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Jeffr wrote:It did not look encrypted. It also didn't look like canbus. I just took a cable and cut it in the middle so I could hook the probes in-line wherever I wanted.
I believe what you will need to do is make a high-pass filter/amplifier to extract and boost the incoming signal. Then you will need a reasonably high quality oscillator and something like a PLL to extract a binary signal. The signal comes quite rapidly so you will also want some kind of register to feed it in parallel to a microcontroller to keep the clock rate down.
On the output side you will need a big enough cap to hold the juice to raise the line level for the signal as well as the reverse of the above. A register for the micro to write to, the pll and other output drivers.
On top of this you will need some collision detection logic. If you are going to intercept and modify signals as I wanted to you'd need all of this 2x in order to modify the signals in-line.
That's where I stopped. It is feasible but the number of parts involved is too great for me to handle solder reasonably.
Jeffr wrote:The problem with a DSP or FPGA is of course power. That's why I mentioned registers on input/output to permit the micro to run at a low clock rate. Remember this system is always on. Always running. I suppose if it can wake up fast enough to still capture and demodulate the signal when it changes you could do something reasonable. I was doing that with interrupts on the avr.
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