I have a bunch of these that has been laying around for ages with the DIP version drivers of ULN2003, but I have never tested them. So I connected a STM32F030F4 dev board to the ULN2003 driver and tested a 4 step and 8 step algorithm.

I have used quite a lot of steppers and servo’s before, so I was a bit surprised. It uses about 4ich second on one turn, so it’s not the fastest, but it is incredible strong. The 8 step algorithm draws 130mA on the motor + driver and is absolutely soundless using 4096 steps on a 360 degree trip. At the cost of ca 1.- GBP on ebay I am actually impressed and I fully understand why these are so popular.

I can drive one of these using the micro PWM driver, but I will return with a few more specialised driver boards that support 1-2 motors and 1-2 endstops or position encoders.

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