I just bought a micro DSMC and was eager to get started messing around with it and a Basic Stamp IIsx. I checked and double checked my connections, and just as a test loaded the small program at the end of the documentation. I was disappointed to find no response from the motor I had connected.
I am using a Board of Education with the small breadboard used for making the circuit. I have a lab power supply to provide 9 V to the motor, with the + of the supply going to Pin 1 on the DSMC, and the - of the supply going to Pin 2 on the DSMC. Pin 2 is also connected to Vss on the BOE. Pin 3 on the DSMC is connected to Vdd on the BOE. Pins 4 and 5 are connected to the reset and control lines from the Stamp, and Pins 6 and 7 are going to the motor leads. To me, this seems correct, based on the connections shown in the documentation.
I did a little investigating with a multimeter, and found that all the correct voltages are present at the appropriate pins (9 volts at Pin 1, 0 volts at Pin 2, 5 volts at pins 3, 4, and 5), but found that Pins 6 and 7 are both receiving about 0.22 volts, with 0 volts across the motor leads themselves (I would expect something slightly less than 9 volts).
What gives? Did I somehow blow the DSMC? The connections seem straightforward to me, but somehow I’m missing something.