ADC out

[bluejets]

Need to input r/c receiver pulse 1 to 2 ms and use this to generate a proportional out voltage. I have thought about generating a mark/space signal as an output and then perhaps smooth it with a cap. Much like a flashing led. Question is........ other than the scan rate would there be other things to consider? If i keep the mark space at say for example 300/170ms rather than 30/17, I thought the scan rate would be less of an issue.

or should that be DAC out..

 

[hippy]

The technique you are thinking of is known as "RC" ( resistor-capacitor) and is usually driven by PWMOUT; change the duty and through the RC this changes the voltage. Mark-Space ratios of 300/17ms are quite slow so not that good but PWMOUT can give much higher frequencies.

Using DAC will give more stable voltages ( less ripple ) but you are limited to only 32 voltage levels, though you can vary DAC and use RC to create more, but again that introduces ripple and probably more so than using PWMOUT and an RC.