Problem with PWM at pin 25--> BLE modules broken

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Anonymous
Not applicable

Good afternoon,

   

We are using CYBLE-214009-00 to run a turbine with the sensorless motor control method for a three-phase permanent magnet motor and we run through some trouble with the micro-controller.

   

First of all, attached you can find a diagram of the connections.

   

In a sensorless control strategy you need to use PWM in the top drivers of the three branches/phases (A, B and C). After some time of testing and some progress (managing to operate the motor) the system stopped working because one phase was failing (phase C) and we found out that the impedance from pin 25-TOP_C to GND was in the range of 200Ohms while the impedance of TOP_A and TOP_B to GND was in the range of MOhms. After desouldering the module we found out that the impedance was still much lower than it should be in TOP_C.

   

It happened the same with the first PCB we tested but much sooner so we thought it was a problem of the soldering of the module but now we know the module also crashed in the first PCB.

   

We would really appreciate if you could help us find out the cause of this trouble.

   

Thank you,

   

Arnau Ibarz Claret

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rola_264706
Level 8
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I can't make a guess as you have not provided a complete schematic of your design.  How is the motor connected?  What voltage is it running at.  ? What kind of emf protection are you using ? Why are you using such a small device from first glance it looks like you are running out of resources. Also please send the complete program so we can check it. To do that click on file and then click on create workspace bundle and see it on a new comment by clicking on add Attachments.

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Anonymous
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Thank you for the fast answer bobgoar.

   

I'm attaching a more complete diagram of the connections.

   

We are not using emf protection.

   

We are using this device because we wanted a small solution that combined bluetooth and motor control, do you think we have better options?

   

I'm sorry but I can't provide the complete program as it is confidential.

   

We think that there may be some trouble related to using pins 25 and 15 for different PWM. Do you think that could be the case?

   

Many thanks,

   

Arnau

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rola_264706
Level 8
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I would put a scope on the lines and check for noise spikes.  Maybe an interface chip between the PSOC and your circuit.

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rola_264706
Level 8
Level 8
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Also try it on an non Ble part like a PSOC 4  or 5lp kit to insure it works with those and if it does it could be your part is too small for the design.

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Anonymous
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Thank you bobgoar, we might what you are proposing.

   

On the other hand, is there any problem with using pins 25 and 15 for different PWM?

   

Thanks,

   

Arnau

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