DRV10983: Problem with reading and writing to the DRV registers.

Hi Muthamilselvan,

All registers are accessed same way. Adress 0x10 to 0x1E are read only. Can you check the first I2C word (Adress: R/W) and second read if the register address.

About I2C bit rate there is no data in the data sheet but other products in this family has information. I will confirm about the data rate support by next week

Thanks and Best Regards,

Venkatadri S

Hi Venkatadri,

Thank you so much for your reply.

I have verified that the first word is I2C address then the Registers address to read. Read is working fine for the EEPROM Registers from 0x20 to 0x2B. Status registers always read zero. For example, SupplyVoltage Register is 0x00 even though Vcc is 24 V. 

Please have a look at the Register contents read back from the DRV10983. New problem what we face is, after configuring all these, if we set the speed through SpeedControl registers, DRV does not generates output voltage.

This IC works fine at 100 Kbps.

Best regards,

Muthamilselvan N

Hi Muthamilselvan,

Speed command sequence should be like mentioned below (Command value is example for 100% speed)

1. Send speed control with command 0x81 to Register address 0x00  (In command 0x81 has Most significant Bit "Override" )

2. Send next send command 0xFF to Register address 0x01

This sets speed to 100% with Override command (0x81)

Thanks and Best Regards,

Venkatadri S

Hi Venkatadri,

For Speed command, we need to send 0x81 to 0x01 and 0xFF to 0x00 for full speed, right? As mentioned in the register map. 

I have written this still is does not drive the motor.

Best regards,

Muthamilselvan N

Hi Muthamilselvan,

Sorry for typo error. You are correct.

Can you check if there are any fault and it is not allowing to spin motor? Supply voltage updates to 0x1A when motor start running.

Better once connect though GUI verify the tuning. Write the tuning to EEPROM. On your host just test speed command.

Thanks and Best Regards,

Venkatadri S

Hi Venkatadri,

I have read the Fault Code Register at 0x1E. It is reading as 0x00. We don't understand what the possible fault could be. I have verified the I2C line for read/write operations. Communication happens properly. Still the controller does not generate output.

Best Regards,

Muthamilselvan N

Hi Venkatadri,

We are controlling the speed through I2C. Then, can we leave the SPEED Pin of the DRV10983 to be floating or do we need to either pull up/down?

Best Regards,

Muthamilselvan N

Hi Muthamilselvan,

If you are configuring SLEEP mode then keep speed pin High to wake it up and then I2C command can be sent.

In general keep speed pin to a stable level. Please refer to the note in the data sheet.

Thanks and Best Regards,

Venkatadri S

Hi Venkatadri,

I have kept the SPEED Pin HIGH and tested. Still, I'm facing the same issue.

Best Regards,

Muthamilselvan N

One more issue what we face is, DRV10983 and nuvoton MS51FB9AE MCU communicate each other only when the Logic Analyzer is connected on the I2C lines. When we remove the Logic Analyzer, I2C communication does not work. Kindly, help resolve our issues as soon as possible.

Hi Muthamilselvan,

Please probe I2C lines on the oscilloscope with high resolution. Verify if the I2C pulses are not distorted (clock/data)

The pull up resistance has to be adjusted based on the board capacitance.  Please refer to this application report I2C Bus Pull-Up Resistor Calculation

Please verify if the pull up resistance is as per recommended values.

Thanks and Best Regards,

Venkatadri S