LabVIEW

cancel
Showing results for 
Search instead for 
Did you mean: 

Set PWM line from DAQ card High Z

Hello everyone. I hope someone can help me. I am trying to program a motor driver and then use it with pwm mode. The problem that I2C lien SCL for programming is done with PMW pin on the chip, so this pin is used both for programming and for PWM input. I did some test and found out that if the both PWM and SCL are connected at the same time, I can not program the chip. Because when PWM input is not connected and I program the chip, the motor will start with 100% duty cycle and if after programming I connect PWM input with 50% duty cycle , the motor will go to 50% duty cycle. I think that I need to initialize PWM and set the low to Hi-Z before programming and after programming set it to push pull but I dont know how to do it. In the attachment I added a block that I am using to initialize and create PWM signal, I am not sure how I can modify it so my problem will be solved. Thank you 

0 Kudos
Message 1 of 3
(48 Views)
You have a hardware design problem. You will need different hardware and software will not fix it.

"Should be" isn't "Is" -Jay
0 Kudos
Message 2 of 3
(24 Views)

Typically DAQ don't have the feature to HiZ the PWM channel.


Use an additional digital line to control a switch (MOSFET, BJT or relay) whether to connect the counter output (PWM) to your motor driver.

Santhosh
Soliton Technologies

New to the forum? Please read community guidelines and how to ask smart questions

Only two ways to appreciate someone who spent their free time to reply/answer your question - give them Kudos or mark their reply as the answer/solution.

Finding it hard to source NI hardware? Try NI Trading Post
0 Kudos
Message 3 of 3
(18 Views)