Cytron Technical Forum

Hello,

I am trying to use a Heng Long 1:16 Panzer IV Tank model as a wheel base for a robot. It comes with a 7.2V power supply(battery). The micro controller i am using is a MEGA Arduino.

The motors draw quite a bit of current. Each of the two bidirectional motors for the treads use about 3amp. So i think that the best solution is to buy two times the MD10C http://cytron.com.my/viewProduct.php?pcode=MD10C&name=Enhanced%2010Amp%20DC%20Motor%20Driver.

As is am just starting out with Arduino I am a little bit confused on how to connect the MD10C and how the software would look like. Is there a firmware or example code availible? So far I have used Adafruit's Motor/Stepper/Servo Shield for Arduino http://www.adafruit.com/products/81 which comes with clear instructions and demo code - however it can only support 600mA - which is way to little for my needs.

Any help is appreciated!

Thanks

Basically is using PWM and digital output only, the program is similar I think, try to hook up something and modify the code.

How can I get the neccessary 12V for the MD10C out of the 7.2V accu pack?

tobytobsen WROTE:How can I get the neccessary 12V for the MD10C out of the 7.2V accu pack?

Opss... din notice you are not using 12V after all

Boosting the 7.2V battery is possible but is not advisable as there will be more work and extra cost. Is it a must for you to use MD10C, or 7.2V? You can choose to tab 12V from 12V adapter just to make sure 12V to MD10C is there.

Yet, you can always try to power MD10C with 7.2V and see whether it can work, I am not sure how Cytron design that driver, so try is a good way to know the answer

tobytobsen WROTE:How can I get the neccessary 12V for the MD10C out of the 7.2V accu pack?

What is the capacity of your 7.2V battery and how long do you intend to run your robot?

Allen

It's the original supplied Battery - i think its a 2000mAh NiMH.
When then tank is in normal remote toy mode it runs for about 45 minutes.

Actually I wanted to propose using 2x LM2577 to step up the voltage from 7.2V to 12V. But from my experience, using LM2577 at its max current (3A) would make it very, very hot and will shorten its life and the 100uH coil will even melt. And the time left to run your robot would be reduced to 14.4 minutes if the conversion power loss is 20%, provided my calculation is correct.

So I guess a better option is to get a battery with higher voltage e.g. > 11.5V (Expensive) with same A/H rating,

OR get the 12V from a PC ATX PSU. Cytron has a breakout board for this PSU and is very well designed. The +12V has a capacity of 14A (though I know it may not be true) but at least 10A should be there. And you dont have to worry about the +5V for your MCU.

BB-ATXRA - Breakout Board ATX Right Angle
http://cytron.com.my/viewProduct.php?pi ... !yn0flxwc=

Allen

ABSF WROTE:Actually I wanted to propose using 2x LM2577 to step up the voltage from 7.2V to 12V. But from my experience, using LM2577 at its max current (3A) would make it very, very hot and will shorten its life and the 100uH coil will even melt. And the time left to run your robot would be reduced to 14.4 minutes if the conversion power loss is 20%, provided my calculation is correct.

So I guess a better option is to get a battery with higher voltage e.g. > 11.5V (Expensive) with same A/H rating,

OR get the 12V from a PC ATX PSU. Cytron has a breakout board for this PSU and is very well designed. The +12V has a capacity of 14A (though I know it may not be true) but at least 10A should be there. And you dont have to worry about the +5V for your MCU.

BB-ATXRA - Breakout Board ATX Right Angle
http://cytron.com.my/viewProduct.php?pi ... !yn0flxwc=

Allen

Allen, good suggestion on the booster. Never use that before, but want to try it one day.

BTW, the 12V required on MD10C is just for operation, is not for motor power. According to the User's Manual, this driver require minimum 12V to operate, it can either be from power to motor, or from microcontroller or controller. There is jumper to select where you get this minimum voltage from So if you are using 12V to supply the motor, you can select VIN (Vmotor), and let say you want to drive motor with 6V only, no problem, you can still supply this 12V for driver from controller site or external, but it is very small current (not sure how much, they din state it). So your proposal of boosting the voltage is still applicable

On the other hand, did you get the BB-ATXRA? Went through the article using it, seem to be interesting. Wanted to try it, but I malas to get an ATX power supply from computer shop. Seem to be useful as you said, 3.3V, 5V +-12V, high current. They should put a few fast blow fuse to protect the track OK, will try one day when I get an ATX power supply. If you have try, share with us

robosang WROTE:Allen, good suggestion on the booster. Never use that before, but want to try it one day.

Yes, they are good stuffs. You can also replace the 7805 with LM2575-5V and dont need any heat sink, just a 330uH coil and a 1N 58xx diode. I am using them in high input DC (24V) projects.

robosang WROTE:BTW, the 12V required on MD10C is just for operation, is not for motor power. According to the User's Manual, this driver require minimum 12V to operate, it can either be from power to motor, or from microcontroller or controller. There is jumper to select where you get this minimum voltage from So if you are using 12V to supply the motor, you can select VIN (Vmotor), and let say you want to drive motor with 6V only, no problem, you can still supply this 12V for driver from controller site or external, but it is very small current (not sure how much, they din state it). So your proposal of boosting the voltage is still applicable

On the other hand, did you get the BB-ATXRA? Went through the article using it, seem to be interesting. Wanted to try it, but I malas to get an ATX power supply from computer shop. Seem to be useful as you said, 3.3V, 5V +-12V, high current. They should put a few fast blow fuse to protect the track OK, will try one day when I get an ATX power supply. If you have try, share with us

I didnt know that. I thought it was for running the 2 motors rated at 3A each.

No I haven't got them yet but I will get him on my next order from cytron.... togrther with an Arduino maybe. I am familiar with ATX PSU and I have repaired a few of them. I also has the schematics of it. Very useful if you want to test op-amp circuits or XBee as the +/- 12V and 3.3V are there.

Allen