IR to Network Bridge with an ESP8266

A year or so ago we cut the cord (cable) and started relying on a combination of OTA tuning via a Windows media center, the OTA tuner in our TV and a Roku stick. The original thought was the limited programming selection would push us to spend less time watching TV to focus on more productive things. (Spoiler - It never happened, somehow network programming filled the void.)

This setup has a pretty high WAF (wife approval factor) mainly since the media center handles IR and is controlled along with the TV via a single Harmony universal remote - but that damn Roku remote presents a number of issues:

1. It doesn't use IR (some sort of proprietary RF) and therefore can't be setup in the Harmony or other IR based universal remote.
2. It's also particularly small so seems inexplicably drawn into every nook and cranny in the furniture (or hidden by the kids)

One idea that was quickly dismissed (<WAF)

Attaching the small remote to the Harmony seemed a poor choice but something had to be done, the constant volume change within Roku apps had to be addressed!

One day I saw mention of a network API for the Roku and an idea was born... what if I setup a fake device in the Harmony and then used an ESP8266 to pickup the device IR and convert this to a corresponding network based Roku API call? The ESP was certainly capable of decoding IR (using one of the common Arduino libraries) and with it's on board WiFi it should be able to  make the REST API calls to the Roku.

A few hours later the IRtoRokuBridge was born. In a surprising twist this ends up even more capable than the original remote since you can program arbitrary shortcut buttons on the Harmony screen that take you directly into the requested app.

The code is pretty basic but it has been running well for 6 months or so. 

Two libraries/authors I leveraged and want to thank:

IRremoteESP8266: https://github.com/markszabo/IRremoteESP8266/
Telnet Debug https://github.com/JoaoLopesF/ESP8266-RemoteDebug-Telnet

You can find the code/details on my Github page (https://github.com/lawrence-jeff/IRtoRokuBridge) a few things I learned:

• Cheap off brand IR modules can give you issues with range and decode - switching my setup to use a name brand module (whatever Radio Shack sold 10 years ago) worked much better.
• The Arduino code isn't as resilient as what you will find on a TV or other device, you really need to aim.. I kept meaning to implement a less exact match in the code but it works well enough that I never got around to it
• If you use NEC codes holding down a button generates a unique repeat code which you need to handle. I found the Harmony sometimes sent these when not intended so via trial and error I filter out the first two repeat codes which makes it act better (this is for instances when you are holding down an arrow for instance to browse through the app menu)

This example uses the Roku API - but anything you can do on your home network you can now do via IR and a spare remote. Drop a comment if you do any other interesting things with IR control

ESP8266 and OpenHAB

ESP8266, MQTT and OpenHAB

Here is a quick little demo on how to use the ESP8266 as an ultra cheap ($3) sensor/control node for OpenHAB.

Setup

ESP8266 (ESP-01) with nodemcu LUA firmware (1/24/2015 build or later)
Mosquitto (or equivalent) mqtt broker running on your network (stock config)
OpenHAB installed and running the demo site (add all MQTT modules)

Circuit

This represents an independently controlled device that you also want to also be able to view/control in OpenHAB. The ESP-01 only has 2 available GPIO pins so this setup connects a button to GPIO0 (must be high on boot) and a LED on GPIO2. Standard power, enable and serial connections not displayed.

Basic circuit - Switch on GPIO0, LED on GPIO2

Procedure

Load the following code on the ESP8266

(See updated post for latest code)

This code is pretty basic and is hard coded to control one of the OpenHAB demo items (FF bathroom ceiling light). Before uploading replace the two instances of the mqtt broker IP with your value. This assumes you have a working LUA instance (1/24/2015 build or greater) and it is already configured to connect to your wireless network.

I used ESPlorer to load the files 

mqtt.lua

gpio.mode(3,gpio.INPUT,gpio.PULLUP)
gpio.mode(4,gpio.OUTPUT)
gpio.write(4,gpio.LOW)

m = mqtt.Client("ESP8266", 180, "user", "password")
m:lwt("/lwt", "ESP8266", 0, 0)

m:on("offline", function(con) 
     print ("reconnecting...") 
     print(node.heap())
     tmr.alarm(1, 10000, 0, function()
          m:connect("192.168.0.32", 1883, 0)
     end)
end)

gpio.trig(3, "down",function (level)
      local PinValue=gpio.read(4)
      --Change the state
      if (PinValue==1) then
         --The read resets the output to 0, put it back
          gpio.write(4,0)
          print("Light was on, turn off")    
          m:publish("/openHAB/in/Light_FF_Bath_Ceiling/state","OFF",0,0)
      else
          gpio.write(4,1)
          print("Light was off, turn on")    
          m:publish("/openHAB/in/Light_FF_Bath_Ceiling/state","ON",0,0)
       end
end)

-- on publish message receive event
m:on("message", function(conn, topic, data) 
     print("Recieved:" .. topic .. ":" .. data) 
if (data=="ON") then
          print("Enabling LED") 
          gpio.write(4,gpio.HIGH)
          m:publish("/openHAB/in/Light_FF_Bath_Ceiling/state","ON",0,0)
     elseif (data=="OFF") then
          print("Disabling LED") 
          gpio.write(4,gpio.LOW)
          m:publish("/openHAB/in/Light_FF_Bath_Ceiling/state","OFF",0,0)
     else
          print("Invalid - Ignoring") 
     end 
end)

tmr.alarm(0, 1000, 1, function()
 if wifi.sta.status() == 5 then
     tmr.stop(0)
     m:connect("192.168.0.32", 1883, 0, function(conn) 
          print("connected")
          m:subscribe("home/openHAB/out/Light_FF_Bath_Ceiling/command",0, function(conn) 
               m:publish("Debug","Starting",0,0, function(conn) print("sent") end)
          end)
     end)
 end
end)

init.lua

dofile('mqtt.lua')

Test the circuit and mqtt

If you just uploaded the code you need to restart the device and ensure it reports Connected and Sent to the serial out. (LUA is finicky and you may need to reboot a couple times).
At this point it would be good to verify the circuit and MQTT components work. The switch should turn the light on and off and you should see your broker receive messages for each change. (If using Mosquitto run it in verbose mode to see the messages coming in/out. (use -v)).

Configure OpenHAB demo to connect to MQTT and process the ESP messages

Add these lines to the mqtt config section in  
C:\openhab\configurations\openhab.cfg (if under windows)
Replace the IP and port with your MQTT broker details

mqtt:broker.url=tcp://192.168.0.32:1883
mqtt:broker.clientId=openhab
mqtt-eventbus:broker=broker
mqtt-eventbus:commandPublishTopic=home/openHAB/out/${item}/command
mqtt-eventbus:statePublishTopic=home/openHAB/state/${item}/state
mqtt-eventbus:stateSubscribeTopic=/openHAB/in/${item}/state

The lines above create an eventbus which allows you to control all OpenHAB items via mqtt. You can also skip the bus and individually connect a single item to mqtt but this is an easier way to start.

Test it all

Open the demo OpenHAB site (replace localhost with your OpenHAB values)

http://localhost:8080/openhab.app?sitemap=demo

Expand FirstFloor ->Bathroom
If you toggle the Ceiling light it should toggle the state of your led, if you press the button it should control the led and update the page.

Next Steps

OpenHAB seems to assume things work, for instance when you change the light state it actually changes the website state before it receives confirmation from the ESP, this seems less than reliable. I wonder if its possible for it to be in a pending state until the ESP process the change and sends back updated state details. (See Part 2 for details on how this can be fixed)