I've been recording force profiles with four CZL635 micro load cells  and a USB PhidgetBridge 4-Input .
When I record the data on my Laptop (Lenovo Yoga 2017) using a python script, I get a very nice signal, with a noise level below 1N.
see Plot 1: https://ibb.co/cn1XkJ
However, plugging the USB cable into my SBC4 , running the same script and applying a similar force profile, results in a very noisy signal, with a noise level of 5N to 30 N.
see Plot 2: https://ibb.co/d5JpXy
Any idea what is going on here?
Is the supply voltage of the SBC4 USB port not constant enough (haven't been able to check)? It doesn't seem to be a problem with processing speed (see below).
Some more info:
1) The result is independent of which SBC USB port I use.
2) Processing power does not seem to be an issue. With the SBC4 I can log at about 3.5 kHz. With the laptop at about 8.5 kHz. The actual sampling frequency (change in read value) of the bridge is about 120 Hz in both cases (and as specified by Phidget).
3) The supply voltage to the SBC is sufficiently large.
4) The spike visible in plot 1 around 4 seconds is caused by an intended hit on the sensor.
Again, any help appreciated!
 https://www.phidgets.com/?tier=3&catid= ... prodid=226
 https://www.phidgets.com/?tier=3&catid= ... &prodid=35
 https://www.phidgets.com/?tier=3&catid= ... prodid=969