedwaterer: Tinygo program for a microcontroller that waters on a fixed schedule. watererserver: Go program for rasberryPI that communicates with the embedded application to report stat and control remotely. Currently is a standalone parser that emits CSVs with stats data.
Big Features:
- Soil humidity sensors
- Multiple relays, allows different water circuits
- Read stats / update config remotely
- Webcam for monitoring, takes snapshots
Arduino
- Turns relays on/off for specified on/off periods.
- Takes commands, sends stats back over serial.
- Monitors humidity sensors, reports back to Pi
Future Plans
- Humidity based control, water when soil dries past certain threshold
- Store customization data in EEPROM
Raspberry Pi
- Currently just records serial data to disk for later analysis
- Takes webcam snapshot every 5 minutes
Future Plans
- Simple go service, hosts website.
- Polls Arduino via serial link on some interval. Keeps state of last values to show deltas.
- If Arduino resets, Pi monitor should automatically reset the water on/off durations if they’ve been changed.
- Awair integration to pull in room humidity/temp/co2 levels
Serial Link
More details on the linux side in the pi/README.md, and the hardware side in hardware/README.md In general, standard arduino serial at 115200 baud.
3-byte header, 4-byte request
Request: CMD <command> <8bit number> <16bit number>
Response: Echo command back. Stats is special and will then send stats followed by a terminator.
Commands
| command | value | args? | Notes | |
|---|---|---|---|---|
| water_on | 0x02 | 8bit water id | Resets water timer | |
| water_off | 0x03 | 8bit water id | Resets water time | |
| set_water_on_duration | 0x04 | 8bit water id 16bit duration seconds | ||
| set_water_off_duration | 0x05 | 8bit water id 16bit duration seconds | ||
| set_next_water_at | 0x06 | 8bit sensor id 16bit value | Sets wait time to desired value. Useful after resets |
To send a command, echo over the serial link.
echo -e 'CMD\x03\x00\x00\x00' > /dev/serial0
Stats Return:
Stats are continually sent via serial every StatsIntervalSeconds, default of 5.
{"now": 1485775,
"sensors":[
{"id": 0, "d":[ 1, 37440, 2, 37376, 3, 37376, 4, 37440, 5, 37440 ]},
{"id": 1, "d":[ 1, 37376, 2, 37440, 3, 37376, 4, 37376, 5, 37376 ]}
],"sections":[
{"id": 0, "on": false, "next": 1555513, "last": 1296313,
"onTime": 50, "offTime": 259200,
"onAcc": 306, "offAcc": 1296007 }
]}
Notes:
- Number of sensors and length of history is determined at compile-time. It is limited by the memory capacity of your chip. More powerful chips can support more sensors and longer histories.
- All timestamps are relative to the local epoch, when the board was turned on.
- The data in sensors.d are pairs of (timestamp, value) from the analog input.
- onTime / offTime are current status values
- onAcc / offAcc accumulate time spent in on / off states over time
References
- https://github.com/huin/goserial
- https://www.digikey.com/product-detail/en/adafruit-industries-llc/997/1528-2003-ND/6827136
- https://tinygo.org/
- https://github.com/d2r2/go-i2c
- http://www.krekr.nl/wp-content/uploads/2013/08/Arduino-uno.pdf
- https://www.raspberrypi.org/documentation/hardware/raspberrypi/mechanical/rpi_MECH_3b_1p2.pdf
- https://www.youtube.com/watch?v=ioSYlxHlYdI (For solenoid board design)
- https://jlcpcb.com/ - Cheap PCB!
- https://www.ti.com/lit/ds/symlink/sn74hc595.pdf
- https://www.ti.com/lit/ds/symlink/uln2803a.pdf?
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