Hi,
As one of my 'isolation projects' I am trying to build an interface which reads the analogue inputs from my steering wheel controls in my car to my aftermarket head unit.
I have been following this thread Steering wheel remote audio control - General Electronics - Arduino Forum which takes a lot of learning from this as well - http://www.jvde.net/node/7.
I am this for my Australian '08 Ford BF Falcon. It has an Pioneer MVH-S305BT head unit in it.
Due to availability of parts I can't get a MCP4131 100k so instead have the MCP4151-104E/P which is also 100k and gives me 256 steps.
So far this has not been very successful but I have not given up! I have a few questions and I was hoping to get some guidance.
- To address all 256 steps do I use the same byte address, 0x00 or do I use 0x11?
- I have been converting the 128 step values to 256 step values simply by doubling them. For example, a 15k resistance on a 128 step has a value of 21 so I doubled that to 42. Is that correct?
I have also made some changes to the wiring as I am tapping into the SWC line in the car rather than disconnect it. As a result I do not need to power it and I left the 10k resistor in the circuit to read AnalogueIN on the Arduino.
I have also powered the LOW at 3.3v, not doing this meant that the Pioneer did not recognise there was a wired remote plugged into it at all.
So far I have it at least recognising that there is a wired remote plugged in and it is asking me to "Press VOL+ for 1 second" which should introduce ~15k resistance to the line. This has not produced any positive results. I have moved the wiper values around but I am not getting a response from the Pioneer unless I take the value to 128+ in which case it errors on me immediately with 'Try Again'.
It has been 20+ years since I did electronics like this so I am now really green. Any help is appreciated!
If you need anymore information or the code please let me know.
