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@@ -73,7 +73,35 @@ Pins |
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The [pinout guide for the Node151](http://resource.heltec.cn/download/LoRa_Node_151/LoRa_Node_151_Pinout_Diagram.pdf). |
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The pins PB5-7,9 are used as active low controls for the relays. |
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The default pins PB5-7,9 are used as active low controls for the relays. |
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They are mapped to channels 0 through 3 respectively. The LED on PB8 |
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is mapped to channel 4. This is useful for testing if a command works |
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or not. |
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The pin PB15 is used as an analog input for an RNG source. This pin |
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should be grounded. |
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Deploying |
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--------- |
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The noral supply used for irrigation values is 24V AC. This means |
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an additional power supply is needed to convert to the 5V supply that |
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is used by the Node151. Make sure this is well filtered as both the |
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relays on the board (talked about below), and the irrigation values |
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will cause significant noise. The first PS I made was a simple DC-DC |
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buck converter + a full wave rectifier which, while alone was enough |
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to power the uC, was not enough when the relays were actuated, and even |
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when a little bit of filtering was added after the rectifier (22uF), |
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enough to keep it happy w/ the relays, it was not enough when the |
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irrigation valves actuated. |
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In order to control the values, a relay board, similar to [this |
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one](https://www.amazon.com/ELEGOO-Channel-Optocoupler-Arduino-Raspberry/dp/B01HEQF5HU), |
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can be used. The nice thing about this board is that the GPIO pins |
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on the Node151 are 3.3V, while the relays need 5V to work. The jumper |
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on the right side, VCC-JD-VCC, can be removed to allow this. The GND |
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on the input/VCC pinout is used for the relay power via JD-VCC, and |
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NOT for the VCC->INx pins, despite them being next to each other. The |
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GND and JD-VCC should be connected to the 5V power supply, while VCC |
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is connected to VDD on the Node151, and INx pins to the respective |
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GPIO pins. |
