The thread on an open source DMM as well as my own desire to have certain types of instruments that should cost much less than they do, has gotten me thinking of embarking on an ambitious project: creating an open-source data acquisition framework along with some reference starting hardware.
I'm curious if anybody would want to
- dissuade me
- get involved
- provide advice
Here's my vision:
- establish a simple mainframe connector and protocol that would provide
- data xfer (maybe USB3?)
- triggering and other synchronization (both directions)
- a few useful clocks (10 MHz, etc)
- device ID
- bipolar analog supplies (maybe +/- 30V, +/- 15V, +5V)
- on top of that, a software library that
- can manage the hardware protocol above
- can enumerate devices,
- provides data structures for aggregating and aligning data from multiple "cards"
- provides primitives for trigger, drain, real-time capture, etc.
From the physical hardware perspective, we'd start out with two devices:
A) a mainframe "motherboard" sporting a reasonable processor capable of running Linux or whatever, and providing several copies of the hardware interface specified above, maybe four. Also would have the basic IO we expect from computers: ethernet, maybe video, USB, etc
B) an "example" DAQ module that would speak the protocol above and maybe provide voltage measurement in a few ranges
To make it all feasible, design for a total bandwidth per card of, say 250 ksps (16b samples) and a total bandwidth for the motherboard of 1 Msps if capturing from all four simultaneously.
If this turned out interesting, people might be inspired to build other DAQ boards that fit the protocol.
From this infrastructure, we could move into a world where people can build whatever they want, for maybe not too much money: power analyzers, LAs, protocol analyzers, etc. Basically, an open source NI-like ecosystem.
Everything would be OSH/W.
-- dave j