About a year ago, I decided to build a robotic platform to achieve some experimentation with assorted robot advice systems. My objective was to get the platform up and running with a minimum of fuss. To do this I decided to use as many off-the-shelf components as possible.
For my microcontroller, I decided upon the Parallax Bs2. I already had one lying around, so the cost was moot. I'm not against other controllers and should my experimentation prove fruitful, the resulting task will verily need a larger, more capable controller.
My mobile platform was a recycled remote operate car liberated from Radio Shack many years ago. This platform has track drive with each track driven independently by a isolate Dc motor. As this is a small platform, I could comfortably keep my power requirements to colse to 2 amps max at 9 volts. Holding this in mind, I first decided to build a integrate of H-Bridge circuits out of assorted components. I verily have what I needed in my junk box to do so. However, my objective was to use off-the-shelf components. I reconsidered and decided to find an affordable, pre-built alternative.
The Basic Stamp has quite a few usable I/O lines, but I verily wanted to keep as many free as inherent for my advice experiments. I decided that the best course was to find an provocative controller which I could command serially. I searched the usual sources, but I couldn't find one I belief was reasonably priced. I always buy in minimums of two. That way, just in case I destroy one, I have a spare. The minimum price I found from the usual sources was , so two were going to cost - too much!
That's when I turned to eBay. Lo and behold, my search was successful. I found the Dmc-1 Serial Dual Motor Controller.
The Dmc-1 is a dual motor controller from Ims Llc that can be controlled with accepted 5V Ttl signals at 2400 - 19200 baud or by I2C protocol. Each controller can handle 1.2A per motor continuous (3A peak) at 2.5 - 15V. The best part is the price: .95 each!.
When I received my controller, I was shocked at the size. This thing is small! So small that I was worried it wouldn't be able to withstand a continuous current of 2.6 A (two motors).
First, I read the documentation. The Dmc-1 has nine association pins. A safe bet and negative association for each of the two motors consumes 4 pins. Scl and Sda pins for communicating with the controller using serial Ttl or I2C accounts for two. One pin for 5V logic supply, one pin for the 2.5 - 15V motor supply and one pin for ground rounds out the complement of nine.
Connecting the Dmc-1 to my Bs2 and the motors on my platform was a piece of cake. Plugging in the controller to my breadboard, I used the regulated 5V supply from my Bs2 protoboard to supply the logic. I related the safe bet and negative leads from the motors to the accepted rows on my breadboard. I used a 9.6V Rc battery to supply the motors. I premium two pins from my Bs2 to retell with the Dmc-1 and related a base ground for the controller and motor supply. Now I was ready to retell with the controller.
Although the hand-operated is more than adequate, Ims, Llc supplies a sample Bs2 operate schedule to get you started. I fired up the Basic Stamp editor, loaded the program, made a few adjustments on pin assignments, compiled the program, downloaded it to the stamp and it worked!
Of course, I had to tweak the code for my application, but it was easy to do and the controller worked flawlessly. Earlier I said I was worried that the controller might need a heat sink. I am happy to description that while my use, the controller doesn't even get warm, so I think this was an unnecessary concern.
Conclusion
The Dmc-1 is a well made, inexpensive, flexible dual motor controller for small platforms. If you are in need of just such a controller, I suggest you check it out. It will verily take more time to build an H-bridge from your junk box and you won't have the flexibility of a serial controller. I haven't had the chance to test the I2C capability, but plan to do so in the not to distant future.
reasonable Controllers for Small Dc Motors - Introducing the Dmc-1