Tutorial SMC3 Arduino 3DOF Motor Driver and Windows Utilities

you're right. image is changed

Yesterday I got the IBT-2 bridges. As I expected theses bridges are the 43A ones and not the 7970B . Nevertheless I wired one of them to the Arduino including the two pots. Later I uploaded the SMC3 code to the Arduino (MODE2):

Code:

// Set to MODE1 for use with a typical H-Bride that requires PWM and 1 or 2 direction inputs
// Set to MODE2 for a 43A "Chinese" IBT-2 H-Bridge from e-bay or equiv

#define MODE2  

// #define REVERSE_MOTOR1

The potentiometers are working fine (SMC3 utility), but there is no output to the motors at all. Remark: I switched a jumper on the pins 3 and 4 and connected it by using a jumper wire to the Arduino. Only one bridge is connected.

What did I do:

Bridge to Arduino (Number of the pin):

RPWM -> 2 (PMW)
LPWM -> 9 (PMW)
R_EN + L_EN -> 3 (PMW)
VCC (5V, checked, all connecnted)
GND (not all connected together, I used all three pins onto the Arduino)

http://www.hessmer.org/blog/2013/12/28/ibt-2-h-bridge-with-arduino/ Interesting article I could try and find out if the bridges are working using th other example if nobody else knows what the problem could be.

Hi Pit, you might check with another member who is using this code and those drivers successfully. Here is his build thread:

http://www.xsimulator.net/community...-wood-to-steel-2dof-platform.5380/#post-55608

I got it!!!

RPWM -> 2 (PMW)
LPWM -> 3 (PMW)
R_EN + L_EN -> 9 (PMW)
VCC (5V)
GND

@Historiker: you should update the very first page of this thread. PS: I mean @RufusDufus as the thread starter.

Hi Pit, glad to see you got everything going and without assistance! I will investigate this one a bit further as I use these H-Bridges and the details on the first page were taken from that setup - maybe I translated wrong?

I'm pretty sure the way you have wired though the motors won't change direction correctly while in MODE2 - I believe with this wiring you want to be in MODE1 and it will drive that particular H-Bridge in drive/coast mode instead of drive/brake mode (which is OK).

Anyway if it is working, that's great, maybe as you say I have translated the pins somewhere in the first post - I'll let you know what I find out when I have a closer look.

@RufusDufus: I have to state the "got it" more precisely... yesterday I built only a test unit and connected a power meter to the bridge. I do not know yet if all goes well so perhaps it would be too early to say "I got it". By the way I think I am on the way. Tomorrow the test unit should be ready and I can give you more information.

I've checked the code and the wiring diagrams in the first post and they appear correct. For clarity here is the correct wiring for MODE2 with the IBT-2 H-Bridge including the pin numbers for both:

MOTOR1
Arduino Pin 2 M1 ENA --------> H-Bridge Pin 1 IN1 (sometimes labelled RPWM)
Arduino Pin 3 M1 ENB --------> H-Bridge Pin 3,4 EN1, EN2 (sometimes labelled R_EN, L_EN)
Arduino Pin 9 M1 PWM ----------> H-Bridge Pin 2 IN2 (sometimes labelled LPWM)

MOTOR2
Arduino Pin 4 M2 ENA --------> H-Bridge Pin 1 IN1 (sometimes labelled RPWM)
Arduino Pin 5 M2 ENB --------> H-Bridge Pin 3,4 EN1, EN2 (sometimes labelled R_EN, L_EN)
Arduino Pin 10 M2 PWM ----------> H-Bridge Pin 2 IN2 (sometimes labelled LPWM)

If it helps here is a basic drawing of how these H-Bridges work.


The L_PWM and R_PWM determine whether +12V or GND will be connected to each of the motor pins. The EN_L and EN_R inputs determine if the motor pin is connected through or left open circuit. So there are various ways to drive the bridge, typically you put a PWM signal on one of the PWM pins and switch the other to ground and then to reverse the motor you swap the signals to these pins. In this case you can just leave the EN pins switched on.

Because of the way I setup the SMC3 code it wasn’t easy to just swap the PWM signal to another pin so I leave it on one but switch the other between +12V or GND depending on the direction I want. But in doing this you also have to invert the PWM signal as well – which is the same as swapping the duty cycle: INV_PWM% = 100% - PWM%. (MODE2 does this inverting of PWM) Again in this mode you can leave the EN pins always on.

Another way of driving it is to use the PWM inputs as the direction pins and just switch them to +12V and GND depending on the direction you want. And then you put the PWM signal on the EN pins which effectively switches the power on and off rapidly to the motors. This is normally referred to as drive/coast mode as it doesn’t apply any braking to the motor. If you use the connections you have given above with MODE1 you will be running the H-Bridge like this. The only disadvantage of using this mode with this particular H-Bridge is that the EN pins are also used to reset the protection circuitry so by applying the PWM to these pins effectively resets the protection at the PWM frequency making it ineffective.

@RufusDufus thank you so much for sharing your thoughts and information. I have to analyze all for now.

I am a little unsure, I wired now exactly what you have written but only MODE 1 works for now. No matter why but if it works it works for me Certainly I will get things straight later if something was not clear or wrong.

First impressions after one day wiring, testing and lost time...

1. One of the bridges (first one) is not working properly. The fan of the power supply slows down when a motor begins to turn.
2. After a few rounds of testing a winches stopped abruptly. Then I heard a noise from the other bridge (second one) like a little hiss. Now nothing works.

An experience more ...the moto monster is not so bad! It shuts down right in time if the load is too much to prevent damaging. IMO the IBT-2 is not worth the few bucks.

UPDATE: what a mess, the bridges are different! One is the BTN7960B and the other one ist the BTS7960B...no wonder. Never buy in a shop you don't know.

Bad news! Sounds like there may have been a manufacturing issue perhaps? The BTN and BTS devices shouldn't be that much different.

How did you end up driving them MODE1 or MODE2... did you notice my comment above that MODE1 would effectively disable the protection circuit on the IBT-2?

The Monster Moto's use the same output driver as the JRK12v12 that have proven to be very reliable. So apart from the Arduino having a different PID algorithm to drive them they should be pretty tough boards. If you have them they sound like a good option.

MODE1. No problem at all these bridges are limited and no progress in comparison to the monster moto. My experiment was to push the limit of the IBT-2.Finally they are not "better". I will go ahead with the monster moto by using both channels for one winches if possible.

@RufusDufus if you are willing to develop the code for sabertooth 2x60 I will spend you all my coins I have

Don't worry about the coins... I will have a look at the datasheet and see what is required.

You just can't get enough power can you!

Hi Guys,
I'm using 2 x IBT-2 with a arduino mini pro clone with the great software from RufusDufus and for the time being it works without a problem.
The motors i have are from a old golfcar (350W/24V) and concected them on a 12V powersource.
I'm now fiddling (struggling) with simtools to get it working with LFS

Looking for some help now
All is running fine now with SMCUtils (hardware is Arduino Mini pro and two IBT-2's), real smooth movement without any problems,
But when i use Simtools and made a profile like the example (saw & surge) i can move the axis in output testing.
Then i'm using the game LFS and the default profile then there is no roll or pitch, what did i overlooked???

Hi @dedas do you record any data into the tuning center?

Yes i did get al sorts of data in the tuning center, and i can see the virtual axis moving.
There is data comming out of the game, seems to me that saw & surge is working but i have no roll & pitch some how