Hello
Is it possible the empeg be configured to increase the volume on measured volts on the Dashboard Illumination input?

Cheers
Ed

Not by default, no. You would have to write your own modified kernel to do it. But it's theoretically possible.

The microphone input may be a better bet.

Hi
With advice from two giants on the forum I should explain where I came to ask from. My car has a GAL (speed) signal on the ISO loom but i can't write code. I have a cabriolet and have a spare 2.5mm mic from a damaged car kit. Thank you.

Speed-senstive and microphone-senstive volume control for the empeg have been discussed on this BBS before. So far, no one has implemented it. I'm in the same boat as you, wishing for the feature, but without the technical know-how to implement the feature myself.

If a chum can write the code can somebody supply the source and compile the kernel?

Generally, writing the code involves some trial-and-error, so whoever is doing the work needs the empeg and the cross-compiler, and ways to test it.

The headlight line cannot be used - it is a digital input. Ditto for the mute line. If you were electronically competant then you could build a circuit to encode the voltage as a PWM signal and then measure that on the empeg. You'd need to hack the kernel.

The microphone input is _probably_ ac-coupled. So you'd need to modulate the dc voltage onto an ac waveform in order to measure it. Again, you'd need to hack the kernel. You'd lose the use of visuals in Tuner and Aux In modes.

A third solution is to digitise the voltage, and encode it into a serial RS232 message. You could write a user-land application to listen to the messages and adjust the volume.

A fourth solution is to buy a low cost GPS receiver and hack the empeg GPS software to ask for the GPS calculated speed.

The sensor is rather crude, being a magnetic reed switch, the final drive crown wheel carrying vanes which periodically shield the magnet and so make the switch drop out.

The result is a negative-going square wave, the frequency of which increases with road speed. The pulse width will of course reduce with speed, but I would not call it pulse width modulation.

Sorry for bumping up an old thread

Quote:
The headlight line cannot be used - it is a digital input.

Won't this line trigger on the change from Logic High to low? What is themaximum scan frequency on it?