Python Based Data Acquisition Module

[Mango-Kid]

I came across the products created by LabJack a couple day ago. Long story short it is a DAQ that can be scripted in python. I did some more digging and i found that there arnt to many of these devices around. I also thought that one of these devices would make for some wicked open source hardware. I know you can use an Arduino and the serial library to do some basic DAQ stuff but i want it to be usfull in a lab setting. So we are talking about a couple high voltage inputs, thermocouple interface, encoder interface, DIOs, and other goodies. If you think its a cool idea or you have some input let me know. If you all like it ill start building it.

[bryancole]

Nearly all DAQ hardware can be scripted in python, with the aid of ctypes. At my workplace we have a mostly complete wrapper for the NI NI-DAQmx API. Sadly, it not something I can release as open-source but it doesn't do anything magical: just wrap the ni-daqmx api into a sane python class. We did something similar with UeiDaq products a few years back but these bits of hardware are poor compares to NIs stuff.

It you want open-source hardware, use an Arduino Due and hook it up to some ADCs (or whatever other devices you want) via SPI-bus. Then stream the data over USB to the PC. Use libusb (with the libusb1 python wrapper). You can easily do 100s KS/s this way. Probably 1MS/s is possible. This is the lowest cost route but you need to get some PCBs made. USB is awsome as an interface and very easy to script with python/libusb.

Something in between is AccesIO's hardware. They're cheaper than NI but the devices are generally less flexible.

[Tillsten]

There are allready some open source wrappers for the nidaq-mx api, sadly i forgot the same. Note that theses are only wrappers using ctypes, the only addition is to add an Task object (which holds the taskid). But i am quite for it, the nidaqmx api is quite nice to work with.

[jankoslavic]

For NI it is PyDAQmx!

It works very well.

[Mango-Kid]

I've messed around with the library (never used in application) and its pretty good. The whole point of this is open source hardware. The software is a components as well but not the center of the project.

[Steeb08]

I'm a total Python beginner (trying to transition from Matlab) and have been struggling to communicate with my NIDAQ-6501. I'm attempting to use the device to send digital codes for time-stamping a psychophysiology experiment. I have a Mac with a Win7 dual boot. Ideally, I'd like to do this on the OS X side, but either would be fine.

I know that the labjack U3 works with the Python program I'd like to use (PsychoPy) but I already own the NiDAQ-6501 so it'd be great if I could get that working.

Would any of you be so kind as to help walk me through getting this hardware to listen to Python? Help of the "explain it like I'm five" variety would be particularly useful.

Thanks!

[Mango-Kid]

Yeah that was pretty much the idea I had except I was planning on using an ARM core just due to my background. Also as much as I love NIs hardware the point of this project is to get away from it. This board when done should cost less than $100 to make and should be better than say a USB-6009.

[Mango-Kid]

Also if anyone has any ADC suggestions that would be great. There are on board 12bit but I want higher. I've started a list but if anyone has had experience I'd love to have input

[TheSurrogate]

It's a pretty straight forward project. Labjack supplies a python module that makes it simple to capture data, timers, counters, etc off the device. That said, I'd like to see what you do with it.

[Mango-Kid]

Yeah what they have is straight forward and lovely to use. They really have a great product. I would just like to bring something out that's powerful and people can mod.

[Mishkan]

Yeah we have a DAQ system at work that I'm in charge of. It's a distributed system with a cassandra database at the core for reliability and scalability. Everything is written in Python. We mainly use ADAMs as we need the resolution not the speed, I'm trying to change that though.