add pi gpio

lib/features/digitalRelay/implementations/piGpio/index.ts

@@ -0,0 +1,46 @@
+import { exec } from 'child_process';
+import { promisify } from 'util';
+
+const execAsync = promisify(exec);
+
+export class PiGpio implements DigitalRelay {
+    private pin: string
+
+    constructor(){
+        this.pin = process.env.GPIO_PIN || '26'
+    }
+
+    async setup(): Promise<void> {
+        try{
+            console.log(`Setting up GPIO pin ${this.pin}...`)
+            await execAsync(`echo ${this.pin} > /sys/class/gpio/export || true`);
+            await execAsync(`echo out > /sys/class/gpio/gpio${this.pin}/direction`);
+        } catch(e){
+            console.log(`Error during setup..`)
+            console.log(e)
+        }
+    }
+
+    // Power on the DUT
+    async on(): Promise<void> {
+        console.log(`Toggling gpio pin ${this.pin} on`)
+        await execAsync(`echo 1 > /sys/class/gpio/gpio${this.pin}/value`);
+    }
+
+    // Power off the DUT
+    async off(): Promise<void> {
+        console.log(`Toggling gpio pin ${this.pin} off`)
+        await execAsync(`echo 0 > /sys/class/gpio/gpio${this.pin}/value`);
+    }
+
+    async getState(): Promise<string> {
+        // TODO return state of power on/off
+        let res = await execAsync(`cat /sys/class/gpio/gpio${this.pin}/value`);
+        return res.stdout
+    }
+
+    async teardown(): Promise<void> {
+        await this.off();
+    }
+
+}

lib/features/digitalRelay/index.ts

@@ -1,8 +1,10 @@
 import { DigitalUSBRelay } from "./implementations/usb-relay";
 import { DummyDigitalRelay } from "./implementations/dummy-digital-relay";
+import { PiGpio } from "./implementations/piGpio"
 
 const digitalRelayImplementations: {[key: string]: Type<DigitalRelay> } = {
 	usbRelay: DigitalUSBRelay,
+	gpio: PiGpio,
 	dummyPower: DummyDigitalRelay,
 };