PCB problems

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Paulmchurd
Posts: 227
Joined: Sun Dec 10, 2017 4:39 pm

PCB problems

Post by Paulmchurd »

Hello,

I've been using a development board to make a ESC circuit. When I connect the PWM inputs from the Reciever the motors become uncontrolable and spinning constantly.

When plugging in the arduino to check the PWM it gives readings of 5000-10000mS. Then without the components mounted on the board they read. 1000-2000mS as they should.

Is there some sort of interference from the development board causing mixed messages/over vaulting the RX.

I'm totally confused by it all...
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peterwaller
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Re: PCB problems

Post by peterwaller »

You have to be careful the signal coming from the receiver is a form of pulse width modulation but is not what is required by the motor drivers.
The pulses coming from the receiver outputs should be between 1 and 2 ms.
The controller needs to measure these to determine the speed required, 1 ms full reverse, 1.5 ms stop and 2 ms full forward.
This has to be converted to wave form that the motor drivers require and this varies depending on the drive chip used.
Many just have two inputs IP1 and IP2 with both high or both low there is no drive to the motors.
With IP1 high and IP2 low you get full speed forward.
With IP2 lhigh and IP1 low you get full speed backwards.
So to control the speed forward you make IP1 high and switch IP2 on and off rapidly. The longer IP2 is low the faster the motor will go forward.
To control the speed backwards you make IP2 high and switch IP1 on and off rapidly. The longer IP1 is low the faster the motor will go backwards.
I hope this helps.
Paulmchurd
Posts: 227
Joined: Sun Dec 10, 2017 4:39 pm

Re: PCB problems

Post by Paulmchurd »

Never mind I’ve figured out my problem. My arduino seems to have a faulty voltage regulator. It wasn’t regulating the 7.2 input down so the logic levels were way to high....now the arduino has a steady 5v it works fine, I think... fixed for now any way haha.


Thanks Peter for the reply
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