Continue to Site

Welcome to our site!

Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

  • Welcome to our site! Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

dc motor circuit with L293D

Status
Not open for further replies.
What you posted looks fine. There must be something awry with the inputs or connections between what you posted and the outside world, or bad components. Is the ground connection in the schematic connected to the ground of the circuit driving the inputs? Are the inputs the proper voltage levels (Low input is below 1.5V) and states required to run the motor? Can the +12V supply provide the required power and can the 293D provide the drive the motor requires? Is the ground of each supply connected to ground in the schematic circuit? Is anything getting hot, esp the 293D? Tie the unused inputs to +5V for good measure.

Divide and conquer. Remove schematic circuit from everything else. Double check all connections. Connect power supplies. Connect the enable input to +5V. Manually connect one input to +5V and the other to ground. Motor should run in one direction. Manually connect the other input to +5V and the other to ground. Motor should run in other direction. If not check power supply voltages. Check motor voltage.
 
Last edited:
We do not know what your input signals are doing.
We don't know how much current the motor needs.
 
Thank you all its working now ! i have a question now. can i use 8051 mircocontroller to control the rotation of the dc motor? or can i use hardware instead of programming?
 
!
i have a question now. can i use 8051 mircocontroller to control the rotation of the dc motor? or can i use hardware instead of programming?

It depends on the flavor of 8051 (need exact part number) you are using and what voltage you are supplying to it. That information is needed to determine the answer for certain. Some microcontrollers can source very little current in the high output state because they have weak internal pull-up resistors to provide for low drive requirements for when they are used as inputs. External pull-up resistors may be necessary. The 293 can require as much as 100 uA (worst case) in the high state. Of course, you can always provide the required inputs using other hardware without programming.
 
oh its 8051F330. and without using programming any idea where can i get the circuits for the hardware or what should i research to build a circuit for the hardware?
 
I see no data for a 8051F330, so I assume you mean C8051F330. It is a 3.3V part. It will barely drive the 293 (operating at 5V supply) to a proper high (2.3V) if you configure the corresponding I/O port pins for "Push-Pull" output mode. The I/O ports of the C8051F330 are 5 volt tolerant, so I would add an external pull-up resistor (4.7K) from each 293 input to +5V to ensure a solid high level. Providing low logic level is not a problem.
 
Last edited:
Connect the motor as shown in the attachment.

VCC1 is the logic supply voltage (same as microcontroller)
VCC2 is motor supply voltage .

Boncuk
 
Last edited:
my teacher wants me to do a hardware instead of programming to turn it clockwise and anti clockwise by using a transmitter i already have built so any idea i can send signal to turn different direction?
 
You already know that you need two TTL or CMOS level outputs to control the motor, and that part operates fine. So, whatever receiver (not a clue here what that is) is used with your transmitter has to supply those inputs. Give that a shot as you did with the motor control schematic. If you need help, post your schematic for review.
 
my teachers mention to built a 2-4 decoder for the input of my dc motor the controller the direction of the motor. you have any idea ?
 
No, I'm afraid I don't. The motor driver needs only two inputs. A 2-4 decoder takes two inputs and makes four outputs. ?
 
should i use an ADC for the LM358N IR sensor to interface with AT89C51?

Firstly you should make your own thread instead of hijacking existing ones and secondly the LM358N is no IR sensor. It's an operational amplifier.

Boncuk
 
my teachers mention to built a 2-4 decoder for the input of my dc motor the controller the direction of the motor. you have any idea ?

Using a 2-4 decoder (e.g. SN74HC139) you will require switches for the desired outputs to control the L293. If you keep EN high at all times you'll need two DPST switches or two SPST switches to control the motor.

When using SPST switches you must use pull down resistors at "A" and "B".

Boncuk
 
woahh thanks man ! but can i have a more detailed one? is it possible for you to draw this up using eagles? i cant really tell which are the component.. and my teacher says its wrong because i need logic gates instead of switches as i have a transmitter with a keypad. someone help pls ! enlighten me as my teacher is too impatient to explain anything.. and he is rushing me to submit a circuit.. any information on how to use logic gates to turn in Counter clockwise and clockwise would be big help !
 
Last edited:
i actually need the 74VHC139 to send the signal.. but i figuring how can i get the power circuit to give my 2 inputs in my motor either 1 to be high and 1 to be low
 
Status
Not open for further replies.

Latest threads

New Articles From Microcontroller Tips

Back
Top