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Step 3Motor Controller
The motor controller I built for this robot is based off the L298HN Dual Full Bridge chip. To use the chip, I followed the guide here. To start out, I placed all the components on a piece of perf board, to figure out the layout. With this chip, each motor requires three inputs to work: an enable signal and two input signals. The enable signal is used to control the motor speed with PWM, but since I did not need to control PWM, I just wired all the enable pins in parallel to a 5V line when I hooked the controller up to the Arduino. Once I figured out the layout, I soldered all the components in place, and made connections with 22AWG solid core wire. Finally, I spread some thermal paste on the back of the L298's, and screwed on the heatsinks. The particular heatsinks I used were made by cutting in half a northbridge heatsink from a computer motherboard, and drilling and tapping a hole for the screw. They are probably much larger than needed, but there is no harm in having over sized heatsinks. A higher resolution image of the labeled board can be found here.
When finished, this motor controller should be able to bidirectionally control 4 DC motors at up to 2A each (probably 2A continuously, because of the size of the heatsinks). As you may notice, this leaves me one motor short. My original design used a servo to actuate the spine, but I had to change my design to using a DC motor. To power it, I wired my third L298 chip to a molex connector (so I can disconnect the motor) and soldered on wires for all the connections. It does not look as pretty as my controller on a circuit board, but it works.
When finished, this motor controller should be able to bidirectionally control 4 DC motors at up to 2A each (probably 2A continuously, because of the size of the heatsinks). As you may notice, this leaves me one motor short. My original design used a servo to actuate the spine, but I had to change my design to using a DC motor. To power it, I wired my third L298 chip to a molex connector (so I can disconnect the motor) and soldered on wires for all the connections. It does not look as pretty as my controller on a circuit board, but it works.
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Mar 26, 2012. 3:59 PMGENERALCHAOS
says:
u can use transistors to control the L298HN like the L293D ?
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16
Mar 26, 2012. 4:17 PM
Technochicken (author)
says:
Technochicken (author)
says:
You can control the L298 directly from the arduino, without extra transistors.
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Mar 26, 2012. 5:31 PMGENERALCHAOS
says:
i was asking can it work im making a EAGLE PCB atm i have it done on the proto but i messed it up wired it wrong i have 3 and 1 is im use to control two Honda AC cooler door servos for a solar sun tracking
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16
Mar 26, 2012. 5:42 PMTechnochicken (author)
says:
Technochicken (author)
says:
I'm not sure why you would want to use a transistor to drive it. Rather than using a transistor, why not drive the l298 with whatever source you were going to use to drive the transistor? If it can output enough current to drive a transistor, it can definitely directly drive the signal for the l298. I suppose it would work though (although I am not sure what part you want to control with the transistors)
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Mar 26, 2012. 6:18 PMGENERALCHAOS
says:
it feels saver with the resistor controlling the 5 volts to CHIP KIT MAX32 the 5 volt gonna be regulated to power the chip kit and the transistor im just wanted to set it up like it make me feel saver theres another 1 to it a 2 pin and leave me with extra pin to control more stuff if u nee to
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