...a most likely dumb question

Robotics and electronics discussion Software and microcontrollers
1

Hi all,
I’m fairly new to the Baby O (blue), but I’ve accomplished a lot in the last few weeks. I’ve gotten to the point of now trying to break away from the bread board and controlling the Baby O in a stand alone circuit.
The problem I’m having is that I have discovered that the Baby O won’t execute code if the USB programmer is disconnected. When it is connected it works fine…not connected…not fine.

What is it that I’m missing here? At this point all that I want to do is download the code into the baby O, disconnect and let her run. There’s got to be something I’m not doing.

Btw, I’m using Studio 4.

Any help would greatly be appreciated.

Thanks!

David

2

Hello.

I have a few questions that will hopefully help me narrow down the problem:

  1. What is your Baby Orangutan programmed to do? What cues tell you that it’s working or not?
  2. What are you using as your Baby Orangutan’s power source and how is it connected to your Baby Orangutan?
  3. Do you have anything connected to the Baby Orangutan’s reset line?

- Ben

3

Thanks Ben,
As it turns out I was right…re: “it was probably a dumb question”. Right now both circuits are working…the breadboard and the actual. I can’t explain what the problem was, I was panicking thinking it was a setup error in Studio or something.

The circuit is driving a stepper motor on 12 vdc nicads. After initialization, I have the stepper locate the limit switches (180 degrees apart), then center between them. The reset line is tied high with a 4.7K resistor. The problem was that only when the usb programmer cable was connected would it run the code. If I disconnected it (after downloading the code to the Baby O), powered off, and back on,it would not run the code…no stepper movement. If I reconnected the usb programmer cable, powered back up, it would then work and execute the code.

Strange… it did this in both the breadboard circuit and the stand alone circuit. I can’t explain it.

David

4

Hey David,

I can’t see how this could be causing your code execution trouble, but you don’t need an external pull-up resistor on the reset line, there’s 10Kohm pull-up resistor built into the board. If anything, the lower parallel resistance could have kept you from being able to program the Orangutan in the first place, the AVRISP mkII programmer is unhappy if the pull-up resistance is less than 4.7Kohm. I’m guessing you’re using a Pololu USB programmer then?

Anyway, glad to hear your setup is working now, although problems that go away for no apparent reason can be the most frustrating! I’m also glad that someone is already putting the new Baby O B to work as a stepper motor controller, what are you actuating with it?

-Adam

5

Hey Adam,
Yes, I’m using the Pololu programmer, it does a fine job. I don’t think the pull up caused any of the problems. When the problem was 1st encountered, I didn’t have the reset pin tied to anything and only added it to possibly eliminate it as a source of the problem…it didn’t.

Anyway, it all works now, still confused…but.

I’m using a TI L293D and driving a unipolar stepper from it. The application is a solar tracking device. The stepper code really turned out to be simple , very efficient and fast. Works like a charm and the Baby O is quite happy with it…so far.

Thanks

David