MCT8316AEVM: Board disconnects from GUI when motor start spinning

Kaijia Chen

Part Number: MCT8316AEVM
Other Parts Discussed in Thread: MCT8316A,

Tool/software:

I am using MCT8316A_GUI v1.1.4 to set up the MCT8316AEVM board for controlling a VCI 11000 KV Motor VCI SPARK 1102 MOTOR-11000KV/13000KV/21000KV(2PCS) - VCI HOBBY. With the default settings, the board does not spin the motor, so I tried inputting motor's parameters and increasing the PWM frequency to troubleshoot. As I gradually increased the frequency, the motor was able to spin, but as soon as it started spinning, I encountered connectivity issues—the board automatically disconnected from the GUI. Attempting to reconnect did not resolve the issue, as the connectivity problem persists whenever the motor is running. I have observed this same behavior with several high KV drone motors: increasing the PWM frequency allows the motor to start spinning, but the board disconnects from the GUI as soon as it does.

I have attached the motor parameters, hardware board connection setup, and a screenshot of the connectivity issue. Could you please advise on possible causes for this issue? Thank you.

4 months ago

0 Venkatadri Shantaram84961 4 months ago

TI__Mastermind 26012 points

Can you monitor AVDD, Buck output, VCP?

Is there any thermal shutdown or overloading occurring?

What is the load when this disconnection happens?

Thanks and Best regards

Venkatadri S

0 Kaijia Chen 4 months ago in reply to Venkatadri Shantaram84961

Prodigy 30 points

Hi Venkatadri,

Thank you for your response. Yes, I was monitoring the FAULT STATUS, and it seems like it shows error Bulk_regulator_undervoltage. The motor was running with no load, and the current from the power supply stayed below limit, so I did not observe any signs of overheating. The voltage and current are all set based on the motor's spec sheet.

On some occasions, the motor did start spinning without disconnected from the GUI, and the Status indicated "motor_start," but there were no readings for any of the other parameters, and I wasn't able to adjust the I2C speed Command (regardless of percentage, the motor spin at the same speed) and get any reading from the virtual oscilloscope.

Best regards,

Kaijia C

0 Venkatadri Shantaram84961 4 months ago in reply to Kaijia Chen

TI__Mastermind 26012 points

Hi Kaija,

I will look into this further and get back to you.

Thanks and Best regards

Venkatadri S

0 Kaijia Chen 3 months ago in reply to Venkatadri Shantaram84961

Prodigy 30 points

Hi Venkatadri,

I just wanted to follow up to see if you have any update. Thanks!

Kaijia C

0 Venkatadri Shantaram84961 3 months ago in reply to Kaijia Chen

TI__Mastermind 26012 points

Hi Kaijia,

One question, do you record at what motor speed (frequency) I2C connection loses?

Can you probe VBK test point and see at any point buck voltage is dropping?

Thanks and Best regards

Venkatadri S

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MCT8316AEVM: Board disconnects from GUI when motor start spinning