Pin 3 is connected to positive side of 12vDC power supply. Relay pin 1 is connected to positive side of fan motor. I remember seeing something about current limiting, so it may protect itself, but it may not too (and burn out if it is taking too much current. Connect the relay, fan, and 12vDC (or whatever size power supply you need for your fan motor) and the UNO board together. You may want to (carefully because it may be hot enough to burn!) check the temperature of the A4988 when the motors are running. The 3 ms pins set the microstepping mode you want, and again need to be either driven from the micro (if you want to change the microstep configuration from your program) or be tied high or low to set the microstep config you want. If you don’t connect them to a pin on the micro or a resistor or jumper to power or ground (which ever they need to work) the motor won’t run. I’d guess (without having looked at the driver schematic assuming it is available) that the pins don’t have internal pull up resistors or the pull ups are set to be disabled (reset and/or sleep asserted) if not connected. Why would this circuit need jumpers between ms1-ms2 ms2-ms3 on the drivers. It did not work initially until I added a jumper across reset and sleep pins on both the A4988 drivers.
0 Comments
Leave a Reply. |
Details
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |