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Itsy Bitsy 32u4 3v 8mhz
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Itsy Bitsy 32u4 3v 8mhz

by Andres_r35 on Wed Mar 24, 2021 8:00 pm

Hey guys, so I am trying to go from using an UNO to an ITSYBITSY. I have a L293 motor controller a buck converter, and a radio plugged in. I am having trouble with getting the motor moving when using the itsybitsy. I have an oscilloscope to see if the outputs are even working and looking the same, and they look the same to me besides the logic voltage it gives out.
Screenshot 2021-03-24 165335.png
Screenshot 2021-03-24 165335.png (64.16 KiB) Viewed 111 times
This picture that I attached is the first pin of the L293 and I am sending it an analog write of 230. One of the pins is low and the other pin is high at 3.3v. This is all using the itsy bitsy, but the motor won't budge and I have no clue why. I am also giving the L293 power from the buck converter, which is supplying around 3.6V. I would really appreciate any help anyone can give.
https://www.ti.com/lit/ds/symlink/l293.pdf
according to the datasheet, this amount of voltage should be good enough to get the motor running right?

Screenshot 2021-03-24 170128.png
Screenshot 2021-03-24 170128.png (322.67 KiB) Viewed 110 times

And then this is the first pin of the L293 on the Arduino Uno test. The voltage is higher, and the analog write was at 220. Again I used the buck converter to give the L293 power and had the same motor plugged in. The only difference is the UNO sending the code, but it gets the motor running?

Andres_r35
 
Posts: 1
Joined: Thu Oct 29, 2020 11:22 pm

Re: Itsy Bitsy 32u4 3v 8mhz

by upnorthtek on Tue Apr 06, 2021 6:43 pm

Looking at the O-scope image. The motor refence point is at 3.6v. for the motor to have full motion (rotation). The L293 should have a 0v dc refence point. Your capture shows a deep negative value with a small positive voltage swing. read the data sheet for the L293 and note the voltage for the + and - values. to get the motor rotation, the motor will need a reference point for the positive an negative sinewave alternations.

upnorthtek
 
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Joined: Fri Mar 27, 2020 4:15 pm

Please be positive and constructive with your questions and comments.