I'm not sure of the answer to your second question. No extra current-dividing circuitry is necessary. As long as everything you have connected isn't drawing more than 1.5A total, your system will work fine. So you can connect your power supply to all your motors and other circuitry in parallel, and each one will only draw the power it requires at the speed/load you're running it at. 12V, but its current output will be 0A since there's nothing to draw any current.Īnything you connect to the supply that does draw current will basically use only what it needs. Without anything connected to the supply, its voltage output will be e.g. A power supply is rated by it's voltage output (which stays constant), and a maximum current capacity. Thanks to Ohm's law, current (very helpfully) doesn't work that way. If somebody knows more details about this system combination: stepper motor (ROB-09238) to easy drive (ROB-10267) or have some comments on what I wrote please let me know. I had to use the sleep mode to turn the voltage off from the motor. I would say the 330 mA rated is per phase. It gets very hot unless it is hooked to some kind of heat dissipation thing. I think that is what is going on the easydrive chip can take that current but it needs an aluminum on top to dissipate heat. Now, 12V/36 aprox 334 mA times 2 aprox 670 mA. times two I was able to read aprox 280 mA total from my power supply. I was able to see that always both set of coil are energized when pulses are not going in the easy drive. I was able to see how the signals change per set of coils when I send pulses from my Signal generator from low and high frequency (couple of HZ to 10Khz). I connected 2 LED back to back with 1K resistor each as one set of coils and another set of LEDs for the second set of coils. I did check the cables and I saw the pulses on my scope. ![]() *Example sketch to control a stepper motor with A4988 stepper motor driver and Arduino without a library.AgustinGS thank you for your answer. You can copy the code by clicking on the button in the top right corner of the code field. This sketch controls both the speed, the number of revolutions, and the spinning direction of the stepper motor. I like these assortment boxes from Amazon, this way I always have some capacitors of the right size on hand. Pololu suggests a capacitor of 47 ♟ or more (I used a 100 ♟ capacitor). To protect the driver you can connect an electrolytic capacitor between VMOT and GND. The A4988 carrier board uses low-ESR ceramic capacitors, which makes it susceptible to destructive LC voltage spikes, especially when using power leads longer than a few inches. Normally I would use 1/8 or 1/16 microstepping and connect the appropriate pins to 5V (see the table in the introduction). This makes explaining the code a bit easier. In the rest of this tutorial I have left MS1, MS2 and MS3 disconnected, so the driver operates in full-step mode. When this pin is set high the driver is disabled. The EN (enable) pin can be left disconnected, it is pulled low by default.If you are not using the pin, you can connect it to the adjacent SLP/SLEEP pin to bring it high and enable the driver. When pulled low, all STEP inputs are ignored until you pull it high. Meaning, pulling this pin low puts the driver in sleep mode, minimizing the power consumption. You can choose a different digital pin if you want, but these are the ones I used for this tutorial and the example code. The STP (step) and DIR (direction) pin are connected to digital pin 3 and 2 respectively.The GND pin (lower right) is connected to the ground pin of the microcontroller and VDD is connected to 5V.The two coils of the stepper motor are connected to 1A, 1B and 2A, 2B (see below). ![]() ![]()
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