Smoking PING)))) sensors

I didn't get arround playing a lot with my bot due to work/studie untill yesterday. Nothing changed and last time I used it all was fine and roaming (as shown in the video). So last night I had a visitor and wanted to show the bot, power on, but no movement. 2 seconds later smoke was comming out of the left and right ping (the little chip under the cq passed sticker turned to toast). I switched things off and checked for something that could cause a shortcut but all seems hooked up fine.

Anyone ever seen such a thing?

Hi DutchBot,Maybe one of

Hi DutchBot,

Maybe one of your voltage regulators is damaged or short-circuited. Which ultrasonic range finders are you using? Normaly they need 5V. I would start to meassure the voltage between ground and voltage supply line of the PING)))).

Have you tested it before?

did it work fine?

 

what did you do differently?

Very strange, nothing

Very strange, nothing changed and yes it worked fine. After running it last time I just stored it on my desk for a week or so, last night i switched it on and it started to smoke. I’ll check the voltage tonight. Crap man.

i’d bet on a damaged voltage regulator

A short is possible, but you tested it… are there any loose wires? maybe it was just a temporary short?

hey DutchBotIve had the same

hey DutchBot

Ive had the same problem. its when theres an over supply of voltage/current to either the signal wire, or the supply wire of your ping))). The ping))) is a brilliant piece of equipment but very very sensitive. I learnt that the hard way. Twice.

When i build my robots, the ping))) is always the last thing i put on after testing the voltages.

Even worse

Well looks like the whole board is fried, not only the pings. I double checked all wiring (it’s not much) but all seems fine. Maybe the Lipo went bananas for a second. Really don’t know. I’ll probably sent it down to the guys of parallax (emailed them already). Only thing that was hanging loose was the usb cable but it sat on the laptop (plastic casing).

Still strange the whole thing went down including the prop chip.

ah man, that really is

ah man, that really is unfortunate…  :(  So were you running the Lipo cells direct or were they going through a Vreg(LVD if anything) as well?

They go straight into the

They go straight into the MRS1 board. It can handle anything up to 24 volts. Guess I’ll wait for the parallax guys, maybe they can take investigate it properly (as i don’t have any fancy tools).