Hi Steve!
I'm in the process of building the SP11 clock. I purchased all the parts except the motor driver, which I was not able to find locally. I have a TMC2209 from another project. Do you think that I could use a 2209 instead of 2208, without modifying the Arduino code?
Thank you!
Thanks for the feedback. I used to think the 2209 was a superset of the 2208, but your data shows otherwise. I still don't know why it doesn't work. Maybe it needs to be configured through the SPI port before the STEP/DIR pins are enabled. Many diagrams show jumper wires to the top pins to enable extra features.
Good to hear you got a working clock driver. Testing it on the bench allows you to see how it should work. And you can easily adjust the motor current to be as low as possible. The clock needs very little power.
Steve
It is likely that the TMC2209 will work, however I have never tried it. The clock doesn't need to use any of the advanced features of either chip. It only uses direction, step, and the frequency divide pins.
Google shows the following differences:
The 2209 is targeted for higher current. The current sense resistor is 0.2ohms instead of 0.3ohms. We intend to use the driver at the lowest possible current setting. The clock should still work with 50% higher motor current.
The 2209 has a larger heat sink. The case is designed for the 2208 size heat sink, although the clock should run just fine without a heat sink since we are running it at the lowest current setting.
The 2209 appears to add two additional pins in the center. They may need to be removed.
There is very little harm in trying the 2209 since you already have them. You can test it outside the clock to see if the motor spins smoothly. Adjust the current to the lowest possible stable setting. The current needs to be low enough to run off the 5V USB power supply. Hopefully, the 2209 supports 5V operation similar to the 2208. You should be able to hold the motor shaft and stall the rotation.
Please report your findings if you try it.
Steve