implimenting LED netreciever colour control file

cmd/rv/main.go

@@ -67,10 +67,12 @@ import (
 	"bitbucket.org/ausocean/av/container/mts/meta"
 	"bitbucket.org/ausocean/av/revid"
 	"bitbucket.org/ausocean/av/revid/config"
+	"bitbucket.org/ausocean/av/led"
 	"bitbucket.org/ausocean/iot/pi/netlogger"
 	"bitbucket.org/ausocean/iot/pi/netsender"
 	"bitbucket.org/ausocean/iot/pi/sds"
 	"bitbucket.org/ausocean/utils/logger"
+
 )
 
 // Copyright information prefixed to all metadata.
@@ -178,6 +180,10 @@ func main() {
 // run starts the main loop. This will run netsender on every pass of the loop
 // (sleeping inbetween), check vars, and if changed, update revid as appropriate.
 func run(rv *revid.Revid, ns *netsender.Sender, l *logger.Logger, nl *netlogger.Logger) {
+	led_, err := led.NewLED(*l)
+	if err != nil {
+		l.Log(logger.Error, pkg+"could not create LED", "error", err.Error())
+	}
 	var vs int
 	for {
 		l.Log(logger.Debug, "running netsender")
@@ -212,6 +218,10 @@ func run(rv *revid.Revid, ns *netsender.Sender, l *logger.Logger, nl *netlogger.
 		}
 		l.Log(logger.Debug, "got new vars", "vars", vars)
 
+		err = led_.Update(vars["ledcolours"])
+		if err != nil {
+			l.Log(logger.Error, pkg+"could not update led", "error", err.Error())
+		}
 		// Configure revid based on the vars.
 		l.Log(logger.Debug, "updating revid's configuration")
 		err = rv.Update(vars)

led/led.go

@@ -0,0 +1,156 @@
+/*
+DESCRIPTION
+  LED.go provides an implementation of the LED interface for a basic
+  multicolour LED using a background python process responsible for the
+  hardware interfacing.
+
+AUTHORS
+  Alex Mastersson <alexm@ausoean.org>
+  Saxon Nelson-Milton <saxon@ausocean.org>
+
+LICENSE
+  Copyright (C) 2020 the Australian Ocean Lab (AusOcean)
+
+  It is free software: you can redistribute it and/or modify them
+  under the terms of the GNU General Public License as published by the
+  Free Software Foundation, either version 3 of the License, or (at your
+  option) any later version.
+
+  It is distributed in the hope that it will be useful, but WITHOUT
+  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+  FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+  for more details.
+
+  You should have received a copy of the GNU General Public License
+  along with revid in gpl.txt. If not, see http://www.gnu.org/licenses.
+*/
+package led
+
+import (
+	"fmt"
+	"io"
+	"os/exec"
+	"time"
+
+	"bitbucket.org/ausocean/utils/logger"
+)
+
+// Background process constants.
+const processStartWait = 5 * time.Second
+
+// LED is an implementation of the LED interface for a standard Multicolour LED.
+type LED struct {
+	cmd    *exec.Cmd
+	stdin  io.Writer
+	stdout io.Reader
+	r,g,b  int
+	log    logger.Logger
+}
+
+const pin = 5
+
+// NewLED returns a new LED.
+func NewLED(l logger.Logger) (*LED, error) {
+	s := &LED{log: l}
+	s.cmd = exec.Command("python3", "-c", LEDScript)
+
+	var err error
+	s.stdin, err = s.cmd.StdinPipe()
+	if err != nil {
+		return nil, fmt.Errorf("could not pipe stdin of process: %w", err)
+	}
+
+	s.stdout, err = s.cmd.StdoutPipe()
+	if err != nil {
+		return nil, fmt.Errorf("could not pipe stdout of process: %w", err)
+	}
+
+	s.log.Debug("starting LEDCommand process")
+	err = s.cmd.Start()
+	if err != nil {
+		return nil, fmt.Errorf("could not start servCommand process: %w", err)
+	}
+	
+	time.Sleep(processStartWait)
+
+	return s, nil
+}
+
+func (s *LED) Update(v string) error {
+	_, err := s.stdin.Write([]byte(v + "\r\n"))
+	if err != nil {
+		return fmt.Errorf("could not write rgb to LEDCommand process: %w", err)
+	}
+	return nil
+}
+
+
+// Shutdown kills the LED command background process.
+func (s *LED) Shutdown() error {
+	s.log.Debug("shutting down")
+	err := s.cmd.Process.Kill()
+	if err != nil {
+		return fmt.Errorf("could not kill LEDCommand process: %w", err)
+	}
+	return nil
+}
+
+
+func main(){
+	var l logger.Logger
+	_, err := NewLED(l)
+	fmt.Println(err)
+}
+
+
+const LEDScript = `
+import sys
+import time
+import RPi.GPIO as GPIO
+GPIO.setmode(GPIO.BCM)
+GPIO.setwarnings(False)
+
+GPIO.setup(17, GPIO.OUT)
+GPIO.setup(18, GPIO.OUT)
+GPIO.setup(27, GPIO.OUT)
+
+red = GPIO.PWM(17,120)
+green = GPIO.PWM(18,120)
+blue = GPIO.PWM(27,120)
+
+redbr=50
+greenbr=50
+bluebr=50
+
+red.start(0)
+green.start(0)
+blue.start(0)
+
+def main():
+    rgb = [0,0,0]
+
+    while True: # one loop per line
+      
+        rgb[2] = 0
+        next = sys.stdin.readline()
+        if next == "":
+            time.sleep(3)
+        else:
+            string = next.split(",")
+            rgb[0] = int(string[0])
+            rgb[1] = int(string[1])
+            rgb[2] = int(string[2].strip("\n"))
+            
+            print(rgb)
+            rgblight(rgb[0],rgb[1],rgb[2])
+            time.sleep(3)
+    print("loop break")
+    
+def rgblight(rpwm,gpwm,bpwm):
+    red.ChangeDutyCycle(rpwm)
+    green.ChangeDutyCycle(gpwm)
+    blue.ChangeDutyCycle(bpwm)
+
+main()
+
+`