Level shift and amplifiy Pot signal

tombo · Dec 10, 2013

Hi,
no problem for off topic this is only more input for me
I have set pot min and max in my software but i thought of improove my sim a little bit.
So i think i will let my sim like it is because i use wiper motors from junkyard and do some improovings when i find the right motors.

BlazinH · Dec 11, 2013

eaorobbie said: ↑

Thanks for the explanation @BlazinH, spot on.

Another point, if your motor has big backlash don't use it, as motion will be poor or the motor might oscillate back and forth through the backlash zone, not good at all.

Backlash should be kept to a min, the big worm gears I use have a very slight backlash in them, once extended with a 65mm lever its equates to about 2mm of lost motion in 100mm of travel. Which when checked it the Jrk Utility I need a deadzone of 2, which is reasonable. But with 5:1 gearing and a good quality pot, the deadzone can be reduced to 0 and the resulting motion feel is a lot nicer, as in smoother. This is the gain in using Gearing on the pots but yes if you have too much backlash in the motors it will result in worse motion on gearing, I have to agree with that.
Sorry we got off topic a little @tombo. All important facts when selecting a motor for motion.

I would use a single turn pot as the Ard is a little slow in reading Analog inputs about 10ms delay in reading, muti turns will not really help. I would look more into the actual Ard code you want to use, plus If you use Prilads or Rufus's code you can set it up around what you have, as in set the min and max for the pots to suit the controller. Finish and test it, doesnt take long to test and go, no I will try a muti turn, experiment mate worth the learning curve.
Click to expand...

Thanks for that information on motor backlash @eaorobbie . But you have confused me with your statement of a 10ms analog read delay. I am new to arduino code but starting to pick up on it. My confusion comes from the statement in the arduino reference documents that says an analog read takes about 100 microseconds which equates to .1ms. Do you know of something I am unaware of or was this just a typo or math error? I'm not being critical but since I am learning I would like to know if I am missing something.

http://arduino.cc/en/Reference/analogRead

PS I also read that you can increase the rate by setting the ADC prescaler to as low as 16 which gives a read time of around 15 microseconds at the expense of a slight amount of accuracy.

eaorobbie · Dec 11, 2013

BlazinH said: ↑

Thanks for that information on motor backlash @eaorobbie . But you have confused me with your statement of a 10ms analog read delay. I am new to arduino code but starting to pick up on it. My confusion comes from the statement in the arduino reference documents that says an analog read takes about 100 microseconds which equates to .1ms. Do you know of something I am unaware of or was this just a typo or math error? I'm not being critical but since I am learning I would like to know if I am missing something.

http://arduino.cc/en/Reference/analogRead

PS I also read that you can increase the rate by setting the ADC prescaler to as low as 16 which gives a read time of around 15 microseconds at the expense of a slight amount of accuracy.
Click to expand...

Opps me got the decimal place wrong, silly bugger I am will correct post thanks.
But from my testing with Dashboards its still quite slow to use compared to whats on the market, its was really developed as a teaching tool, not a main stream Micro Controller that its proved its quite capable of, just a little restricted.
Thanks for picking up my (yes ,calc) error.

BlazinH · Dec 12, 2013

Thanks @eaorobbie for un-confusing me on this. Unfortunately, the next confusion for me is just around the corner!

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Level shift and amplifiy Pot signal

tombo Active Member

BlazinH Well-Known Member

eaorobbie Well-Known Member SimTools Developer Gold Contributor

BlazinH Well-Known Member