Some Titan Questions

[jrothr...@hdsd.org]

I received our Titan the other day, and I have a few questions as it did not come with any literature.

1) Does anyone know if/where there is a datasheet/documentation about how to use it? I understand most of it, but would like to have some literature for the students (and it would help answer some of the following questions).

2) Is it possible to just use it as a PDP and use it to power other motor controllers? If so, how do you recommend setting that up?

3)Is it safe to do voltage regulation with it (would it be safe to drive 10v motors) if I set current/ voltage regulation in software (those methods seem to be exposed)? 

4) Does anyone have a recommendation of a voltage regulator to take the second 12v output and lower it to 7 volts so I can power additional Vex motor controllers (and motors) for mechanisms?

This too is wonderful hardware.

Thanks,

Jacob

[Scott Libert]

I believe Studica is still working on the setting up the support channels for Titan.  For now, please direct technical questions specifically on Titan to:

James....@studica.com 

Cheers,

- scott

[Charlie Peppler]

Jacob,

I have also received the Studica robot (Titan, frame, mecanum wheels, batteries, pre-wired), and had the same question.
I contacted James (see Scott's reply), and they are indeed working on documentation.

I took the unit out of the box, and started with Kaden's example here --> https://github.com/kauailabs/VMX_WPILib_Examples/tree/master/java/TitanQuadNavXMecanum

I fired it up, but it didn't work properly.  The motors kind of twitched and bucked.  It had the look of a PWM signal frequency issue.

I contacted James, and he said he used different values for the TitanQuad constructors during his testing.  He used the following values (note the addition of the middle parameter, 

at a value of 15600 on the TitanQuad constructor):

and then:

I fired the bad boy up, and it drove around like nobody's business.  Full Cartesian motion utilizing the NavX gyro out out of the box!  Easy peasy lemon squeezy.

Now, you sound like you want to pull the Titan apart and do different stuff with it, which entails question I can't answer, but if you want to drive
the Studica robot around, that's all it took.  Cool beans!

(Note to Scott, you might ask Kaden to talk to James about the values in his TitanQuad contructors in his example to match that of James, to simplify

startup for other clients) 

As far as lowering voltage from 12->7, the closest I can offer are a variety of Buck/Boost products I've used on previous RasPi robot projects
I've worked on.  I have at least two that dropped 12V down to either 5 or 6 volts, but not to 7.

Here's one from Adafruit (Buck/Boost to 5v) --> https://www.adafruit.com/product/2190

Here's another one I found a while ago, that Bucks from 12V down to either 5 or 6 (switchable).  Handles 3amps.  --> https://www.amazon.com/Ship-Hobbywing-Switch-mode-UBEC-Lowest/dp/B008ZNWOYY

I'm sure if you look around, you can find one that gets you to 7, at the amperage level you need.

Hope this helps.

Charlie

PS.  If you're using windows, try "Snip and Sketch".  Great way to snapshot your screen/code examples, mark them up, copy and paste right into an email.  Quick and easy!

[jrothr...@hdsd.org]

Thank you all for your replies. I had initially thought that the  OSOYOO base motors had a max voltage of 9V.  Today I received an email from the team that makes the kit, that they do tolerate 12V :).  I did ask James about my few remaining questions, but this combined with an email from Derek at Studica answered most.

The PDP function is mostly directly linked to the motor outputs. There is the two (one will go to the VMX of course) outputs, but they have a max output of 10A, so that is not really tenable for the spark Max. However, for the vex EDR with a buck converter, they should work well. 

We only bought the Titan and not the full robot package as we have many Vex kits. 

Charlie, Thank you for the code hints and the idea to use Snip and Sketch. I will do that moving forward. Do you know what the 42 and 15600 represent?

I am making a lot of progress thanks to you all. 

~Jacob

[Charlie Peppler]

On Saturday, July 25, 2020 at 6:49:35 PM UTC-4, jrothr...@hdsd.org wrote:

[...]

Do you know what the 42 and 15600 represent?

I know the 42 was the default CAN bus address that James was using for the Titan.  The extra
parameter (15600) just made it work.  Lack of documentation leaves me only guessing like you.

I have a question for you Jacob.  When using the Pixy(2?) and the Pseudoresonance Java API,

did you end up using the SPI or the I2C link?  The docs warned that the I2C interface was untested,

but I know you upped your I2C baudrate per Scott's direction. 

[jrothr...@hdsd.org]

Thanks. That makes sense. 

I used I2C. I still could not get SPI working correctly. I did up the baud rate of the Pi as Scott suggested. That seemed to do the trick. 

[jrothr...@hdsd.org]

The 15600 is the frequency of the PWM.  If you do not include it, VsCode does not read it as an option in the constructor, but once you do, it shows up in the linting. While not as verbose as IntelliJ, I do find VScode's IntelliSense helpful. So,I guess, if the default was the wrong frequency, it makes sense that the default seemed like a bad PWM signal.