Nodemcu ESP 12F getting hot when using with L293D

Hi,

I have a requirement to spin a dc motor using Nodemcu [or wemos D1 mini] and using L293D driver [ IC only, not board]

My connections are as attached.

Though the project works, It is getting hot, even when it is idle.

Ideally, I would like to use max 1 x 18650 , but as the motor is not running fast, I am using 4 x 1.2 AA

Question: why is my Nodemcu becoming so hot. Is there anything wrong in the connections?

Give us a wiring showing how power is distributed. I can't read that info from Your picture.

Eagle doesnt allow color lines, so used different types.

I did mention about, power distribution - 4 x 1.2 AA = 4.8 volts 2100mAh, fed to vin of nodemcu, pin8 and pin16 of l293D

If your drawing is correct, does it match your wiring. You made a bad choice for a driver. Using round numbers the voltage drop across each output will be 1.5V, that equals your motor supply voltage - 3 volts. 4.8V - 3V = 1.8 volts for the motor. From this should realize you do not have enough voltage for proper operation. If my memory is correct you have a regulator on the Nodemcu, that takes about 1.2 volts away from the 4.8 volts leaving you 0,3 volts max headroom left for the Nodemcu. If you check the impedance of the batteries and age I believe you will be under voltage on everything. This is my best guess from what you show.

gilshultz:
If your drawing is correct, does it match your wiring. You made a bad choice for a driver. Using round numbers the voltage drop across each output will be 1.5V, that equals your motor supply voltage - 3 volts. 4.8V - 3V = 1.8 volts for the motor. From this should realize you do not have enough voltage for proper operation. If my memory is correct you have a regulator on the Nodemcu, that takes about 1.2 volts away from the 4.8 volts leaving you 0,3 volts max headroom left for the Nodemcu. If you check the impedance of the batteries and age I believe you will be under voltage on everything. This is my best guess from what you show.

I have connected similar to https://www.instructables.com/id/ESP8266-Wifi-Controlled-Robot/

I have only 1 motor, so using only 1 side of L293D.

How can I fix the voltage drop?

Get a halfway modern H-bridge. The L293D belongs in the museum.

The TB6621FNG is one example of a dual H-bridge, or the DRVxxxx series of H-bridges.

wvmarle:
Get a halfway modern H-bridge. The L293D belongs in the museum.

The TB6621FNG is one example of a dual H-bridge, or the DRVxxxx series of H-bridges.

Like - DRV8825 ?

I use it for my stepped motor [ nema 17 and using 12V supply]

please can you help me understand your suggestion - is it going to save power, and protect nodemcu from bricking? how can I connect drv8825?

krisferrari:
How can I fix the voltage drop?

Run the MCU and H driver from separate power supplies.

aarg:
Run the MCU and H driver from separate power supplies.

Thanks.
Is 1x 18650 for nodemcu and another 1 x 18650 for l293d ok? I have space constraint.
I do have L298N, if that is better

  • or I can replace nodemcu with a wemos d1 mini

krisferrari:
Is 1x 18650 for nodemcu and another 1 x 18650 for l293d ok? I have space constraint.

Read the data sheet - it clearly lists the voltage drop over the darlington stages. You'll see you have about 0.5V left for the motor.

I do have L298N, if that is better

No difference. Also an old BJT based IC.

In contrast: the MOSFET based TB6621FNG doesn't have the voltage drop (just a small on resistance - again see datasheet for the details), and as a result it comes in a much smaller package and doesn't require that bulky heat sink.

The WeMOS D1 Mini much smaller, and is a functionally equivalent to the NodeMCU for most applications; one of the key differences is that the NodeMCU has GPIO6-11 of the ESP8266 broken out.

wvmarle:
Read the data sheet - it clearly lists the voltage drop over the darlington stages. You'll see you have about 0.5V left for the motor.

No difference. Also an old BJT based IC.

In contrast: the MOSFET based TB6621FNG doesn't have the voltage drop (just a small on resistance - again see datasheet for the details), and as a result it comes in a much smaller package and doesn't require that bulky heat sink.

The WeMOS D1 Mini much smaller, and is a functionally equivalent to the NodeMCU for most applications; one of the key differences is that the NodeMCU has GPIO6-11 of the ESP8266 broken out.

Thanks.

I have used WemosD1 and bricked :slight_smile: , supplied a lot of volts to 3v3 pin.[ should have use 5v]

I am left with only 1 wemos d1 mini. It has enpugh pins for my project.

gilshultz:
If your drawing is correct, does it match your wiring. You made a bad choice for a driver. Using round numbers the voltage drop across each output will be 1.5V, that equals your motor supply voltage - 3 volts. 4.8V - 3V = 1.8 volts for the motor. From this should realize you do not have enough voltage for proper operation. If my memory is correct you have a regulator on the Nodemcu, that takes about 1.2 volts away from the 4.8 volts leaving you 0,3 volts max headroom left for the Nodemcu. If you check the impedance of the batteries and age I believe you will be under voltage on everything. This is my best guess from what you show.

If using wemos saves 1.2v , then I will Wemos. please advice

wvmarle:
Get a halfway modern H-bridge. The L293D belongs in the museum.

The TB6621FNG is one example of a dual H-bridge, or the DRVxxxx series of H-bridges.

Can DRV8825 be used?
Please can you tell me how to use DERV8825 with a DC motor

Hi,
I want to spin 1 DC motor. How much voltage should I provide to the setup as in the picture

Is 3.7V enough?

20200330_184931.jpg

20200330_184931.jpg

For some unknown motor? Who could guess? By the way, connecting a motor directly to a processor pin is a very bad idea. What is the "hat" board? It's not clear where you are planning to apply 3.7V...

If you give us all your information up front, we won't have to get into 30 posts to figure out what you have.

Its a Wemos motor driver

It is "a Wemos driver". What if there are several differet drivers? Read the data sheet of the driver, the motor and maybe, for the Wemos. Designing electronics without read specifications will create quit some toast.

wvmarle:
In contrast: the MOSFET based TB6621FNG doesn't have the voltage drop (just a small on resistance - again see datasheet for the details), and as a result it comes in a much smaller package and doesn't require that bulky heat sink.

The WeMOS D1 Mini much smaller, and is a functionally equivalent to the NodeMCU for most applications; one of the key differences is that the NodeMCU has GPIO6-11 of the ESP8266 broken out.

I changed the setup, but I'm not sure how much voltage, I have to supply.

The article says - https://www.instructables.com/id/Low-Cost-WiFi-Controlled-Motor-Using-Lolin-D1-Mini/
says 8V - 15V

But I shifted from L293D to TB747A3, so that I can spin using less batteries. But if I have to supply 8v, then it doesnt fit my goal.

Dont understand why it is so power hungry? just to spin a single DC motor

duplicate post
https://forum.arduino.cc/index.php?topic=674125.0

@krisferrari

TOPIC MERGED.

Could you take a few moments to Learn How To Use The Forum.
Other general help and troubleshooting advice can be found here.
It will help you get the best out of the forum.

krisferrari:
I changed the setup, but I'm not sure how much voltage, I have to supply.

The article says - https://www.instructables.com/id/Low-Cost-WiFi-Controlled-Motor-Using-Lolin-D1-Mini/
says 8V - 15V

Don't trust instructables - check the data sheet of the motor driver on voltage limits.

Dont understand why it is so power hungry? just to spin a single DC motor

It's a motor... they need a lot of power.

How much? Check the specifications of your motor. Maybe it's happy with 3.7V. Maybe it needs 200V. Maybe something in between. Also make sure your power supply is able to supply sufficient current. How much? Look it up. The motor's data sheet will clearly list this.