fix-cec

Get a Denon AVR to automatically power on/off an Optima projector.

Introduction

I found that when I powered on my Denon AVR (X4500) the Optima (HD142X) projector that it was connected to would not automatically switch on. This should work. But the HDMI protocol involved (called "CEC") is often not reliable, especially when combining products from different brands (Denon and Optima in this case).

Overview of solution

I connected a Raspberry Pi to one of the Denon AVR's HDMI inputs. I configured networking on the Denon AVR and the Raspberry Pi so that the Raspberry Pi could connect to the Denon AVR's IP address.

Running the code (main.cc) on the Raspberry Pi means that the Pi will notice when the Denon AVR is switched on and it will then switch on the Optima projector (via its HDMI cable). Similarly, when the Denon AVR is switched off, the Pi will notice and switch off the Optima projector.

Setting up the Denon AVR

You will need to configure some settings on the Denon AVR.

Set up networking

Make sure the Denon is connected to your network. I did this by going ito the Setup Menu->Network->Connection and configuring the WiFi connection. I gave the unit a static IP address (192.168.1.45) so that the Pi would have a predictable IP address to connect to.

I also set Setup Menu->Network->Network Control to be "Always On". This means that the Pi can connect to the AVR even when it is switched off.

Set up CEC

In Video/HDMI Setup I have set:

• HDMI Control = On
• Power Off Control = All
• RC Source Select = Power On + Source

Setting up the Raspberry Pi

I used a Raspberry Pi Zero W. I connected it to one of the space HDMI inputs on the back of the AVR. I installed Raspbian 10 on it. I configured networking so that it was able to connect to the Denon AVR's IP.

Install software on Pi

You need to have a C++ Complier installed

sudo apt install g++

Also, the make utility

sudo apt install make

install git

sudo apt install git

and also some libraries related to HDMI/CEC

sudo apt install libraspberrypi-dev libraspberrypi0
sudo apt install cec-utils libcec4

Configure /boot/config.txt

Add the following setting to the file /boot/config.txt

hdmi_ignore_cec_init=1

and reboot.

Download fix-cec

git clone https://github.com/stuart-mclaren/fix-cec

Building fix-cec

Edit main.cc to set the IP address

First, before compiling you will need to edit the file main.cc to enter the IP address of your Denon AVR.

Change this line:

#define IPADDR "192.168.1.45"

to match your Denon AVR's IP address. Eg if the IP address is 192.168.0.100 change the line to:

#define IPADDR "192.168.0.100"

Compiling fix-cec

To compile the code, run the following (from inside the fix-cec directory):

make

This will create the file fix-cec.

Installing fix-cec

sudo make install

This will copy the binary to /usr/local/bin/fix-cec and configure a systemd service called fix-cec to run the binary automatically when the Pi boots.

You can check the service is correctly starting on boot by rebooting the Pi

sudo reboot

and then, once the Pi has booted, running:

systemctl status fix-cec

If it's working, the output should show:

● fix-cec.service - fix-cec service
   Loaded: loaded (/etc/systemd/system/fix-cec.service; enabled; vendor preset: enabled)
   Active: active (running) since Sun 2022-01-16 15:57:53 GMT; 6min ago
 Main PID: 394 (fix-cec)
    Tasks: 5 (limit: 421)
   CGroup: /system.slice/fix-cec.service
           └─394 /usr/local/bin/fix-cec
Jan 16 16:03:03 piston fix-cec[394]: Connected
Jan 16 16:03:03 piston fix-cec[394]: DPX: SKIP
Jan 16 16:03:03 piston fix-cec[394]: DPSI: SI=5
Jan 16 16:03:03 piston fix-cec[394]: DP: PSTRE 50
Jan 16 16:03:03 piston fix-cec[394]: DPX: SKIP
Jan 16 16:03:03 piston fix-cec[394]: DPSI: SI=5
Jan 16 16:03:03 piston fix-cec[394]: DP: PSTONE CTRL OFF
Jan 16 16:03:03 piston fix-cec[394]: DPX: SKIP
Jan 16 16:03:03 piston fix-cec[394]: DPSI: SI=5
Jan 16 16:03:03 piston fix-cec[394]: DP: SSSMG MOV
Jan 16 16:03:03 piston fix-cec[394]: DPX: SKIP

Note the "Connected" message: this means the Pi connected to the AVR's IP address successfully. The various DP messages are output from the AVR. The DPX messages are debug.

A note on logging

The code logs a lot. You will need to make sure that logs, eg in /var/log are rotated to avoid filling up the filesystem.

Alternatively, remove the various printf statements from main.cc.

Can I avoid the projector turning on in some cases?

In some cases, eg when using a turntable or the tuner, you may not want the projector to switch on when you turn on the AVR.

See the following note in the code for how to change this behaviour:

Note: For non-video sources

Basically add 100 to the source that you don't want to power on the projector for. Eg to prevent the projector turning on when playing vinyl records change this line:

phono = 9,

to this

phono = 109,

This assumes that you have the following set on the AVR

RC Source Select = Power On + Source

and you power on the AVR by pressing the Phono button on the AVR's remote control.

Acknowledgments

The code is based on https://github.com/glywood/cec-fix