Git repo for Linux SDK 1.1 from Dataq
The intent is to adapt this old Dataq Linux beta code from 2007, identified as version 1.0 on the web page but 1.1 in the archive file, written for the DI-154 and DI-194 (long obsolete) to the current model DI-1120 which replaces the DI-155, and the DI-4208. Since the DI-1120 replaces the DI-155, and it is only one count away from the DI-154, adapting this old code might be straightforward.
The Dataq line of starter kits offers amazing analog front end value. In particular, the DI-1120 and DI-4208 were chosen for their specific features and price points.
- Four armored analog differential inputs, 795 Kohm input impedance
- 12- to 14- bit analog-to-digital resolution, depending on scan rate
- 160 kHz sample throughput rate, so 40 KHz per channel if all four channels are active
- Programmable range per channel: ±2, 5, 10, 20, 50, 100 V full scale
- Up to 120 V rms without damage
- ±20 V dc or peak ac common mode input voltage
- 80 dB common mode rejection
- Supports ChannelStretch™ multi-unit synchronization of "similar" devices, including the DI-4208
- Adaptable low-pass filter per channel, corner frequency set as a function of sampling rate
- Seven digital ports, 25V max voltage. 4.7 Kohm pullup
- $178 (2019 Jan)
- Eight armored analog differential inputs, 795 Kohm input impedance
- 12- to 16- bit analog-to-digital resolution, depending on scan rate
- 160 kHz sample throughput rate, so 20 KHz per channel if all eight channels are active
- Programmable ranges: ±2, ±5, ±10, ±20, ±50, ±100 V full scale
- Up to 120 V rms without damage
- ±20 V dc or peak ac common mode input voltage
- 50 dB common mode rejection
- Supports ChannelStretch™ multi-unit synchronization of "similar" devices, including the DI-1120
- Adaptable low-pass filter per channel, corner frequency set as a function of sampling rate
- Seven digital ports, 25V max voltage. 4.7 Kohm pullup
- $299 (2019 Jan)
We want to be able run logging software 24/7 for days or weeks. Windows is not stable enough to run that long, and the trend in Windows 10 is to force updates such that you cannot keep a system from being rebooted for any defined time period. On the other hand, Linux PCs often run for weeks without needing a reboot, and this is even more true in the case of Linux servers and embedded systems. It's a different mindset from Windows.
- Trigger on level of any input exceeding a threshold
- Save captured data to a file with an incrementing name, a timestamp, and device configuration
- Synch the file data to the cloud
- It should be possible to create capture of "pre-trigger" data on these devices which do not natively support such a feature. This can be done by continuously sampling data and reading it into a ring buffer on the USB host.
- This moves the triggering software into the USB host
- This would make the overal function of these low-cost devices comparable to something costing much more
- Support Teensy 3.5 as a smart USB Host for the Dataq "starter kit" level of devices. Log to uSD card and over Ethernet to the cloud