CXA81-IR-Remote-Server

About The Project

I initially wanted to control my Cambridge Audio CXA81 amplifier from anywhere in the range of my home Wifi instead of the IR remote control. I figured this would be a great project to start open sourced from the beginning. I’m sure if you have come to this page you are looking for something for your CXA81 too. It’s unfortunate that Cambridge Audio doesn’t connect their StreamMagic app to their CXA series. Currently if you wanted to control your CXA81 you have to have a compatible CXN streamer. I don’t have one. You probably don’t either. ?

There are a couple ways that you can connect to the CXA81 besides IR. I’ve found that IR is the quickest/easiest and most robust connection which includes volume control whereas
the other methods such as RS232, and the Control Bus (Orange RCA plug on back panel)

I took some inspiration from Turning a Cambridge Audio Amp On With A Phone but
ultimately had to brute force the codes with the IR Transmitter, a bash script that looped through Claas Langbehn’s RC-5 Template, a gigantic lirc config file, and some go old fashioned time.

Built With

The links here are just suggestions for the items used in this project. They do not contain any tracking or affiliate links as far as I know. I also don’t claim that these are the least expensive products you could pick up either.

Hardware:

Software:

Getting Started

As you can see from above this project has been built on a Raspberry Pi Zero W with some IR Transmitters/Receivers. There is a chance that this will work on other Rasperry Pi boards as well. I’ve tried to keep it as generic as possible but cannot vouch for any other boards/configurations at this point. I plan on testing on a couple boards in the future but for now I can vouce for the Raspberry Pi Zero W.

You will need to download and flash the Raspberry Pi OS Lite to a Micro-SD card. I used a 16GB Micro-SD card just fine here. You won’t need a huge one for this to work.
After you have downloaded the OS here: Raspberry Pi OS Lite, you need to flash the image to the Micro-SD card.
To do this you can use BalenaEtcher which I highly recommend as it does the job well, has some safeguards built in so you don’t delete the wrong drive and is cross platform.

When you have the image flashed, created a file called ssh to remote into it Tutorial Here have set your wifi in the wpa_supplicant.conf file Forum Post Here. Boot the Raspberry Pi Zero W for the first time and you should be able to remote into it using ‘SSH [email protected](your pi IP Address)’ on a Linux machine with the default password ‘raspberry’.

To find out the IP Address of your pi you can either visit the web interface of your router and cross your fingers that they have the feature to see all of the machines connected or you could use nmap. The scope of installing NMap is outside of this project but you can follow a tutorial Here for Debian Based Linux Operating Systems such as Ubuntu. On Windows/Linux/MacOS you can use the ‘arp -a’ command in the terminal to retrieve machine names and IP addresses. This isn’t always a reliable way of pulling this info, but for this purpose it should work.

Prerequisites

  • Install Git on the Raspberry Pi Zero W.

sudo apt update
sudo apt install git

Verify the Git installation.

git --version
  • Install Golang on RPi Zero
    Tutorial

  • Install LIRC on Rasberry OS Lite

sudo apt update
sudo apt install lirc
  • Edit the /boot/config.txt file.
sudo nano /boot/config.txt

Where it says ‘#dtoverlay=gpio-ir-tx,gpio_pin=18’ change the line to ‘dtoverlay=gpio-ir-tx,gpio_pin=13’. I use GPIO 13 in my setup and for the sake of simplicity you should use the same pin for now. This pin is GPIO 13 PWM (physical pin 33). You can find a reference image of the pinout diagram at the bottom of this README.

Place the ‘cambridge.lircd.conf’ file located in the LIRC-Remote folder of this repository into the ‘/etc/lirc/lircd.conf.d/’ folder.

sudo cp cambridge.lircd.conf /etc/lirc/lircd.conf.d/

IMPORTANT SIDENOTE:
To make changes to the configuration in the future you will need to stop the lircd service, make your changes, then start the service again.

Stop lircd daemon:

sudo service lircd stop

Start lircd daemon:

sudo service lircd start

Now you must reboot your RPi Zero W.

sudo reboot

Installation

For now I will share with you how to clone and compile the go code in this repo. In the future I might just add some binary releases.

Install Go on Rasperry pi. You can follow this tutorial to do get Go installed on the RPi Zero W

References

Image Source: (https://freesvg.org/raspberry-pi-gpio-diagram) Creative Commons License. (https://creativecommons.org/publicdomain/zero/1.0/) The author of this image does not in any way shape or form endorse this project.

GitHub

View Github