Hello,
I recently decided to add a arduino to one of my projects. I picked up my parts from radio shack, the arduino starter pack and the seed studio motor shield Motor Shield V1.0 | Seeed Studio Wiki
I used a modified version of the seed studio demo code.
I do not have the specks of the motor. But it runs great with a 12v 1.5a supply.
When I used the same 12v1.5a power supply to power the motor shield the motor becomes gutless.
Ok
I guess I'm using too much juice running the electronics
So
I try it with a 12v 3.8a power supply.
Still just as gutless.
I can't even get it to trip a cheap 12v2a solenoid.
Am I missing something?
Is there a code to increase the power/ amp output of the motor shield?
You cannot get much more than 1 ampere out of the L298 chip before it starts to overheat and shut down. It is ancient technology. I recommend modern motor drivers, like those sold by Pololu.
I think you should budget your power requirement precisley, like following:
Arduino power + shield intake(normal intake with no motors running) + shield intake with motor drivers running the motors at stall current + anyother thing you are using!
Plus check the connections whether they are correct?
Thanks for the replays guys,
I checked all connectors and even attempted to bridge between motor 1 and motor 2 to add in parallel.
I had no idea this shield was such a gutless turd.
What do you recommend to bypass its wimpy ness.
I'm thinking I should just get a cheep hobbyking esc capable of 2ish amps and figure out how to run it via pwm on the arduino.
I just thought that there might be a way to ramp up the output to give it all she's got!
I read about speed codes, and something about the number 255 or 256. Does this apply to the motor shield?
The example code seems kind of limited.
I also have about 4.5 hours of YouTube video code education so........
I read about speed codes, and something about the number 255 or 256.
Thats 8-bit PWM to control speed, I think I will have to take a look finally on that shield.
For more than 1A you really need a discrete MOSFET H-bridge driver such as
the Pololu VNH5019 card. Darlington drivers like the L298 and L293 are very
wasteful of power and get super-hot.
A motor driver circuit has to cope with the max current that will flow (which
is limited by either the motor's stall current or motor supply's max current).
ESC's need the Servo library, not direct PWM. Find out the stall current of
your motor before splashing out on an ESC!
jremington:
You cannot get much more than 1 ampere out of the L298 chip before it starts to overheat and shut down.
Sure you can; you can get close to 2 amps (per channel - close to 4 in parallel mode) - but it has to be properly configured - mainly (besides the electrical connections) a fairly large heatsink (much bigger than the one on that board), and quite possibly forced air (fan) cooling.
From what I understand, the L298 (and the L293, to an extent) was originally targeted at the automotive market, for electrical actuators, in which case it was very easy to apply a large heatsink (thus no fan needed).
jremington:
It is ancient technology. I recommend modern motor drivers, like those sold by Pololu.
I suppose "ancient" in an electronics sense, if not a human since (if that were the case, I'd be ancient, am I'm only 40 years old, dammit!)...
I will agree with the need/want to use a more modern mosfet driver approach (though it's a pity from a breadboarding perspective that none of these seem to be available in thru-hole versions, outside of a discrete mosfet and DIP mosfet driver h-bridge design).
I guess I am just a curmudgeon when it comes to certain aspect of electronics and robotics; lately it seems that so much of it has become "Lego-like", with the focus more on the software aspect rather than the mechnical/electronic aspect. I see the pros and cons for both, and thus can't see either way as better or worse...
This is how you can increase the potential of your L293s (see attached image)
Stacking all the way!
I suppose "ancient" in an electronics sense, if not a human since (if that were the case, I'd be ancient, am I'm only 40 years old, dammit!)...
I've got you beat by a quarter century. Be patient, you'll get there 
or is it :~
I will agree with the need/want to use a more modern mosfet driver approach (though it's a pity from a breadboarding perspective that none of these seem to be available in thru-hole versions
I use Pololu's little breakout boards for breadboarding., such as DRV8833