I have read about distance limitations of timing critical signals like communication over SPI. In order to get more distance between my Pi and my sensor I am considering using an analog sensor and an ADC.
Question: What should I know when considering the distance between my analog output and my ADC input? I am, at the moment, considering the impact on:
- Linearity of sensor output and ADC readings
- Delay between sensor output and ADC reading
- Sensor output voltage: 0.25 to 4.75 V
- ADC input voltage: 0 to 5 V
- I hope to sample the sensor output at 50 kHz (seems a bit fast and too fast for SPI over a 1m distance)
- I'm not really sure how to calculate the amperage the ADC will draw from the sensor output.
Insight and references are welcome!
I think a minimum of 8 significant bits is what I can work with. With a 500 unit range that's a measurement of 1/(2^8*500) = ±2 units.