Arduino woes

[Horwig]

I've posted this on the yahoo group, but I'll post here as well.

Focuser stopped working mid session the other night, and I can't fathom it out, it's definately not harware.

I'm totally confused, sometimes everything works, then it stops.

I've modified the 'blink' sketch to drive the motor, which works every time,

however, when I upload the focus driver, it sometime works, but most times doesn't,

but I can see the rx/tx light working on the uno, so focus software/arduino are talking, just no output from pins 2,3 or 4.

There must be a patern to what goes wrong, I just can't see it.

It's standalone 2.00.00C on windows 7, arduino uno running version 23. Focus driver 2.0.0I

The sound you hear is the intense scratching of head...

Huw

[Reggie]

copy and paste the pde that you are using for your control, go to pastebin.com, paste the pde into pastebin, click the submit button, paste the resulting link in here, lets check and see that the pde has actually got the right numbers in it

[Horwig]

Thanks Reggie, I'd already re downloaded the pde, so assume it's correct. I'd ordered another chip from Technobots, so I've just tried that in my present uno, now everything works again. As I said, tx/rx lights were showing activity, but with this chip activity looks different, so I don't know what's different, should I try re-burning the bootloader?

Half of me wants to know what went wrong, the other half says, leave well alone, it works now.

Thanks again,( I really should buy that book).

Huw

[ncjunk]

So you have it working? I've been following all your posts on yahoo but didnt have anything new to add to the other guys so kept quiet.

I'm interested in what the problem is as well!

Enviado desde mi GT-I9003 usando Tapatalk

[Reggie]

Which chip did you order from technobots? the atmega328? Either way you don't need to touch teh bootloader, it's on a seperate chip

I am at a loss as to why it just stopped working, unless the chip is damaged, it's quite possible that pins 2 or 3 were damaged but I'm not entirely sure how, unless there was an issue with the driver board and you unpluging the stepper motor with the coils still energised (there's a warning on the polulu motor driver page about that). That having been said, unless the polulu board managed to short the motor power and the controller power I can't see it being from something like that. Other alternative is that there was a possible short due to moisture that killed the pins on teh chip? or possibly the motor driver tried to pull too much power through the dir/enable pins, you could try putting a 1k resistor between the pin 2 and the step pin, pin3 and the dir pin?

Maxstep in the pde could also cause an issue that might look intermittent to the untrained eye too, depending on the current position of the stepper and the direction and number of steps needing to be taken.

regards,

Reggie.

[Horwig]

Thanks Reggie Neil, thanks for your patience, I really am stumbling around in the dark (that book is well overdue, btw, which would you recommend?). Yes, the chip was the atmega328, What was confusing me was that I changed the 'blink' sketch to pulse all the pins, and they all worked, even ramping up the pulse freq to drive the stepper worked, and so I assumed that all the hardware worked.

So the uno was receiveng the pde correctly from the pc, but not being controlled by the standalone focus software. What is different with the new chip is the seq of the flashing rx/tx lights on the board when commands are sent.

I think the suggestion of current limiting resistors is good though, whatever happened, it was in the cold and damp, so it can't do any harm.

Thanks again,

Huw

[cowasaki]

Which chip did you order from technobots? the atmega328? Either way you don't need to touch teh bootloader, it's on a seperate chip

??

The Atmega 328p has 32K of Flash which contains the program code. The boatloader is written onto this Flash storage at the beginning and is the software used to allow the 328p to talk to another computer for the 'program' to be uploaded.

I have built a number of devices from scratch using the 328p and the larger 1284p if anyone has any questions about them or needs help with the electronics or programming side then just shout. I have a MEGAUK circuit board manufacturing setup so use this regularly.

If anyone needs Eagle files for the basic board etc again just shout.

[cowasaki]

I'm new here so not really sure how much use people would make of it but if there is a genuine interest I would be more than happy to do a thread Eagle/Arduino setup, getting it working as a stand alone setup, using an LCD, IO and programming.

[Reggie]

My bad, I mistakenly thought that the arduino uno(horwigs arduino is an uno) put the bootloader on the 16u2 chip.

As you've mentioned, building arduinos is pretty easy, best resource I've found for building your own is this:

Physical Computing at ITP | Tutorials / Setting up an Arduino on a breadboard

Very easy and useful for prototyping.

[cowasaki]

My bad, I mistakenly thought that the arduino uno(horwigs arduino is an uno) put the bootloader on the 16u2 chip.

As you've mentioned, building arduinos is pretty easy, best resource I've found for building your own is this:

Physical Computing at ITP | Tutorials / Setting up an Arduino on a breadboard

Very easy and useful for prototyping.

That saves me a job. Just looked at that and it looks like what I would have done. If anyone is interested in setting up Eagle and doing their own proper boards I am happy to put something together including a set of schematic/board files. This is the result of my current arduino project :

[Reggie]

Looks like a laser, light or sound activated camera trigger?

[cowasaki]

Looks like a laser, light or sound activated camera trigger?

All of the above and more besides