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Topic: Arduino shutting down when 4 motors are connected (Read 1 time) previous topic - next topic

SimpleThings

Hello guys I am trying to run 4 DC motors https://www.ebay.com/p/4wd-Robot-Smart-Car-Chassis-Kits-Car-With-Speed-Encoder-for-Arduino-M26/2136379574

These motors need 3V-6V to operate. So I connected these 4 motors to adafruits motor shield V1 that used 2xL293D and one shift register. For remote control I am using HC05 bluetooth module. When I try to run all four motors my arduino shuts down after few seconds. When only 2/3 motors are connected to power, arduino works perfectly and so do motors, this thing only happens when only all four motors are connected. I tried to change adafruits motor shield to another, to make sure that problem isn't really with shield. I haven't connected any resistors with bluetooth module, instead I connected it directly.

After that I thought that maybe output current isn't enough, so I used seperate Vcc for both arduino and shield, but same thing continued to happen.

Then by my logic I concluded that there must be a problem with HC05, so I decided not to use bluetooth module this time, and connected arduino directly to Serial port, and it worked, without any problems.

Has anyone experienced similar problem with their bluetooth module, and if so how to tackle this problem?

Power_Broker

I don't think it's the bluetooth module, I think it's a power issue. To be sure, can you post a schematic of how everything is powered?
"The desire that guides me in all I do is the desire to harness the forces of nature to the service of mankind."
   - Nikola Tesla

SimpleThings


Wawa

The diagram doesn't tell me where that 6volt is coming from.
And how the Mega is powered.
That V1 shield is old tech, and 6volt will give about 3.5volt max to the motors.

The BT module is a 3,3volt device.
While it should be powered from 5volt, the RX pin should have a 1:2 voltage divider to drop 5volt logic to 3.3volt.
Leo..

SimpleThings

Vcc is arduino 5V output pin that powers both HC05 and shield.
Mega is powered through RS232 cable.


Power_Broker

Vcc is arduino 5V output pin that powers both HC05 and shield.
Mega is powered through RS232 cable.
If someone asks for a schematic, POST A SCHEMATIC.


I don't think it's the bluetooth module, I think it's a power issue. To be sure, can you post a schematic of how everything is powered?
"The desire that guides me in all I do is the desire to harness the forces of nature to the service of mankind."
   - Nikola Tesla

Wawa

Vcc is arduino 5V output pin that powers both HC05 and shield.

Mega is powered through RS232 cable.
The shield needs two power sources. Logic power (from the Mega's 5volt pin) and motor power.
Were does motor power come from.

RS232 ? diagram please.
Leo..

SimpleThings


MarkT

If you are trying to power the motor shield from the Arduino's 5V logic rail, you need to
rethink your power supply arrangement.

Motors take lots of current (amps) and put spikes and noise on their supply (incompatible
with running logic chips off that supply).  In the worst case running motors from the 5V rail
could damage Arduino and or the computer providing the USB 5V.  I wouldn't take that risk.
Keep power/motors separate from logic/signal.

So a 2A or more supply for the motors separate from the Arduino 5V would be more reasonable.
[ I will NOT respond to personal messages, I WILL delete them, use the forum please ]

SimpleThings

#9
Jun 27, 2017, 02:23 pm Last Edit: Jun 27, 2017, 02:28 pm by SimpleThings
I have tried to use seperate power supply, this power supply configuration is just only for test purposes until I make sure that it is completly working.

I know that motors require a lot of current, therefore I lifted car chasis upwards, removing it from ground, to make sure that car is actually stacionary in order to minimum torque on the motors and therefore minimize motor current. I have soldered capacitors to each motor power terminals, also there are extra capacitors near DC motor drivers to protect the microcontroller from voltage spikes.

MarkT

Quote
I have tried to use seperate power supply, this power supply configuration is just only for test purposes until I make sure that it is completly working.
So you are happy to overload/break something in testing?  Doesn't sound sensible.

When you tried to use a separate supply, was it powerful enough, was it connected correctly, what happened?
[ I will NOT respond to personal messages, I WILL delete them, use the forum please ]

terryking228

Hi,
You need a separate power supply for the motors. Is that clear, now?

Look at the diagram of that shield. It has a jumper so you can remove it to use external power.

See THIS PAGE which is a nice tutorial and all the information you need. Written by the Lady who DESIGNED this shield.
Regards, Terry King terry@yourduino.com  - Check great prices, devices and Arduino-related boards at http://YourDuino.com
HOW-TO: http://ArduinoInfo.Info

SimpleThings

So you are happy to overload/break something in testing?  Doesn't sound sensible.

When you tried to use a separate supply, was it powerful enough, was it connected correctly, what happened?
I am not sure how am I gonna break it with 5VDC USB power supply?

It was 9 VDC with 1.5 A of output current. It was connected correctly, motors started to spin, but after few seconds microcontroller shut down.

Hi,
You need a separate power supply for the motors. Is that clear, now?

Look at the diagram of that shield. It has a jumper so you can remove it to use external power.

See THIS PAGE which is a nice tutorial and all the information you need. Written by the Lady who DESIGNED this shield.
I am aware of that there is a power jumper, I have tested it with separate power supply with removed jumper. However chip heat up real quick. I will try to get another power supply tomorrow and test it and give you a feedback.

Wawa

Is this better than the previous?
No.
You tell us in post#0 that you're using an (obsolete) Adafruit V1 shield.
And then you post a picture of a sparkfun board.
No proper advice can be given if you don't tell us exactly what you have.
A real picture could also help.
Leo..

SimpleThings

No.
You tell us in post#0 that you're using an (obsolete) Adafruit V1 shield.
And then you post a picture of a sparkfun board.
No proper advice can be given if you don't tell us exactly what you have.
A real picture could also help.
Leo..
Yes I am using Adafruit V1 shield: http://1.bp.blogspot.com/-8hRQoCtnSwQ/VRmIJ-C0l1I/AAAAAAAAAhg/M4ckOs-2Su4/s1600/L293DMotorSield.jpg

, there is not such a shield in fritzing program, so I just put that one. I mean, the shield has to be only attached to the atmega2560, I simply do not understand what do you want me to do? At proteus schematics, I showed how atmega2560 is connected to the shift register and motor drivers.
I will ask someone else to do a picture for me since my smartphone is currently broken.

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