I'm new to this forum, but am familiar with the 'duino itself (but not so much on extension shields). I need to drive two stepper motors that I already own (YH42BYGH40-402A, Seeed Studio Bazaar, The IoT Hardware enabler.). Now I have purchased a motor control shield from a local distributor (http://www.waveshare.com/motor-control-shield.htm). My problem is figuring out how to get power output from the screw terminals. I send HIGH signals to pins D2,D3,D4,D5 in sequence. I took a sample program using a stepper library for 'duino and the program works fine (I get HIGH in proper sequence on the proper pins). Does anyone have experience with this particular shield? Do I have to send a HIGH signal to two pins to get voltage between screw terminals M1A and M1B? I understand that (PROBABLY) my motors draw too much power for this driver, but I haven't connected them yet, only tested for voltage on terminals with a multimeter. ANY help will be appreciated!
Unfortunately you have the wrong motor driver.
Those motors are current controlled low-impedance steppers - you should get a couple of
DRV8825 breakouts or similar chopper-drivers for them.
Your motor need more current and active current control to work properly. Steppers with only a
couple of ohms winding resistance are not suitable for constant voltage drive, these would need
only a few volts of supply and much lower on-resistance driver, and then would only move slowly.
Chopper current control allows much zippier performance and sensible power supply requirements.
Why did you choose those motors? What are your actual requirements?