I am thinking of using arduino as a datalogger for strain gauges measurements. The strain gauges already have amplifiers circuits, so I only need to read the voltage differences for each strain gauge.
The problem I have is that I need to log a lot of data; about 15 strain gauges and at about 100Hz?. So I need in any case a lot of analog inputs. Idealy I would also save all the data to an SD card. After reading on the forum, I saw some problems with Arduino uno and mega with saving data to SD card in a fast manner and being limited in the amount of data it can handle.
I start to tend towards the Arduino due, but I am not sure yet. Before buying anything, I would like to ask the community to help me and maybe get feedback from somebody that already did this?
Don't use the Due's analog side, its a poor performer.
I see you want 1500 samples a second, no sweat for an Uno or Mega (latter has 16 channels
and samples within 0.1ms). That's generating 3kB/s, so you need to check what
throughput is achievable to SDcard (you'd need to double buffer somehow for
smooth recording). Ensure the Arduino is powered from a noise-free 5V,
ie using the on-board linear regulator, not USB, otherwise you're analog
readings will be noisier. Use a separate 3.3V regulator to power the SD card, and
do not source this from the 5V rail (SDcard current consumption is spiky)
You can also look at external memory chips for storage too.
You may need some external analog multiplexing if all the inputs are differential.
So the question is can you get 3kbytes/s onto an SD card reliably? I don't know.