arduino as electronic speed controller/mixer

I am new to electronics and as a fun project I thought I would try to interface the arduino with a wireless reciever and an RC transmitter and basically program my own esc (electronic speed control) and mixer.

It seems that the arduino's analog reader will output a value between 0-1024 which maps between a voltage between 0-5volts. I was reading the voltage that comes from the reciever and it only seems to output a voltage between .374v to .220v so it basically always reads 0 from the analog reader. So I was wondering if there is anyway to modify the levels of the arduino to reader a much lower and finer voltage or if there is an easy way to multiply the voltage coming from the reciever?

Any help would be much appreciated.




The most common way to solve this is to use an op-amp to scale up the voltage swing of whatever sensor it is you're using, so that it maxes out at 5V. The op-amp is an all-round amplifier/converter chip for this kind of thing. See this page, which specificially talks about scaling sensors that put out less than 5V.

The other option is to use the AREF pin to tell the ADC what the maximum reference voltage is. There's not much documentation on this, but see Massimo's post half way down this page. He makes the very good point that at .5V full range, your resolution will be .5 millivolts, and noise will be a big issue! You would also need a very very very clean and stable .5V reference supply... many headaches indeed.

Hope this helps