Mwahaha I always knew I would find something useful with this littlebits…
Testing how far down I have to push z until it registers.
Not looking good… Though it did registered after certain force and spits out number, the numbers are erratic not sure if it is because of the littlebits display or what…
Have the pad area pressing on the FSR be a little smaller. I find larger pads need more pressure to register the touch. Something like 50 to 60% the actual size of the FSR
preload set screw on the back of the FSR mount, to get the thing near a reliable reading pressure? then contact pushes the value into the range needed? maybe? ima big fan of preloading…
Thanks both suggestion seems good. I’m going to change some of the design.
I do wonder, on a scale of 0-100 at which point the trigger will happen? The rugular lever limit switch doesn’t seem to have this range issue…
You should be pushing on a small point, not over the entire surface of the FSR. You may also want to put the hot end on a longer flex arm so that a larger linear motion equates to a smaller angular motion.
To adjust the amount of force needed to trigger the FSR, just change the value of the fixed resistor.
The guys said it but a force applied at a smaller surface area would be more reliable.
…
I didn’t want to make the arm longer but instead I mount the FSR at angle to ease the force transfer
[update] @AlohaMilton pre loading the FSR seems to work more stable. It was squeezed to about 90% and all it takes to get to 92% is just a light tap on the nozzle. I’m hoping that would be enough to register as z trigger
@Whosa_whatsis I’m going to have to figure out how to change the FSR fixed resistor value if there’s such setting in replicape… @Elias_Bakken
You don’t want to keep the FSR under pressure, it will break down.
The resistor value isn’t a setting, it’s a physical resistor. How did to attach the FSR to the board?
I haven’t wire the FSR to board yet still waiting for molex microfit
So I can’t do a real test yet. But it seems without constant pressure, getting the littlebits reading from 0℅ to 30℅ takes quite a lot of deflection…
Do you even know if the thing measuring voltage or resistance?
When you hook it up to the controller board, you’ll build a voltage divider with it and a fixed-value resistor. The voltage out of the divider will be determined by the ratio of the values of the two resistors, so you’ll be able to change the amount of force required to trigger by changing the other resistor.
As usual, littlebits are completely worthless for learning anything about how actual electronics work.
