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Screen Dimming
pictures of connecting driver PWM

Attached Files Image(s)
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just thinking if you used the yellow wire from the ground of the robo tank and joined that to the ground of the driver. Do this take the yellow wire off the ground for the pwm and use a wire that has female and male like you used for the relays. put the female end on the ground pin just under where you have the pwm plugged in just like the yellow wire is now then you can take the pointed end from the other end and touch it to the ground and see if the sound goes away or not it should not hurt any thing its just an extra ground Touch it to the out negative
not the out on the inside ok
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no, change
u you also squeaks?
I wrote PWM LCD also squeaks, with dimming. Squeal of Display PCB Robo-tank coil 4,7uH :(
what is going on?
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my LCD does not squeak it is an electronic hum that you hear..
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Does it squeak when you don't have the PWM board attached? What display are you using? Is it always squeaking or only when you adjust the LED's?
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- During the adjustment LED
- Setting the PWM from 99% to 1% of the

I have a PWM driver, you can picture
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if you do not have the led driver connected and you just move the sliders on your LCD Screen you still have the squeak ??
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Hi Irass, it sounds like the PWM driver you're using doesn't like the frequency coming from the controller. In the power bar sketch at line 634 you'll see


Try adjusting the frequency to something else, maybe try 400 to see what happens.
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pwm.setPWMFreq(140); inaudible

where is the set frequency PWM LCD? because he squeaks
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Hi Irass, you're screen shouldn't squeak, what kind are you using? Are you using a 12v power supply at least 2amps?
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12V 2,5A
low efficiency? give > 3.5A
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That sounds right. There is nothing in the circuit for the display so I can't imagine the PCB causing this, I did check the boards and had no issues. Do you have another display to try? How loud is it? If its working it should be ok.
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I have only LCD 3.2" SSD1289 TFT
It will not work :(
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Sorry I don't know what to suggest, there is nothing on the board to make the display work, on the Due they connect directly. If it works it'll probably be ok.
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Cause found, the output of the power supply is connected to 12,52V Connector PCB.
Display on the PCB drop on 11,56V (a squeak).
How do I connect power to the Display PCB 12,52V (no squeak).
Why is falling so voltage? efficiency 3.5A
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so what your saying is it is the power supply is not put putting enough power?
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Hi Irass, that sounds normal. You have 12.52v going into the connector board but only 11.56v makes it to the display, that is proper. That 11.56v is then immediately converted to 5v which is used to power everything. If you have another power supply give it a try but it sounds like its doing its job.
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