ADC Uno32 bit resolution, can it be changed?

Created Fri, 07 Mar 2014 07:27:28 +0000 by DennyP

DennyP

Fri, 07 Mar 2014 07:27:28 +0000

Hello guys,

I was wondering if the chipkit32 Uno supports resolution change from the default 10bits to say 12, just like the Arduino Due with the analogReadResolution(bits)?

Cheers, Dennis

majenko

Fri, 07 Mar 2014 15:39:43 +0000

Alas not. The ADC in the PIC32MX chips is a 10-bit ADC, so you can't magic more resolution out of it.

You'd have to use an external higher resolution ADC chip, such as the MCP3208 (12-bit, 8 channel, available on a handy breakout board here: [url]http://www.ebay.co.uk/itm/181322596646[/url]), or the MCP3553 (1 channel, 22 bit differential - board soon to be released for that one). Both those chips are SPI, but there are of course I²C options available from most ADC manufacturers.

EmbeddedMan

Fri, 07 Mar 2014 16:17:55 +0000

Dennis,

To a certain degree, you can create more bits of resolution on your own by oversampling. If you take 16 samples and average them together, you can sort of get an extra 4 bits. This won't be as good as a real ADC with a higher resolution, but you can also use that opportunity to do some digital FIR filtering to help you pick up your desired signal more strongly. Of course you trade off speed for this.

*Brian

pito

Wed, 12 Mar 2014 20:50:10 +0000

To a certain degree, you can create more bits of resolution on your own by oversampling. If you take 16 samples and average them together, you can sort of get an extra 4 bits.

..for each additional bit of resolution, the signal must be oversampled by a factor of four.. ..it means to get 4 additional bits you have to use 256x more samples..