I am trying to determine the best way to incorporate many sensors and serial connections in an arduino project, and if it is feasible to run so many things on 1 uC. The project is a pressure testing vessel that uses 24v hardware to feed pressure into a chamber as well as 24v sensors to read the pressure. I already know that the arduino’s 10 bit dac is too low of resolution for my application so i will be using an i2c 18 bit DAC to feed a 4-20ma interface which goes to the pneumatic controller. I will also need an 18 bit ADC to read the pressure from a transducer (1-5v analog)
For the interface, I really like the smartgpu2 as it seems to only take serial commands from the arduino and does all the graphics processing on its own. Basically the interface needs to graph/plot the pressure over time (smartgpu2 has a RTC) and log the data to a file, which the smartgpu2 does have the capability for. The smartgpu2 api uses points and lines and should be able to make a decent plot in realtime (< 10hz sampling) Does anyone have any experience using the smartgpu2? Is there anything else someone would recommend? The machine also must be able to serve the data over ethernet (maybe using webserver?) and if requested print the data on a serial thermal printer.
The biggest question is will an arduino uno (or mega) be able to handle all the serial connections simultaneously? Do serial connections interfere with timing or datalogging (or reading i2c DACs and ADCs?) Obviously alot depends on the programming but will I run into any physical limitations like memory (arduino mega) or processing power? I have seen each of these things work with arduino (ethernet, thermal printer, smartgpu2, DACs, ADCs) but does anything quirky happen when they are all used (at the same time)?
Here are links to the hardware I plan on using, I am open to any suggestions as well:
using something like this to interface, http://www.adafruit.com/products/1085
obviously some other circuitry necessary for the 4-20ma loop, http://arduinoforgoodnotevil.blogspot.com/2012/04/how-to-connect-4-20ma-sensor-to-arduino.html
From what I’ve read the shield with the wiznet 5100 chip is less demanding on the arduino than a enc28J60 type ethernet as the wiznet chip does all the tcp handling.
24v interfacing is going to be done with a dedicated circuit using optocouplers and solid state relays, there seems to be quite a bit of information on arduino interfacing with 24v industrial gear.
Thanks in advance for any help or guidance, I have some experience programming with arduino and have done some datalogging projects/PID stuff but never as many sensors at once.