L293D pin 8 PROVIDING power?

Apologies if this is in the wrong section.

Just hooked up an L293D DC Motor Controller and ive noticed that pin 8 is PROVIDING power. I know this as i am using a 9V battery to a power supply module which has a green LED when it is on and recieving power.
When i remove the 9V battery, the light remained on which caused curiousity - after removing the cables one by one and re attatching, once i removed pin 8 (power input for the motor), the LED on my power supply module goes off.

Very confused to why and how its providing power.

My DC motor doesn't run by the way, im assuming it's this.

I've never heard of either a L2983D (in your title) or a L983D. And whatever you are actually talking about (I'm going to guess at L293D) I can't work out your wiring from that description.

Please post a schematic/wiring diagram showing ALL power connections and the correct names/links to all devices you have including the "power supply module".

Steve

slipstick:
I've never heard of either a L2983D (in your title) or a L983D. And whatever you are actually talking about (I'm going to guess at L293D) I can't work out your wiring from that description.

Please post a schematic/wiring diagram showing ALL power connections and the correct names/links to all devices you have including the "power supply module".

Steve

i meant to say L293d motor controller. It was quite late and i kept getting confused and told myself there was an "8" in there

Motor Controller:
Pin 1 -> Arduino Pin 5
Pin 2 -> Arduino Pin 4
Pin 3 -> Motor +
Pin 4 -> Power Supply Module - Rail
Pin 5 ->
Pin 6 -> Motor -
Pin 7 -> Arduino Pin 3
Pin 8 -> Power Supply Module + Rail

That's not a schematic, you have not said what "Power supply module" you're using or what the 9V battery is connected to. And just to check, are you using a bare L293D IC and not one of the many controller boards that contain an L293D?

And according to your connection list there are no power or ground connections to the Arduino and you don't have any 5V logic power to the L293D (pin 16). If that does anything at all I can't imagine how.

A picture of your setup clearly showing ALL components and wiring might help.

Steve

Pin-16 is the 5V Logic power
Pin-8 is the motor power.
You haven’t mentioned pin-16 in your post, which probably means your chip has
no logic power and therefore won’t work.
(slipstik beat me to it)
CONNECT +5V to pin 16.

raschemmel:
Pin-16 is the 5V Logic power
Pin-8 is the motor power.
You haven't mentioned pin-16 in your post, which probably means your chip has
no logic power and therefore won't work.
(slipstik beat me to it)
CONNECT +5V TO PIN-16 !

I followed this tutorial and he is using only 1 side of the motor controller. its connected to my motor the same way, i dont understand why his works and mine does not. Could it be because his power supply may be different than mine.. Ive connected a 9V battery,, i dont think he has.

You asked us why it doesn't work and we told you.
Are you going to try it or not ?

raschemmel:
You asked us why it doesn't work and we told you.
Are you going to try it or not ?

You told me to connect pin 16 to +5.. However i don't want to just copy something so it "works", I would like to have an understanding of whats happening.
My question is i have copied that tutorial step by step, and the motor is working for that guy but its not for me. He hasnt connected pin 16 to +5, he has 1-8 connected (apart from 5) and the way he explains the functionality of each pin makes total sense; yet it works for him and not for me.
and
How is the power module receiving power from pin 8 of the l293d chip?

Picture of 9v connected to power supply module to l293d to motor/ arduino

Also, i did connect Pin 16 to +5.. still nothing.

Read the datasheet:
"https://www.ti.com/lit/ds/symlink/l293.pdf"

I couldn't care less what some guy did on some YOUTUBE video because I read the datasheet and I have used that chip a dozen times and it always works when I connect +5V to pin 16. If you trust some stranger on the web more than you trust a datasheet then I have no sympathy. Maybe you should ask him then.

Also , you can't use a 9V PP3 smoke alarm battery
because their internal resistances not low enough to source enough current. This post is going nowhere
until you replace that battery with a 9V dc power supply or 12 V or six 1.5V AA batteries in series.

" and the way he explains the functionality of each pin makes total sense; yet it works for him and not for me"

Really ? That's interesting. WHAT EXACTLY did he say about VCC1 ? (nothing I'm guessing)

""How is the power module receiving power from pin 8 of the l293d chip?""

Without a schematic of your setup it's hard to be sure but it sounds like 'BACKFEEDING', when
power comes out of an input because it is backfeeding through the input protection diodes.
That's all I can say wirhout a schematic of the
circuit wiring.

raschemmel:
Read the datasheet:
"https://www.ti.com/lit/ds/symlink/l293.pdf"

I couldn't care less what some guy did on sone
YOUTUBE video because I read the datasheet
and I have used that chip a dozen times and it always works when I connect +5V to pin 16. If you trust some stranger on the web more than you trust a datasheet then I have no sympathy.
Maybe you should ask him then.

Also , you can't use a 9V PP3 smoke alarm battery
because their internal resistanceis not lowenough tosource enough current.This post is going nowhere
until you replace that battery with a 9V dc power
supply or 12 V or six 1.5V AA batteries in series.

" and the way he explains the functionality of each pin makes total sense; yet it works for him and not for me"

Really ? That's interesting. WHAT EXACTLY did he
say about VCC1 ? (nothing I'm guessing)

""How is the power module receiving power from pin 8 of the l293d chip?""

Without a schematic of your setup it's hard to be sure but it sounds like 'BACKFEEDING', when
power comes out of an input because it is backfeeding through the input protection diodes.
That's all I can say wirhout a schematic of the
circuit wiring.

I didn't come here for the hostility.
The schmatic apps are ridiculously confusing, for example, the l293d chip is always connected to 2 motors and not 1, like mine. And the schematic cant be edited either, it also doesnt go the arduino pins i have set it to and i cannot create one manually.
A disability stops me from making an accurate drawing using a pen, so instead of confusing you with a bad drawing, i said which pins were going where on the l293d, i guess i should apologise for my disability making your life harder.
I removed the power supply module (which i cannot find a part number for anywhere) and sent 8 AA batteries (12V) directly and the motor started spinning.
Pin 16 IS NOT being used.
So it looks like +5 doesn't always have to go there like i thought, and you infact, were wrong.
Thank you for your advice, it did not help at all, but it is clear that you know more about electronics than me.
The issue now is reducing the power sent to the motor as i smelt the motor burning, probably by using resistors etc, but looks like i'll figure this out alone again as i am new, still learning and NOT here for agression / hostility by a seasoned electrition/stranger.

What hostility ? I'm sorry but I don't know what you are referring to. Please provide examples.
There's no hostility.
If I say I don't care about a youtube video, that's not an expression of hostility. It is a simple statement of fact
that I don't care. There's nothing hostile about that.
I am not aware of anything in my post that expresses hostility. If there is , please show me.
There's a procedure that needs to be followed.
Can you explain this:

I removed the power supply module (which i cannot find a part number for anywhere) and sent 8 AA batteries (12V) directly and the motor started spinning.

Please post a pin wiring list.
When you say 'directly' , what do you mean ?

Pin 16 IS NOT being used

Pin 16 is VCC1, ( power for the logic circuits used to control the motor from a microprocessor. )
Did you connect pin16 when you connected the batteries and try running your sketch ?
Did follow my instructions exactly ?

The schmatic apps are ridiculously confusing,

There is no need for a schematic app.
If you can't draw a schematic with a pen and a blank sheet of printer paper, then just
post a point to point wiring list like you did before.

If you don't what I have told you , then look at this tutorial.
You will see clearly that pin-16 is used for input logic power.

If you won't answer questions and you won't take advice when it's given you seem to be going out of your way to make it difficult to help. So you're not seeing hostility but you are seeing a degree of frustration.

You control motor speed by using the PWM features of the L293D chip. Your tutorial shows that if you get to about 22 minutes in. Have you tried that part, changing mSpeed?

Steve

Post your code.
This is what you said in your OP:

Just hooked up an L293D DC Motor Controller and ive noticed that pin 8 is PROVIDING power. I know this as i am using a 9V battery to a power supply module which has a green LED when it is on and recieving power.
When i remove the 9V battery, the light remained on which caused curiousity - after removing the cables one by one and re attatching, once i removed pin 8 (power input for the motor), the LED on my power supply module goes off.

Very confused to why and how its providing power.

My DC motor doesn't run by the way, im assuming it's this.

After reading my post about the 9V battery not working , you posted this:

I removed the power supply module (which i cannot find a part number for anywhere) and sent 8 AA batteries (12V) directly and the motor started spinning.

Which resolve the first issue:
Motor not turning [check]
Then you posted this:

The issue now is reducing the power sent to the motor as i smelt the motor burning, probably by using resistors etc, but looks like i'll figure this out alone again as i am new, still learning and NOT here for agression / hostility by a seasoned electrition/stranger.

This issue is address in the Youtube video you posted, which , by the way, you apparently have not watched in it's
entirety, since he explains how to control the motor speed (as stated by Slipstick) and which is also explained by
the tutorial I linked.
So the question really is ,
why didn't you just tell us in you OP that you don't know how to use the L293D and would like to learn ?
Based on your statement above, you do not know how to control the motor power (that's the PWM Slipstick
mentioned). If you refuse to read the datasheet, did not watch the entire youtube video you linked, then it
is probably safe to assume you also don't know about motor En[able)
See page-1 : Pin-1: (1, 2EN)

raschemmel:
What hostility ? I'm sorry but I don't know what you are referring to. Please provide examples.
There's no hostility.
If I say I don't care about a youtube video, that's not an expression of hostility. It is a simple statement of fact
that I don't care. There's nothing hostile about that.
I am not aware of anything in my post that expresses hostility. If there is , please show me.
There's a procedure that needs to be followed.
Can you explain this:Please post a pin wiring list.
When you say 'directly' , what do you mean ?Pin 16 is VCC1, ( power for the logic circuits used to control the motor from a microprocessor. )
Did you connect pin16 when you connected the batteries and try running your sketch ?
Did follow my instructions exactly ?
There is no need for a schematic app.
If you can't draw a schematic with a pen and a blank sheet of printer paper, then just
post a point to point wiring list like you did before.

If you don't what I have told you , then look at this tutorial.
You will see clearly that pin-16 is used for input logic power.

Ill be more detailed to how its connected.
8 AA (12v) is connected to the + and - rails on a breadboard
L293d motor controller board is on the breadboard
Pin 1 -> Arduino Pin 5 (control speed)
Pin 2 -> Arduino Pin 4 (Motor Direction)
Pin 3 -> Motor positive cable
Pin 4 -> Ground rail on BB
Pin 5 ->
Pin 6 -> Motor negative cable
Pin 7 -> Arduino Pin 3 (Motor Direction)
Pin 8 -> Power input from + rail on BB
The BB Negative- Rail is connected to the GND on the arduino
The other side of the l293d module is not connected to anything. So pins 9-16 have no connection.
Arduino is powered via USB.
I tried your way and i simply added a wire from pin 16 to +5 and nothing happened. After removing the power supply module i tried it again with 12v and nothing happened again. The motor started spinning upon removal of the jump cable to pin 16.
You may be right that Pin 16 is logic power, but its working without me connecting power to it. Very curious to why this is happening

raschemmel:
Post your code.

int speedPin=5;
int dir1=4;
int dir2=3;
int mSpeed=255;

void setup()
{
pinMode(speedPin,OUTPUT);
pinMode(dir1,OUTPUT);
pinMode(dir2,OUTPUT);
Serial.begin(9600);
}

void loop()
{
digitalWrite(dir1,HIGH);
digitalWrite(dir2,LOW);
analogWrite(speedPin,mSpeed);
}

Ill be more detailed to how its connected.
8 AA (12v) is connected to the + and - rails on a breadboard
L293d motor controller board is on the breadboard
Pin 1 -> Arduino Pin 5 (control speed)
Pin 2 -> Arduino Pin 4 (Motor Direction)
Pin 3 -> Motor positive cable
Pin 4 -> Ground rail on BB
Pin 5 ->
Pin 6 -> Motor negative cable
Pin 7 -> Arduino Pin 3 (Motor Direction)
Pin 8 -> Power input from + rail on BB
The BB Negative- Rail is connected to the GND on the arduino
The other side of the l293d module is not connected to anything. So pins 9-16 have no connection.
Arduino is powered via USB.
I tried your way and i simply added a wire from pin 16 to +5 and nothing happened. After removing the power supply module i tried it again with 12v and nothing happened again. The motor started spinning upon removal of the jump cable to pin 16.
You may be right that Pin 16 is logic power, but its working without me connecting power to it. Very curious to why this is happening

Ok, I guess we have to try a different approach. Since you won't tell us that you have no logic experience, we
have to try it a different way.
'Logic' is the language of the microprocessor.
If you connect 5V to the Logic Power input, then the chip immediately becomes ready to accept logic commands.
The motor is not going to automatically start moving because you connected the logic power.
The chip is now saying to you "Speak to me in LOGIC !"
"command Arduino pin 5 HIGH to ENABLE motor outputs 1,2 (pin-1 : 1,2 EN)

const int IN1 = 6, IN2 = 5, IN3 = 11, IN4 = 10;
const int enable12 = 3 , enable34 = 9;
void setup()
{
  pinMode(IN1, OUTPUT);
  pinMode(IN2, OUTPUT);
  pinMode(IN3, OUTPUT);
  pinMode(IN4, OUTPUT);
  pinMode(enable12, OUTPUT);
  pinMode(enable34, OUTPUT);
  digitalWrite(enable12, HIGH);
  digitalWrite(enable34, HIGH);
}

void loop()
{
  clockwise();
  delay(5000);
  anticlockwise();
  delay(5000);
  brake();
  delay(5000);
}
// Input state to rotate 2 motors CW
void clockwise()
{
  digitalWrite(IN1, HIGH);
  digitalWrite(IN2, LOW);
  digitalWrite(IN3, HIGH);
  digitalWrite(IN4, LOW);
}
// Input state to rotate 2 motors CCW
void anticlockwise()
{
  digitalWrite(IN1, LOW);
  digitalWrite(IN2, HIGH);
  digitalWrite(IN3, LOW);
  digitalWrite(IN4, HIGH);
}
//Motor Brake
void brake()
{
  digitalWrite(IN1, LOW);
  digitalWrite(IN2, LOW);
  digitalWrite(IN3, LOW);
  digitalWrite(IN4, LOW);
}

Note that since In1 is High, In2 must be low for the motor to turn
This example is using simple digitalWrite .
Do you know what PWM is ?

raschemmel:
Post your code.
This is what you said in your OP:After reading my post about the 9V battery not working , you posted this:Which resolve the first issue:
Motor not turning [check]
Then you posted this:This issue is address in the Youtube video you posted, which , by the way, you apparently have not watched in it's
entirety, since he explains how to control the motor speed (as stated by Slipstick) and which is also explained by
the tutorial I linked.
So the question really is ,
why didn't you just tell us in you OP that you don't know how to use the L293D and would like to learn ?
Based on your statement above, you do not know how to control the motor power (that's the PWM Slipstick
mentioned). If you refuse to read the datasheet, did not watch the entire youtube video you linked, then it
is probably safe to assume you also don't know about motor En[able)
See page-1 : Pin-1: (1, 2EN)

I did watch the video all the way. Ive been following all of his lessons to the bone for a few months, this means watching his videos repeatedly and then doing what he says after the 2nd or 3rd watch while still watching what he does.
The motor power is running perfectly fine now that i removed the power suppply module (and changed power source) so my issue had NOTHING with the 3 things you said(controlling power, reading the data sheet or watching the entire video)..
Also- if I’m using a tutorial for such a basic thing, running a £2 motor with a very simple circuit, i think its more than obvious that I’m a beginner and learning. I never refused to the read the data sheet, excuse me?

raschemmel:
Do you know what PWM is ?

I do. So i understand the logic now BUT do you think i require logic when all i need is for the motor to run and stop on a button press? Or do you think I’ll be okay with what I’m doing now for just a simple motor spin?

Arduino pin 5 is connected to L293D-1, which has nothing to do with speed. If you read the datasheet you will see

L293D-1 is the ENable pin for outputs 1 & 2. The speed is controlled by the PWM duty cycle on L293D pins 2 & 7. (the ones you labeled Motor Direction)

The L293D is a dumb controller. It has NO DIR control. Pins 2 & 7 are the H-Bridge inputs, which control the

motor direction. To save time , would you please give a brief background of your electronics and arduino and H-Bridge experience as it applies to your post.

Look at the PINOUT from the DATASHEET.

Do you see ANY mention of SPEED, or DIR ?

The ENABLE pin-1 should be kept High as long as you want the motor to run and brought low to stop the motor.

That's what an Enable pin does. All motor controllers have them . They have one function. Enable/Disable the motor, nothing else. They have nothing to do with speed or direction.

My bad. It's been so long since I used the L293D I forgot the pin functions.
You were right , the ENable pins 1, & 9 are the PWM inputs,
and the IN1,IN2, IN3 & IN4 are used to set the direction (one H , the other L)

slipstick:
You control motor speed by using the PWM features of the L293D chip. Your tutorial shows that if you get to about 22 minutes in. Have you tried that part, changing mSpeed?

Momentarily forgot about this but yes, i can do that. Also, i was thinking the 12V may be too much for the 1-6v motor, so while keeping the same max speed, you think it’ll be beneficial to add a resistor to the circuit?