Thoughtstream works until I plug it to USB, then it gives error and exits

[brunoloff]

Hi,

I recently started programming an app for thoughtstream --- thanks andy for sending me the protocol spec, I hadn't even realized this forum existed at that point. It was all working fine until a few hours ago the following weird thing started happening:

The thoughtstream works fine with batteries, but when I plug it to the USB it starts flashing an error (and eventually automatically turns of). If I plug it out before it turns off, it resumes operation just fine.

Also, if, while it is plugged into the usb, I place it on a very low-resistance conduct (I was using mineral water on a sheet of paper, apparently 50 KOhm, compared to the typical 200 kOhm on my skin), then it starts working just fine.

What could it be?

[Andy]

Hi,

I recently started programming an app for thoughtstream --- thanks andy for sending me the protocol spec, I hadn't even realized this forum existed at that point.

You're very welcome. And welcome to the forums!

It was all working fine until a few hours ago the following weird thing started happening:

The thoughtstream works fine with batteries, but when I plug it to the USB it starts flashing an error (and eventually automatically turns of). If I plug it out before it turns off, it resumes operation just fine.

Also, if, while it is plugged into the usb, I place it on a very low-resistance conduct (I was using mineral water on a sheet of paper, apparently 50 KOhm, compared to the typical 200 kOhm on my skin), then it starts working just fine.

What could it be?

That's a strange one!
Can you check the voltage of your USB connection?
Try another USB cable and/or a USB power supply in place of a computer USB connection?

[brunoloff]

You're very welcome. And welcome to the forums!

That's a strange one!
Can you check the voltage of your USB connection?
Try another USB cable and/or a USB power supply in place of a computer USB connection?

Ha, here is something really odd:

I happen to have a self-powered USB hub. If I power the Thoughtstream with it, without connecting the hub to the computer's USB port, it works fine. The instant I connect it to the USB port, it goes into error mode (actually the lights get all red for a few seconds before they start blinking red yellow green).

[brunoloff]

Here is something really weird: after plugging in a USB disk drive to the USB port and trying again, it works once more! Why?!!

[Andy]

Ha, here is something really odd:

I happen to have a self-powered USB hub. If I power the Thoughtstream with it, without connecting the hub to the computer's USB port, it works fine. The instant I connect it to the USB port, it goes into error mode (actually the lights get all red for a few seconds before they start blinking red yellow green).

So if powering it from another source works fine, it sounds like there's an issue with the USB port on your computer.
Try another computer and see.

[Andy]

Here is something really weird: after plugging in a USB disk drive to the USB port and trying again, it works once more! Why?!!

It still sounds like something's fishy with the USB ports on that computer. Try another computer to confirm.

[brunoloff]

I can confirm that it had something to do with the USB port. The hardware worked fine when plugged into another computer.

Also, I found that the problem would go away if I would plug my external hard-drive into the USB port, eject it, and plug in the Thoughtstream USB again.

So a major show-stopper became a mere occasional minor annoyance.

Thank you Andy for the feedback,
Bruno