8051 pin voltage problem

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Hi,

to lower the current you should consider using another motor dirver.
Like LV85488MC, 1uA in OFF mode.

If interested, then look at manufacturers or distributors with selection guides for the driver ICs

Klaus
 

So I should connect pins 1 and 16 with 5V Vcc and pins 8 and 9 with 12V DC. Will this work with 8051 microcontroller? Please do tell me quickly. I will try it out and let you people know immediately.
 

Hi,

pins 8 and 9 with 12V DC
Click to expand...
Definitely no!

I can't find where anybody suggested to connect the enable pin to 12V.
Instead FvM clearly said:
enable inputs must be never connected to a voltage > 7V
Click to expand...

Klaus
 

I have 12V source and 5V being generated from it for the microcontroller. Please suggest me the connections. Its a request. I need to get this done ASAP. WIll you please tell me what voltage out of 12V and 5V should I provide to the pins mentioned as 1,16,8,9?
Thanking you in advance.

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Should I connect pins 1,9 and 16 to 5V source and pin 8 to 12V source and try it out??

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Okay so I did as per the suggestions and connected pins 1,9,16 to 5V and pin 8 to 12V but it is still behaving in the same way.
Please helppppp
 

Hi,

I really don't understand your problem. The definition is as clearly as can be:

12V is more than the 7V limit, so never use it for the signal inputs.
So only GND and 5V remain available.

To enable a driver use GND.
To disable (the unused) driver use 5V.

Your picture has correct enable connections, as long as you want to use only one driver.

Klaus
 

Here is what I have done now:
Connected pins 1,9,16 to 5V
Connected pin 8 to 12V.
Please tell me if it should work or not?
And should I do to make it work??
Please Mr. Klaus, help is utmost needed here.
 

Hi,

Your picture has correct enable connections, as long as you want to use only one driver.
Click to expand...

What else help do you need?
Regarding supply current: even when disabled both drivers, the IC will draw about 10mA of current. If this is too much you should consider another driver. See my post above.

Please describe exactly where you need help.

Klaus
 

Can you please tell me if the above mentioned connections should work??
Thats all I want to know right now.
 

Hi,

i think the answer was given multiple times:

Yes.
Technically. One driver is enabled. One driver is disabled. Everyting is within the specifications given in the datasheet.

BUT: Your description is so vague, so I can not be 100% sure if it fits to YOUR application. Only you know.

Klaus
 

Hi

See the attached video. It clearly shows that when EN pin is grounded then the two channels are disabled and when the EN pins are connected to 5V then the two channels are enabled. The logic state on INx pins decide whether your motor rotates clockwise or anti-clockwise. I guess that you have Proteus. You could have drawn the circuit and check the working.
 

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  • L293D Sim.rar
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Hi,

i just reviewed my posts and found a mistake.

In my post#25 i accidentally wrote the folowing:
To enable a driver use GND.
To disable (the unused) driver use 5V.
Click to expand...

But the opposite is true:
To disable the (unused) driver use GND.
To ensable a driver use 5V.

Excuse me if this was confusing you. In future please use the QUOTE to refer to a (doubtful) statement.

Again: Sorry.

Klaus
 

This is what I have done so far:
I connected both the enable pins to 5V dc and Vs to 12V dc but it is still not working.
I tried the circuit on proteus as welll with different ports i.e. PORT 0 and PORT 2 but it is not ready to work.
Here is the attachment of what happening. Take a look, the ports are not even enabled and nothing is happening.


- - - Updated - - -

I am sorry it got uploaded twice. Both images are same.
Please help ASAP.
 

Hi,

the ports are not even enabled and nothing is happening.
Click to expand...
If you speak of the PIC's ports, then what else do you expect?

Measure the voltages on pins 2, 3, 6, 7 and tell us.

Klaus
 

I tried it again on proteus and it worked and now I am gonna try and mend my hardware again and try. I will be back with an update after a while.
 

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