Raspberry Pi 3B+ dual motor control question

Hi, I want to ask questions about dual motor control by raspberry Pi 3B+. here is reference (we do it as a school assignment)

and we try to connect the wires as the photo below and run the motor by two types of algorithm below. But it doesn’t work.

first algorithm

second algorithm

algorithm reference

we want to know why it doesn’t work. is the problem caused by incorrect connection of wire or wrong algorithm? plz help

Hello.

It looks like the driver you have is not manufactured by us; we have only ever made our DRV8825 drivers with purple PCBs. That makes it difficult to say for sure what might be causing the problem, and we cannot help you troubleshoot it since it is likely different than ours. However, if you decide to test out our drivers by ordering them from us or one of our authorized distributors and run into issues, please let us know.

By the way, in general, breadboards cannot handle very much current, and the thread you linked to was resolved by identifying a bad connection. With that in mind, one troubleshooting suggestion regardless of your particular driver would be to look at all your setup with oscilloscope (or a multimeter if you do not have access to one) to verify that things are connecting and operating the way you expect them to.

- Patrick