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hi there,
i need a 12-bit resolution for some of my analog measurements in a project, so i change the resolution in setup() like so:
analogReadResolution(12);
other parts of the code need only a 10 bit resolution.
since this project should run at low latency... is there any speed difference in reading 12 bits and bitshift by 2 (>>2) v.s. setting the resolution to 10bit?
Yes, but I encourage your to measure how much yourself.
Hallo lokki :)
I tested the ADC in the Teensy 4.1. The ADC is very noisy. A resolution of 12 bits is hardly usable. The ADC reference voltage is coupled to VCC. That is a big problem. External smoothing of the ADC reference voltage is not possible. I shifted the resolution to 7Bit and set analogReadAveraging to 32. I use potentiometers at the ADC input for parameter setting from 0-127 of the envelopes.
My measurements
12Bit resolution with noise (Averaging to 32 and read interval every 50ms)
https://i.ibb.co/2NZDNRK/12-Bit-noise.jpg
10Bit resolution without noise (Averaging to 32 and read interval every 50ms)
https://i.ibb.co/GnMdTsC/10-Bit-noise.jpg
8Bit resolution without noise (Averaging to 32 and read interval every 50ms)
https://i.ibb.co/ng6NPqB/8-Bit-noise.jpg
12Bit resolution shift 4 to right without noise (Averaging to 32 and read interval every 50ms)
https://i.ibb.co/FxZyc0v/12-Bit-shift-Right4-noise.jpg
Code:init analog Inputs
analogReadResolution(12);
analogReadAveraging(32);
..
I think an external 12Bit ADC chip is the better solution, e.g. MCP 3208-CI / P.
Best regards from Germany. Rolf
Unfortunately, I cannot edit my post. The image title is incorrect. It is called with noise not without. Sorry ..