zondag 12 februari 2017

Program the Racal Cougar - Part 6

Arduino boxed up and connected to the E.C.U.

This post is about the hardware and software i used doing my experiments.

I used an Arduino Nano V3 (cheap clone) with a minimum of additional components, mostly to perform the level shifting and have a visual indication of the programming result.

At this moment there is no support for the Fill Gun functionality yet. This will be added in future version.


The Arduino is powered using the USB Host using an USB cable and requires no external power source.

The schema is simple, the most important parts are the Arduino itself and the level shifter made using the 2N7000 mosfet. A bicolor led is added to have some visual confirmation of the programming result and a reset button for reseting the Arduino program.

Installing the Arduino Sketch

After you have downloaded and installed the Arduino IDE (Arduino Getting started) it is best to test your Arduino by connecting it using an USB cable and load the "Blink" example available in your Arduino IDE.

If you have the "Blink" sketch running and the led at pin #13 is blinking you have successfully installed the IDE and managed to load a sketch to your Nano.

Next is the Racal Cougar Program sketch which can be downloaded using this link.

After you have downloaded, unzipped and opened the sketch (file ending with the .ino extension) in your Arduino IDE you can upload it to your Arduino. After successfully uploading the sketch it will start running and the red led and green led should light up for 1 second in turn indicating it is ready to go.

Next is opening the Arduino Monitor (console) which you can use to control the programmer. This can be done by pressing Ctrl + Shift + M. Make sure the line ending and baud rate of the monitor are set to "Both NL & CR" and 19200.

After opening the monitor console the following should be visible:

Main menu

More information about the programmer menu and functions is described in a previous post.

Supported PRM models

At this moment the software is configured and tested for use of the PRM4515L (4 meter) model only.   Although programming the other PRM4515 models is based on the same principal i haven't implemented this yet, mainly because currently i have no other models available to test the functionality with.

If you have one of the other models and want to test the programmer for a particilar model please let me know and i will make some changes to the software for you to test.

Update 05-03-2017:

Version 0.0.3 of the Arduino Racal Cougar Programmer now supports the PRM 4515 H models, see next post.

Update 15-10-2015:

 A new version v0.0.4 is available that fixes the default channel data being garbage when a fresh Arduino was used and channel data hasn't been stored before.


This is an experimental project and you are using this software at your own risk. I am not responsible for any damage to your precious Racal Cougar !

4 opmerkingen:

  1. Hi Dave thank you for an interesting read and its given me an idea of making a programmer myself ,
    But ive come acròss a problem trying to upload the sketch to the nano,
    Wonder if you could help ?

  2. Hi, sorry for the late response... Sure i can help. What is going wrong uploading ? Are you able to load the "Blink" program into your Nano ? Drop me an email message with the output of your Arduino IDE showing the error message.

  3. Dave
    Great work you have done on this project. It was no trivial feet doing all the reverse engineering and of tremendous value to anyone who owns one of these radios (hopefully me, soon). Congratulations and thanks for sharing with us.