One other thing. In order to get accurate readings, as the Motronic sees them, you will need to use the 5V reference voltage that comes from the Motronic. The 5V wire that powers the AFM is also the internal reference voltage for the Motronic's ADC, so you will need to use that 5V line as the reference for your ADC and the DAC.
For the voltage regulator, see about using an adjustable one and set it to 5.2V or so (obviously you will need 12V input). Opamps generally cannot output all the way up to the power supply voltage, so using 5.2V gives you a little headroom. Most microcontrollers also do not like having any voltage on a signal pin (0-5V) that is higher than the supply voltage (4.75-5.25V from a typical 7805) and I think that any "5V" microcontroller should be perfectly fine with 5.2V power input. For linear vregs, I like to use the LT3080 since it only needs one resistor to set the output voltage, although it is a hell of a lot more expensive than a 7805. Still, $4 is not too bad in the grand scheme of things.
When you get to the point of thinking about ordering the electronic bits and have a schematic sketched out, feel free to post it up and I can give you some pointers. Bypass/decoupling caps are vital when you want to measure analog signals accurately, as well as signal filtering.
For the voltage regulator, see about using an adjustable one and set it to 5.2V or so (obviously you will need 12V input). Opamps generally cannot output all the way up to the power supply voltage, so using 5.2V gives you a little headroom. Most microcontrollers also do not like having any voltage on a signal pin (0-5V) that is higher than the supply voltage (4.75-5.25V from a typical 7805) and I think that any "5V" microcontroller should be perfectly fine with 5.2V power input. For linear vregs, I like to use the LT3080 since it only needs one resistor to set the output voltage, although it is a hell of a lot more expensive than a 7805. Still, $4 is not too bad in the grand scheme of things.
When you get to the point of thinking about ordering the electronic bits and have a schematic sketched out, feel free to post it up and I can give you some pointers. Bypass/decoupling caps are vital when you want to measure analog signals accurately, as well as signal filtering.
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