Tutorial Arduino code for 4DOF and 1 DIRpin Hbridge board

Hello,

1 PWMpin & 1 DIRpin H-bridge board
I've purchase H-bridge board to drive my motors in 24V but as you can see, there is 1 pin for pwm and 1 pin for direction!!
(25$ instead of 80$ for my Motomonster board @sparkfun https://www.sparkfun.com/products/10182 and 12V max).

ebay
(this ebay Hbridge is not good, too trials ended into smoke, choose Pololu instead for example).

As you can see, there is 1 pin for pwm and 1 pin for direction!!
-> in this topic you'll find the 2DOF code adapted to 4 DOF and 1 pins Hbridge boards.

edit 25 aug :
successfully tested with Pololu 755 single Hbridge driver boards = but 40 $ per motor ...
5.5 to 30 V voltage range and is efficient enough to deliver a continuous 15 A without a heat sink.
http://www.pololu.com/catalog/product/755





if you have a 2 pins Dir HBridge (like Sparkfun Motomonster),
INA1 INB1 PWM1 -> motor #1 OUTA1, OUTB1
INA2 INB2 PWM2 -> motor #2 OUTA2, OUTB2
use the original code here in resources section

Arduino Code for 4 DOF and 1 pins Hbridge boards
You can download the source code in the resources section!

You only have to open this arduino sketch (.ino) in the Arduino IDE and upload it into the Arduino board!

Arduino setup
- install manually the drivers (see the Arduino's specific documentation for Windows Seven installation).
- After complete installation, find in the Windows system on which COM Port it has been installed : you will need to put this information in SimTools / Interface Settings.


- Double clic on Arduino's line and adjust the default speed :


- In the Arduino plateform, put the right COM Port : if not, you won't be able to upload your program into the Arduino...


- Open the Serial Monitor (magnifying lens on top right ).


- Adjust here as well the same default speed :


Don't mess within the code ;-) or make everything coherent everywhere

Code:

////////////////////////////////////////////////////////////////////////////////
// INITIALIZATION
////////////////////////////////////////////////////////////////////////////////
void setup()
{
  // serial initialization
  Serial.begin(115200);

First hardware tests and WIRING

First : pot are not mounted onto the motor
you can see the expected behaviour in this video

and please find the explanation of the code here :

The code is written to put the simulator on middle position at start :
/* init position value*/
int DataValueL=512; //middle position
- if your pot is fully turned to max, as Arduino reads potentiometer value as motor position, Arduino believes that motor is in max position.
- but the order is to be in middle position
- so the Arduino will ask the motor to go reverse in order to go to middle position
- your motor is turning
- but while your pot keeps still, the motor will turn non stop !

- when you manually turn the pot backward to min, Arduino reads that motor is in min position
- but the order is still middle position, so Arduino will tell the motor to go forward
- motor runs non stop until the pot is in middle position

In the code, you have a tolerance parameter : when the pot is around middle position (<middle+tolerance and >middle-tolerance), the motor stops.
You can broader Tolerance value to stop your motor more easily manually.

Second : now checked the wiring
Once you have played in this manner, now checked the wiring
simulate the pot mounted onto the motor (back to back or alongside with gears...)
reduce the speed (pwmMax) to see the direction of motor rotation
and check if Arduino will behave as expected when you turn the pot

if your pot is mounted this way :


when you turn in a direction, motor has to go the opposite way.
If not, invert motor wiring or pot wiring.

Warning ! if you have gears between pot and motor, you'll have to twist your mind to check the correct behaviour.

Third : mount the pot onto the motor, the behaviour will be the following :
- motor goes to middle position and stop
- if you send order to Arduino via Serial Monitor (say R7FLAE) the left motor will move and stop at his new position ! right motor didn't move.
- etc...

2- calibrating the pot boundaries in the Arduino
const int potMiniRorL=300;
const int potMaxiRorL=700;
these values are convenient as they will always constrain the values whatever comes from the simulator software,
so the arduino will never send over-range value to the motors and your hardware will be protected !

Now without any game running ! send orders from Arduino serial monitor :

type the following strings in Hexa and press Enter:
R7FL7F
-> it should move the playseat in horizontal position

increase the angulation
R64L64
go farther cautiously
R3FL3F
if the playseat moves too little, then the potMini and PotMaxi are too close to middle position
and maybe go to max now : max backward tilt -> R01L01

- if it's too litlle check how much you can go further and decrease potMiniRorL, reupload and resend R01L01
and so on, until you found the pot minimal position

- do the same for potMaxiRorL, send RFFLFF and increase potMaxiRorL, reupload and resend RFFLFF

(write somewhere else these values that are associated to your particular playseat hardware).

3- find your pot amplifying ratio
- increase now the gearMotorRorLPotRatio (line 17)
- by default, it's equal to 1
- if you increase to 1,5 : the range will be increased by 50 %

no worries, if the amplifying ratio is too high :
- the playseat will not bump over the limits
- but the mouvments will be fast or jittering

Now, you can play with your DOFs :
type the following strings in Hexa and press Enter:
R7FL7F
-> it should move the playseat in horizontal position

increase the angulation
R64L64
go farther
R3FL3F
max backward tilt -> R01L01

R9BL9B
RC1LC1
RFFLFF (Max !!)
-> it should tilt the playseat forward and a bit further

for rolling movment, you have to mix the orders this way :
R3FLC1
R01LFF (Max !!)
-> roll left

RC1L3F
RFFL01 (Max !!)
-> roll right

SimTools Setup
- In SimTools : set the same ComPort and same Speed


- my Arduino code needs 8bits Hex data : just setup like this for 1 bridge and 2 motors


- startup and stop just send the instructions to come to middle
- and 7F in hex equals 127 in dec

if you want to use 4 motors :
R7FL7FY7FW7F
R<Axis1>L<Axis2>Y<Axis3>W<Axis4>
R7FL7FY7FW7F

if you want to use winds motor :
R7FL7FY7FW0 (no wind at startup or end !!)
R<Axis1>L<Axis2>Y<Axis3>W<Axis4>
R7FL7FY7FW0
For fun, the code is written in 3 DOF configuration + wind motor... but it works for 4 DOF.

Wiring Setup
Here are some high res pictures for plugging !









First run
- between your motors and the HBridge, you have inserted Fuses for safety

- but if you still wonder about the current needed by your motors under load
and if you want to protect your HBridge ;D
you can use the following functionnality inside my Arduino software :
reduce (scale down in fact) the motors's speed -> it will limit the intensity !

modify this line and try : 150 instead of 255 !
#define pwmMax 255 // or less, if you want to lower the maximum motor's speed

- measure the intensity and increase gradually max speed

Mat

With 2 motomonster and 1 arduino UNO or Nano, control 4 motors!!

Hello !

I've updated the post with the links : yes, it's ebay !

my 3DOF project is only at the beginning now
it will be a traction loss design ! 24V wiper motors and arduino, of course !

My previous 2DOF design + a traction loss base :
the classical approach just like the addon Simxperience simxperience.com/products

Mat

What is a wind motor?

@aarondc : it's a fan motor for blowing wind while driving !
As I bought 2 drivers board, I can drive 4 motors but I only need 3 !! So i figured out how to use the fourth :-D

@Raceray : I open a new post with my complete 2DOF project 2dof-xsim-arduino-wiper-playseat-t4616.html#p44019
For my new 3DOF project, I wish I could beta-test SimmTools.

A fan! What a great idea

wooow seams interesting... where did you get the wipers that runs at 24v? what car are from ?

how are you planning to feed them? a special power source or how?

nice project

@Ferslash : thanks !

I'll use the same motors as for my 2DOF playseat : you'll find the reference and link at the end of my post here
From AtoZ : 2DOF xsim arduino wiper playseat

Hi !

After some PM requests, I have updated the firt post of this topic with Arduino setup screenshots and SimTools Setup screenshot.

I'm glad ozyy53 has succeeded in using it ! :hi:

Mat

Mat, my own Chinese driver boards arrived today (same as yours). I am curious, what are the rest of the commands that you had Simtools send to the arduino?

Specifically:

Output range: 8 bits?, Decimal?

Startup output, Interface output, and Shutdown output?

Thanks much for working on this.

I am guessing that Interface-Output would be 1<Axis1>~0<Axis2>~ ?

Hi Historiker !

I'm editing my first post to give you the informlation you need ;-)

Ya quick RacingMat , did I get it right. :clap:

So to answer your question
Start up centres both axis. R7FL7F - Sim Tools R<7F>L<7F>
Send packet - Sim Tools R<Axis1>L<Axis2>
End packet is the same as the start no turning off command , mmm

[strike]I would tend to use 127 instead of 7F which is equal to 127 but not sure havent taken a close look at his code[/strike].
Didnt read close enough your using hex output for value
Correct me if wrong, I haven't plugged a Ard in to test it.

you're right ! :thbup:

- startup and stop just send the instructions to come to middle
- and 7F in hex equals 127 in dec

if you want to use 4 motors :
R7FL7FY7FW7F
R<Axis1>L<Axis2>Y<Axis3>W<Axis4>
R7FL7FY7FW7F


if you want to use winds motor :
R7FL7FY7FW0 (no wind at startup or end !!)
R<Axis1>L<Axis2>Y<Axis3>W<Axis4>
R7FL7FY7FW0

Here are some high res pictures for plugging !

Thanks gents! I made a quick trip (ok, 5 hours) and picked up the rest of my wiring and a spare Arduino so tomorrow I will do a test run.

Mat, I have two of the Chinese motor controllers. Is it possible to split the PWM and DIR and input for one motor to both sides of the motor driver? Then attach a single motor to both motor outputs? Would this allow a higher amperage output to the motor than a single side would?

Arduino code for 4DOF and 1 PWMpin & 1 DIRpin Hbridge board

Hum, it is not written in the specs, so i wouldn't advise you to test that !!
You are worried that much about intensity ?

Have you tried some more basic tests ?

Hi Mat, thanks for the quick response.

Since I have two boards and am only using 2DoF I just wondered if using both outputs from one board per motor would reduce the load on the motor driver. Although I am putting 15amp fuses between the motor drivers and the motors I thought this might give me a further safety cushion.

Aarondc suggested that I do this when I posted which drivers that I had planned on using. I am just not sure how to wire them in this manner.

Arduino code for 4DOF and 1 PWMpin & 1 DIRpin Hbridge board

Keep it simple and safe !
The KISS idea is :
- use 1 HBridge
- use your fuse
- limit the speed in the arduino program

I have updated my first post with this instruction :

you can use the following functionnality inside my Arduino software :
reduce (scale down in fact) the motors's speed -> it will limit the intensity !

1- modify this line and try : 150 instead of 255 !

#define pwmMax 255 // or less, if you want to lower the maximum motor's speed

2- measure the intensity and increase gradually max speed
Mat

Sorry to interfere in your discussion, but I strongly recommend not to connect the one motor parallel to two different bridge circuits.
Since drivers are never exactly equal, there is a greater probability of passing through current, which in turn can lead to failure of the h-bridge mosfets.

Regards...
Ale

Arduino code for 4DOF and 1 PWMpin & 1 DIRpin Hbridge board

Thanks ! You're very welcome with all your electronic knowledge
It's better with your words !