Motor Driver fries on arduino reset/upload

hello,

i use HG7881 drivers and they keep frying they control a dc motor that goes forward/backward, I added a linear pot and 2 optical sensors to detect the motor position so arduino reverse the motor direction

but once I program the arduino, the driver can stay in a ON state with stalling motor and then fry

also, if the mecanic gets blocked or the sensors stop working, arduino cant detect it and the driver keeps giving current on stalling motor wich the driver fries again

tough case, and I have no idea (without using CP's or fuses) how to deal with this I would say that when motor is runing it seems to draw +-600mA, on stall it goes up to 2A

thanks

I think you'll need to provide a full schematic of how you have it connected (including your pot and sensors) before anyone is going to be able to guess what's going wrong.

That $2 motor driver can handle only 800 mA per channel. You need one that can actually handle the motor current, like this: http://www.pololu.com/product/1110

Note that brushed D.C. motors briefly draw the stall current when starting.

jremington: That $2 motor driver can handle only 800 mA per channel. You need one that can actually handle the motor current, like this: http://www.pololu.com/product/1110

Note that brushed D.C. motors briefly draw the stall current when starting.

well I draw 600mA so it should be fine also Imax is 2000mA,

the problem is that the IC have no T° protection so I would need to have something that cut the current when it is to high for too long

Even if I use another Ic, then the motor could fry

the issue is about having Arduino unresponsive while driving a dc motor that could stall it is bound to burn without protection

the Qik seems to have a timeout/serial error protection but It wont protect the circuit on too long High peaks currents

KenF: I think you'll need to provide a full schematic of how you have it connected (including your pot and sensors) before anyone is going to be able to guess what's going wrong.

??? come on, you obviuosly did not even read my question (or maybe I asked it wrong)

rompelstilchen:

KenF: I think you'll need to provide a full schematic of how you have it connected (including your pot and sensors) before anyone is going to be able to guess what's going wrong.

??? come on, you obviuosly did not even read my question (or maybe I asked it wrong)

Or you could just take your chances. Some people like to live life on the edge :p

KenF:

rompelstilchen:

KenF: I think you'll need to provide a full schematic of how you have it connected (including your pot and sensors) before anyone is going to be able to guess what's going wrong.

??? come on, you obviuosly did not even read my question (or maybe I asked it wrong)

Or you could just take your chances. Some people like to live life on the edge :p

??? I dont follow you :-)

the problem is that the IC have no T° protection

The Pololu driver chips do have over temperature protection. But that doesn't help if the driver isn't rated to handle the actual motor current (which yours is obviously not), because it overheats and shuts down.

The chips he's using are rated for 1.5-2A peak, 800ma continuous. But when stalled, the motor pulls 2A continuously, hence it's burning out the chip. The chips should be sufficient if controlled correctly, but are very close to their limits, so you have very little room for error with them. I'd recommend a beefier driver, or at least sticking a little heatsink onto the ones you have.

In any event, why the hell are you running the motor driver when arduino program isn't running?! At the very least, put pulldown resistors on the input lines for the chip (or pullup - per datasheet, if both are high, or both are low, nothing gets driven) so when the board resets, the inputs will both go low and it won't try to drive anything. Also, make very certain that your code is careful about not driving the motor when it's not moving (particularly if you continue to use these barely-adequate-if-nothing-goes-wrong drivers)

Hi, Can you please post a copy of your sketch, using code tags. Can you please post a copy of your circuit, in CAD or a picture of a hand drawn circuit in jpg, png or pdf? Can you please post a picture of your project.

WHY??? You have the project infront of you, we don't. You know how it is wired, we don't. You know how you are powering the motor and arduino, we don't. You know how you are outputting digital logic to the H-Bridge, we don't.

A picture, a circuit diagram and a sketch is worth a thousand words and can save a thousand ill informed posts.

For us to give you anywhere near accurate and usefull help you need to help us too. We are at post #9 and still we know nothing about the motor voltage or how you have connected the H-Bridge to the arduino.

Tom.......Hope to help mate...... :)

TomGeorge: Hi, Can you please post a copy of your sketch, using code tags. Can you please post a copy of your circuit, in CAD or a picture of a hand drawn circuit in jpg, png or pdf? Can you please post a picture of your project.

WHY??? You have the project infront of you, we don't. You know how it is wired, we don't. You know how you are powering the motor and arduino, we don't. You know how you are outputting digital logic to the H-Bridge, we don't.

A picture, a circuit diagram and a sketch is worth a thousand words and can save a thousand ill informed posts.

For us to give you anywhere near accurate and usefull help you need to help us too. We are at post #9 and still we know nothing about the motor voltage or how you have connected the H-Bridge to the arduino.

Tom.......Hope to help mate...... :)

rompelstilchen: ??? come on, you obviuosly did not even read my question (or maybe I asked it wrong)

:)