Pages: [1]   Go Down
Author Topic: Analog-to-digital conversion on Arduino Uno R3 and Arduino Mega 2560?  (Read 671 times)
0 Members and 1 Guest are viewing this topic.
Offline Offline
Newbie
*
Karma: 0
Posts: 3
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

I've heard rumors that Mega has a higher precision, though I do not understand how this can be true if the scale of analogRead is still from 0 to 1024.

How can I argue for use of digital data-over-I2C (13-16 bit data) versus analog accelerometers from the ADC standpoint?
Logged

France S-O
Offline Offline
Edison Member
*
Karma: 41
Posts: 2174
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

No it's false.
As for every AVR you can enhance the AtMega328p ADC resolution. See Atmel Application Note : AVR121.

Uno board is for initiation only, she does it well, it was not expected for professionnal use.
I don't know the Mega layout but Uno layout is very poor concerning analogical signals.
No analogical ground near A0-A5 pins, the layout of Aref line is an horror : I have to sold 100nF capacitor directly on the micro socket to have stable measurment, and so on ............
Logged

Montreal
Offline Offline
Faraday Member
**
Karma: 27
Posts: 2565
Per aspera ad astra.
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

Quote
How can I argue for use of digital data-over-I2C (13-16 bit data) versus analog accelerometers from the ADC standpoint?
I'd vote on digital-over-I2C, just note arduino has slow I2C < 400kHz
Logged

Global Moderator
Boston area, metrowest
Offline Offline
Brattain Member
*****
Karma: 518
Posts: 26378
Author of "Arduino for Teens". Available for Design & Build services. Now with Unlimited Eagle board sizes!
View Profile
WWW
 Bigger Bigger  Smaller Smaller  Reset Reset

I'd go with digital over SPI, much faster.
Here's a simple chip to start with - 8 channels of 12 bit ADC
http://www.microchip.com/wwwproducts/Devices.aspx?dDocName=en010534
http://www.digikey.com/product-detail/en/MCP3208-CI%2FP/MCP3208-CI%2FP-ND/305928
Logged

Designing & building electrical circuits for over 25 years. Check out the ATMega1284P based Bobuino and other '328P & '1284P creations & offerings at  www.crossroadsfencing.com/BobuinoRev17.
Arduino for Teens available at Amazon.com.

Pages: [1]   Go Up
Jump to: