Skip to main content
Robotics

Return to Question

Notice removed Draw attention by Hamzah Malik
Bounty Ended with Chuck's answer chosen by Hamzah Malik
added 427 characters in body
Source Link
Hamzah Malik
Hamzah Malik
  • 123
  • 1
  • 10

Below are some pictures. You can use the colour of the cables to link them between pictures

enter image description here enter image description here enter image description here enter image description here

Below are some pictures. You can use the colour of the cables to link them between pictures

enter image description here enter image description here enter image description here enter image description here

Added image of diff
Source Link
edit approved Feb 2, 2016 at 19:55
Greenonline
edit approved Feb 2, 2016 at 19:55
Greenonline
  • 1.7k
  • 6
  • 21
  • 32

My small robot has two motors controlled by an L293D and that is controlled via a Raspberry Pi. They will both go forwards but only one will go backwards.

I've tried different motors and tried different sockets in the breadboard, no luck. Either the L293D's chip is broken (but then it wouldn't go forwards) or I've wired it wrong.

I followed the tutorial, Controlling DC Motors Using Python With a Raspberry Pi, exactly.

Here is a run down of what works. Let the 2 motors be A and B When:

When I use a python script (see end of post) both motors go "forwards". When I change the values in the Python script, so the pin set to HIGH and the pin set to LOW are swapped, motor A will go "backwards", this is expected. However, motor B will not move at all. If

If I then swap both motors' wiring then the original python script will make both go backwards but swapping the pins in the code will make motor A go forwards but motor B won't move.

So basically, motor A will go forwards or backwards depending on the python code but motor B can only be changed by physically changing the wires.

This is forwards.pyforwards.py

import RPi.GPIO as GPIO
from time import sleep

GPIO.setmode(GPIO.BOARD)

Motor2A = 23
Motor2B = 21
Motor2E = 19

Motor1A = 18
Motor1B = 16
Motor1E = 22

GPIO.setup(Motor1A, GPIO.OUT)
GPIO.setup(Motor1B, GPIO.OUT)
GPIO.setup(Motor1E, GPIO.OUT)

GPIO.setup(Motor2A, GPIO.OUT)
GPIO.setup(Motor2B, GPIO.OUT)
GPIO.setup(Motor2E, GPIO.OUT)

print("ON")
GPIO.output(Motor1A, GPIO.HIGH)
GPIO.output(Motor1B, GPIO.LOW)
GPIO.output(Motor1E, GPIO.HIGH)

GPIO.output(Motor2A, GPIO.HIGH)
GPIO.output(Motor2B, GPIO.LOW)
GPIO.output(Motor2E, GPIO.HIGH)

And this is backwards.pybackwards.py

import RPi.GPIO as GPIO
from time import sleep

GPIO.setmode(GPIO.BOARD)

Motor2A = 21
Motor2B = 23
Motor2E = 19

Motor1A = 16
Motor1B = 18
Motor1E = 22

GPIO.setup(Motor1A, GPIO.OUT)
GPIO.setup(Motor1B, GPIO.OUT)
GPIO.setup(Motor1E, GPIO.OUT)

GPIO.setup(Motor2A, GPIO.OUT)
GPIO.setup(Motor2B, GPIO.OUT)
GPIO.setup(Motor2E, GPIO.OUT)

print("ON")
GPIO.output(Motor1A, GPIO.HIGH)
GPIO.output(Motor1B, GPIO.LOW)
GPIO.output(Motor1E, GPIO.HIGH)

GPIO.output(Motor2A, GPIO.HIGH)
GPIO.output(Motor2B, GPIO.LOW)
GPIO.output(Motor2E, GPIO.HIGH)

If you see this diff https://www.diffchecker.com/skmx6084, you can see the difference:

Screenshot of code diff

My small robot has two motors controlled by an L293D and that is controlled via a Raspberry Pi. They will both go forwards but only one will go backwards.

I've tried different motors and tried different sockets in the breadboard, no luck. Either the L293D's chip is broken (but then it wouldn't go forwards) or I've wired it wrong.

I followed the tutorial, Controlling DC Motors Using Python With a Raspberry Pi, exactly.

Here is a run down of what works. Let the 2 motors be A and B When I use a python script (see end of post) both motors go "forwards". When I change the values in the Python script, so the pin set to HIGH and the pin set to LOW are swapped, motor A will go "backwards", this is expected. However, motor B will not move at all. If I then swap both motors' wiring then the original python script will make both go backwards but swapping the pins in the code will make motor A go forwards but motor B won't move

So basically, motor A will go forwards or backwards depending on the python code but motor B can only be changed by physically changing the wires

This is forwards.py

import RPi.GPIO as GPIO
from time import sleep

GPIO.setmode(GPIO.BOARD)

Motor2A = 23
Motor2B = 21
Motor2E = 19

Motor1A = 18
Motor1B = 16
Motor1E = 22

GPIO.setup(Motor1A, GPIO.OUT)
GPIO.setup(Motor1B, GPIO.OUT)
GPIO.setup(Motor1E, GPIO.OUT)

GPIO.setup(Motor2A, GPIO.OUT)
GPIO.setup(Motor2B, GPIO.OUT)
GPIO.setup(Motor2E, GPIO.OUT)

print("ON")
GPIO.output(Motor1A, GPIO.HIGH)
GPIO.output(Motor1B, GPIO.LOW)
GPIO.output(Motor1E, GPIO.HIGH)

GPIO.output(Motor2A, GPIO.HIGH)
GPIO.output(Motor2B, GPIO.LOW)
GPIO.output(Motor2E, GPIO.HIGH)

And this is backwards.py

import RPi.GPIO as GPIO
from time import sleep

GPIO.setmode(GPIO.BOARD)

Motor2A = 21
Motor2B = 23
Motor2E = 19

Motor1A = 16
Motor1B = 18
Motor1E = 22

GPIO.setup(Motor1A, GPIO.OUT)
GPIO.setup(Motor1B, GPIO.OUT)
GPIO.setup(Motor1E, GPIO.OUT)

GPIO.setup(Motor2A, GPIO.OUT)
GPIO.setup(Motor2B, GPIO.OUT)
GPIO.setup(Motor2E, GPIO.OUT)

print("ON")
GPIO.output(Motor1A, GPIO.HIGH)
GPIO.output(Motor1B, GPIO.LOW)
GPIO.output(Motor1E, GPIO.HIGH)

GPIO.output(Motor2A, GPIO.HIGH)
GPIO.output(Motor2B, GPIO.LOW)
GPIO.output(Motor2E, GPIO.HIGH)

If you see this diff https://www.diffchecker.com/skmx6084 you can see the difference

My small robot has two motors controlled by an L293D and that is controlled via a Raspberry Pi. They will both go forwards but only one will go backwards.

I've tried different motors and tried different sockets in the breadboard, no luck. Either the L293D's chip is broken (but then it wouldn't go forwards) or I've wired it wrong.

I followed the tutorial, Controlling DC Motors Using Python With a Raspberry Pi, exactly.

Here is a run down of what works. Let the 2 motors be A and B:

When I use a python script (see end of post) both motors go "forwards". When I change the values in the Python script, so the pin set to HIGH and the pin set to LOW are swapped, motor A will go "backwards", this is expected. However, motor B will not move at all.

If I then swap both motors' wiring then the original python script will make both go backwards but swapping the pins in the code will make motor A go forwards but motor B won't move.

So basically, motor A will go forwards or backwards depending on the python code but motor B can only be changed by physically changing the wires.

This is forwards.py

import RPi.GPIO as GPIO
from time import sleep

GPIO.setmode(GPIO.BOARD)

Motor2A = 23
Motor2B = 21
Motor2E = 19

Motor1A = 18
Motor1B = 16
Motor1E = 22

GPIO.setup(Motor1A, GPIO.OUT)
GPIO.setup(Motor1B, GPIO.OUT)
GPIO.setup(Motor1E, GPIO.OUT)

GPIO.setup(Motor2A, GPIO.OUT)
GPIO.setup(Motor2B, GPIO.OUT)
GPIO.setup(Motor2E, GPIO.OUT)

print("ON")
GPIO.output(Motor1A, GPIO.HIGH)
GPIO.output(Motor1B, GPIO.LOW)
GPIO.output(Motor1E, GPIO.HIGH)

GPIO.output(Motor2A, GPIO.HIGH)
GPIO.output(Motor2B, GPIO.LOW)
GPIO.output(Motor2E, GPIO.HIGH)

And this is backwards.py

import RPi.GPIO as GPIO
from time import sleep

GPIO.setmode(GPIO.BOARD)

Motor2A = 21
Motor2B = 23
Motor2E = 19

Motor1A = 16
Motor1B = 18
Motor1E = 22

GPIO.setup(Motor1A, GPIO.OUT)
GPIO.setup(Motor1B, GPIO.OUT)
GPIO.setup(Motor1E, GPIO.OUT)

GPIO.setup(Motor2A, GPIO.OUT)
GPIO.setup(Motor2B, GPIO.OUT)
GPIO.setup(Motor2E, GPIO.OUT)

print("ON")
GPIO.output(Motor1A, GPIO.HIGH)
GPIO.output(Motor1B, GPIO.LOW)
GPIO.output(Motor1E, GPIO.HIGH)

GPIO.output(Motor2A, GPIO.HIGH)
GPIO.output(Motor2B, GPIO.LOW)
GPIO.output(Motor2E, GPIO.HIGH)

If you see this diff https://www.diffchecker.com/skmx6084, you can see the difference:

Screenshot of code diff

Notice added Draw attention by Hamzah Malik
Bounty Started worth 50 reputation by Hamzah Malik
added 2174 characters in body
Source Link
Hamzah Malik
Hamzah Malik
  • 123
  • 1
  • 10

My small robot has two motors controlled by an L293D and that is controlled via a Raspberry Pi. They will both go forwards but only one will go backwards.

I've tried different motors and tried different sockets in the breadboard, no luck. Either the L293D's chip is broken (but then it wouldn't go forwards) or I've wired it wrong.

I followed the tutorial, Controlling DC Motors Using Python With a Raspberry Pi, exactly.

Here is a run down of what works. Let the 2 motors be A and B When I use a python script (see end of post) both motors go "forwards". When I change the values in the Python script, so the pin set to HIGH and the pin set to LOW are swapped, motor A will go "backwards", this is expected. However, motor B will not move at all. If I then swap both motors' wiring then the original python script will make both go backwards but swapping the pins in the code will make motor A go forwards but motor B won't move

So basically, motor A will go forwards or backwards depending on the python code but motor B can only be changed by physically changing the wires

This is forwards.py

import RPi.GPIO as GPIO
from time import sleep

GPIO.setmode(GPIO.BOARD)

Motor2A = 23
Motor2B = 21
Motor2E = 19

Motor1A = 18
Motor1B = 16
Motor1E = 22

GPIO.setup(Motor1A, GPIO.OUT)
GPIO.setup(Motor1B, GPIO.OUT)
GPIO.setup(Motor1E, GPIO.OUT)

GPIO.setup(Motor2A, GPIO.OUT)
GPIO.setup(Motor2B, GPIO.OUT)
GPIO.setup(Motor2E, GPIO.OUT)

print("ON")
GPIO.output(Motor1A, GPIO.HIGH)
GPIO.output(Motor1B, GPIO.LOW)
GPIO.output(Motor1E, GPIO.HIGH)

GPIO.output(Motor2A, GPIO.HIGH)
GPIO.output(Motor2B, GPIO.LOW)
GPIO.output(Motor2E, GPIO.HIGH)

And this is backwards.py

import RPi.GPIO as GPIO
from time import sleep

GPIO.setmode(GPIO.BOARD)

Motor2A = 21
Motor2B = 23
Motor2E = 19

Motor1A = 16
Motor1B = 18
Motor1E = 22

GPIO.setup(Motor1A, GPIO.OUT)
GPIO.setup(Motor1B, GPIO.OUT)
GPIO.setup(Motor1E, GPIO.OUT)

GPIO.setup(Motor2A, GPIO.OUT)
GPIO.setup(Motor2B, GPIO.OUT)
GPIO.setup(Motor2E, GPIO.OUT)

print("ON")
GPIO.output(Motor1A, GPIO.HIGH)
GPIO.output(Motor1B, GPIO.LOW)
GPIO.output(Motor1E, GPIO.HIGH)

GPIO.output(Motor2A, GPIO.HIGH)
GPIO.output(Motor2B, GPIO.LOW)
GPIO.output(Motor2E, GPIO.HIGH)

If you see this diff https://www.diffchecker.com/skmx6084 you can see the difference

My small robot has two motors controlled by an L293D and that is controlled via a Raspberry Pi. They will both go forwards but only one will go backwards.

I've tried different motors and tried different sockets in the breadboard, no luck. Either the L293D's chip is broken (but then it wouldn't go forwards) or I've wired it wrong.

I followed the tutorial, Controlling DC Motors Using Python With a Raspberry Pi, exactly.

My small robot has two motors controlled by an L293D and that is controlled via a Raspberry Pi. They will both go forwards but only one will go backwards.

I've tried different motors and tried different sockets in the breadboard, no luck. Either the L293D's chip is broken (but then it wouldn't go forwards) or I've wired it wrong.

I followed the tutorial, Controlling DC Motors Using Python With a Raspberry Pi, exactly.

Here is a run down of what works. Let the 2 motors be A and B When I use a python script (see end of post) both motors go "forwards". When I change the values in the Python script, so the pin set to HIGH and the pin set to LOW are swapped, motor A will go "backwards", this is expected. However, motor B will not move at all. If I then swap both motors' wiring then the original python script will make both go backwards but swapping the pins in the code will make motor A go forwards but motor B won't move

So basically, motor A will go forwards or backwards depending on the python code but motor B can only be changed by physically changing the wires

This is forwards.py

import RPi.GPIO as GPIO
from time import sleep

GPIO.setmode(GPIO.BOARD)

Motor2A = 23
Motor2B = 21
Motor2E = 19

Motor1A = 18
Motor1B = 16
Motor1E = 22

GPIO.setup(Motor1A, GPIO.OUT)
GPIO.setup(Motor1B, GPIO.OUT)
GPIO.setup(Motor1E, GPIO.OUT)

GPIO.setup(Motor2A, GPIO.OUT)
GPIO.setup(Motor2B, GPIO.OUT)
GPIO.setup(Motor2E, GPIO.OUT)

print("ON")
GPIO.output(Motor1A, GPIO.HIGH)
GPIO.output(Motor1B, GPIO.LOW)
GPIO.output(Motor1E, GPIO.HIGH)

GPIO.output(Motor2A, GPIO.HIGH)
GPIO.output(Motor2B, GPIO.LOW)
GPIO.output(Motor2E, GPIO.HIGH)

And this is backwards.py

import RPi.GPIO as GPIO
from time import sleep

GPIO.setmode(GPIO.BOARD)

Motor2A = 21
Motor2B = 23
Motor2E = 19

Motor1A = 16
Motor1B = 18
Motor1E = 22

GPIO.setup(Motor1A, GPIO.OUT)
GPIO.setup(Motor1B, GPIO.OUT)
GPIO.setup(Motor1E, GPIO.OUT)

GPIO.setup(Motor2A, GPIO.OUT)
GPIO.setup(Motor2B, GPIO.OUT)
GPIO.setup(Motor2E, GPIO.OUT)

print("ON")
GPIO.output(Motor1A, GPIO.HIGH)
GPIO.output(Motor1B, GPIO.LOW)
GPIO.output(Motor1E, GPIO.HIGH)

GPIO.output(Motor2A, GPIO.HIGH)
GPIO.output(Motor2B, GPIO.LOW)
GPIO.output(Motor2E, GPIO.HIGH)

If you see this diff https://www.diffchecker.com/skmx6084 you can see the difference

Fixed minor typos and inlined the link
Source Link
edit approved Feb 1, 2016 at 14:32
Greenonline
edit approved Feb 1, 2016 at 14:32
Greenonline
  • 1.7k
  • 6
  • 21
  • 32
Tweeted twitter.com/StackRobotics/status/694165099217604608
Source Link
Hamzah Malik
Hamzah Malik
  • 123
  • 1
  • 10