How does diablo distributes power to motors?

Hi!
We have been running some new tests, with new and improved configuration. And we have stumbled upon a under-voltage problem with the diablo boards. The motors run smoothly when they are not loaded. But as soon as we put the robot down and there is some load on the motors and we measure the voltage we don't get the minimum 23.8V volts that are needed to run the motors efficiently. What would be the code for setting the minimum voltage? Or setting the lower drive power? (Note: motors are new and in excellent condition and all wiring is done correctly. Also battery is very powerful and can supply the need power.)

Hi!

Well the battery can provide 430A of cranking amps. So I don't think that that is the problem. The stats are following ( if it will help at all) We have 4 * 500w 24V motors. The robot weights now approx. 110kg. It has also 1.8 gear ratio with chains.
I'am thinking of a code that would make Diablo boards provide from the start the required 24V to the motors as soon as I command it to go forward. Would seeing the code help you?

Hi! Sorry that it took me this long to answer and put some measurements, but I was on a business trip, and now I'am back with some data :). So I did the measurements as you asked and I got the following readings:
1) When battery is connected the voltage from the batteries is 24V at Diablos battery connection points. SO there is no power loss there.
2) When the motors are moving without load the readings starts from 0V and goes up to 18,7V before the motors stall.
3) When there is load the motors manage to get about 5 volts before they stall.
4) With power of 50% I get only 9,8V volts out
5) With 75% power I get 15V out.
With basic calculation: for the motors to work properly the window is 19V absolute minimum and about 27V for maximum (If we don't want to overcharge them)
If I'am getting this correct we should be able to tell the Diablo board to start operating the motor from 20V and up. How exactly do I do that? O r is there something else to do? What I'am missing here?

Yes the first one is from the battery when the motors are not powered.
And the rest is taken from the motor connection points at Diablo.
Can you tell me why this two measurements should be taken from the battery also? If the battery is feeding constant 24v even while the motors are running...

I did the measurments and the drips are the following: when unloaded and it uses 50% of power it drops from 23.7V to 21.5V. And I get the same drop when loaded and I use the same power. Well I need to charge the batteries obviously. But still the voltage drop isn't that big.

Well I charged the batteries and measured all the things again. So now that it is fully charged it has a charge of 25.6V. When loaded it drops to 23.8V. It is still slugish and powerless. We then tryed to overcharging it and made it 36V system. With same results. The voltage drop is about 2V but the robot just wont move well in any direction. And what is more strange it is that when I try to drive it backwards it will shutdown after a while. I'm not sure anymore what to do... I asked a electrician to check all the wiring on the bot and he said it was done well and corectly. Batteries are AGM motorcycle batteries that shoyld provide enough juice to the system. So what could be the problem? Do you still think that the problem are the batteries? Or could it be something with the code?

Lets make an addition to the previous post. I switched one Diablo board with a Sabertooth 2x32A and connected just two motors to it. The robot worked perfectly with just two motors running! So now I'am more than sure that the problem is not with the batteries or connections but with the Diablo boards! I really want to know what might be the problem with them. Because they are easier to use with Rpi than Sabertooth. But if we won't come up with a solution to the powerlessness of Diablo board I will change the whole system to be operated with Sabertooths. I'm little disappointed with the Diablo board performance...

yes I have. And still the Sabertooth works well without any issue. This is the piece of code that I use to control the motors with Diablo. i use a Xbox controller and its joysticks in a similar way that you do with your Doodleborg and PS-controller. This is the code that has worked the best so far.

The script that contains input handling is also responsible for parsing input data from a serial connection, so I'm going to omit some parts for clarity's sake. I can dump the whole thing if you feel like it'd help.

Motor controller initialization, where the unnamed params are: 1. DIABLO1 address, forward speed limit, backward speed limit

motor_controller = motor_controller.MotorController()
#init motor controller with diablo boards at pins 31, 32, 33
motor_controller.Init(0x31, 1, -1, diablo2address=0x32, diablo3address=0x33)

Here's a snippet from the main loop that parses input data as well as sends it to the motor controller.
Valid values for leftstick or rightstick is something between -1 and 1. A value that could get send to the motorcontroller is, for example, 0.57575757579, or -0.1467958695.

while True:
#  get values from xbox controller from the sender side and use the values to operate the servos/motors
    message = ser.read_until() #searches for \n by default
    message = message.decode()
    
    marker = message[0:4] #this variable will hold the marker string of the message
    body = message[4:-1]

    if bodylength == 32:
        if marker == "MSG3":
            leftstick = ParseBinaryToFloat(body)
            print(leftstick, " left")

        elif marker == "MSG4":
            rightstick = ParseBinaryToFloat(body)
            print(rightstick, " right")

    motor_controller.DriveLeftSide(leftstick)
    motor_controller.DriveRightSide(rightstick)

It gets sent to the motor controller class as is. The motor controller in turn sends the raw input data to one of the connected diablos. The diablos have two motors each and are responsible for controlling the the robot's left and right banks.

    def DriveRightSide(self, speed):
        self.DIABLO3.SetMotors(speed)

There are a total of three diablos connected, with DIABLO1 driving the motors on the left bank and DIABLO3 driving the motors on the right bank. DIABLO2 doesn't perform any function related to actually moving the robot, so we'll ignore it.

As for the wiring, they're daisy chained according to some official material I found on this page.

Edit: corrected some incorrectly explained stuff.

What would be the best way to do that? How can I turn that logic off?
In a sense I've already done as you suggest because the motors get input from a gamepad's analog sticks, and I've tried tilting slowly from zero to maximum without success.

Yes I tried and the result was exactly the same as described before...
I tried different variations to slowly increase the motor inputs but still nothing. It will move just a litle bit after whitch the motors will stall and they don't seem to work well under load with diablo board. But with Sabertooth everything works so smoothly, exactly as it was designed to work. Do you have any other suggesrions what might still be the problem?

No. they don't seem to get any hotter or warmer than what they are when they are on.

So what do we check next?

Hi!
So after a long break we tried out your latest diablo test code. Well we got out some results that were better than the previous ones. We put the code on and let the robot run out in the garden as it wanted and at the same time we followed it and looked at the data that it was putting into the terminal. So basically it did run smoothly up until 54% power. After which it shut all the motors down. And basically stopped working. It continued to print the motor power but it was just zeros, We tried it also with remote control program, imitating the way you reset the motors, and got the same result. So what next? Could it be that Diablo just can't handle the power for the 500W motors? Because we tried Sabertooths right after these tests and it worked wery well.

Hi!
I attached a picture to this to answer your question, So what does it tell you?

So here are the results for the second test. What next?

Hi!

So basically, if I just connect a BattBorg to mine Rpi 3B+ GPIO's and use AA batteries with it, then that should do the trick? Can BattBorg give enough power to a RPI 4?

Hi!
A small update. So we made some radical changes so to say. We changed the 500w motors to 350w geared motors, and changed the chasis structure and lighteden it alot. Now it runs extreamly well, as it should. We didn't use the 5v power supply in current configuration. But if we will change back to the 500w motors, we will put it in the system also. I will update you on how it goes later on :). Thank you for your support

Hi!
I want to ask now how I should connect the Battborg, when I have multiple diablos and ultraborgs daisychained togheter. How exactly I shouöd connect the Battborg to Rpi? Because now if I just connect the power pins to rpi, the rpi will work bust fine but it wont find the diablos etc. So how exactly I connect them now?