On Thursday, 8 August 2019 14:50:31 UTC+1, T i m wrote:
Peeps,
I would like to read the output of a strain gauge (measuring weight
(0-5kg) in this instance) from a PC as part of a general experiment
but not sure what bit does (and maybe limits), what.
I have made this sort of suggestion for a studetn project, where it can count coins going into a money box.
youtube has more than just cat videos :-)
https://www.youtube.com/watch?v=lWFiKMSB_4M
So, strain gauge (or gauges) connects to a SG amp and that turns the
output into volts?
their resistance changes and for small scale a wheatstone bridge circuit is a good idea and then that can be tunred into volts.
Then you could read said volts with say an Arduino and then have a USB
interface to PC, effectively streaming the output of the strain gauge
in ASCII (numbers) to the PC (and the rest is software etc) .
I did a simialr thing years ago using pressure sensors and a BBC computer using the analogue joystck ports as the input.
However, I understand the Arduino's only have a 10(12 with a tweak)
bit ADC and so with 10 bits I'm only going to get 1024 output values?
I;m guessing theres far better dedicated boards from somneone than an ardunio
for changing volts to a digital o/p.
eg, If that was a 1kg 'scale' then I could read around 1g increments
but if it was a 5kg scale then ~5g would be the smallest increment
(that may be fine but I am just testing my understanding here).
Or is the output of the little eBay strain gauge amps already serial
so if it was a 24 bit device (16777216) it would be resolving down to
~1/3000 of a g (mathematically at least) and so would just use the
Arduino to turn it into ASCII over a USB interface (no ADC needed)?
I know you can buy commercial strain gauge to ASCII over USB devices
but they aren't exactly cheap (~£250+).
https://uk.farnell.com/dfrobot/sen0160/digital-weight-sensor-arduino/dp/2946119?gclid=Cj0KCQjwkK_qBRD8ARIsAOteukD3iJksW0Mv WXNfIRdkp4IpZ19865gcUFIqSsfJOg-YC7SD3Z9PelEaApxkEALw_wcB&gross_price=true&mckv=YO 18ZYDl_dc|pcrid|78108376509|&CAWELAID=120173390002 973959&CAGPSPN=pla&CAAGID=14406255429&CMP=KNC-GUK-GEN-SHOPPING-2946119&CATCI=aud-308408796421
la-41477300408
One of the problems with studetn projects is that they can;t really practical make their own hardware they just ask me to order modules that they join together it's more like lego than electronic engineering.
After connecting a few boards hopefully the right way around, and nothing gets hot the rest of their time is spent coding
It's difficult to come up with an actual electronic engineering project where they use components.
Cheers, T i m