LPCXpresso IDE中的主题 Re: Lpc1769 really hot

Lpc1769 really hot

lpcware — Wed, 15 Jun 2016 23:33:25 GMT

Content originally posted in LPCWare by DjCracks on Tue Oct 30 05:02:27 MST 2012
Hi, I've been working with lpc1769 for a couple of months and recently I've encountered a problem. While testing the lpc in my system (a sumo bot) a led started blinking really fast and then just remained on. When i touched the lpc, it was very hot and de voltage regulator also. Now, this happens every time I insert the lpc on the bot and when I connect it to the PC both the target and the programmer get hot and the device not debuggable error shows up. Could it be a "too much usb power draw" related issue?
If anyone knows a solution, I would really apreciate his help.

Thanks.

Re: Lpc1769 really hot

lpcware — Wed, 15 Jun 2016 23:33:26 GMT

Content originally posted in LPCWare by Ex-Zero on Tue Oct 30 05:30:28 MST 2012

Quote: DjCracks
If anyone knows a solution, I would really apreciate his help.

Measure the voltage :confused:

Measure the current and / or reduce it :confused:

Re: Lpc1769 really hot

lpcware — Wed, 15 Jun 2016 23:33:26 GMT

Content originally posted in LPCWare by DjCracks on Tue Oct 30 05:42:01 MST 2012
The voltage is ok,it's curious that if I put another lpc in the bot, it works fine. When I insert the other one, it executes the last program and gets very hot.

Re: Lpc1769 really hot

lpcware — Wed, 15 Jun 2016 23:33:27 GMT

Content originally posted in LPCWare by frame on Tue Oct 30 08:18:59 MST 2012
[I][B]The voltage is ok,it's curious that if I put another lpc in the bot, it works fine.
[/B][/I]
That is an indication, but no proof. Current consumption can vary for individual IC's,
as well as with temperature and age.

[I][B]While testing the lpc in my system (a sumo bot) a led started blinking ...
[/B][/I]
This suggests motor drives. Do you supply this from USB ?
If so, I would switch to a separate power supply. You might get strange effects if the current consumption
exceeds the capability of the USB port somewhere during runtime.

As further step,I would disconnect the external periphery one by one, and measure the current consumption then.
And I would run the application in the debugger, to see what the controller is up to while he pulls that much current.
Or include debug output to narrow down the issue.

Re: Lpc1769 really hot

lpcware — Wed, 15 Jun 2016 23:33:28 GMT

Content originally posted in LPCWare by vasanth on Tue Oct 30 09:15:00 MST 2012

Quote: DjCracks
it executes the last program and gets very hot.

Are you sure it is executing? Dead chips have a bad tendency to get hot. :eek:
Check the Supply and Ground pins for a physical short. Replace the LPC if it is the case. :)

Re: Lpc1769 really hot

lpcware — Wed, 15 Jun 2016 23:33:28 GMT

Content originally posted in LPCWare by DjCracks on Tue Oct 30 18:31:51 MST 2012
I've checked and Supply and Ground pins are in short, my LPC is dead. What could have caused this? I've been testing the bot for four hours when it occured. Adding a TR5 subminiature fuse would protect the LPC? If so, does anyone know its max current draw?
Thanks.

Re: Lpc1769 really hot

lpcware — Wed, 15 Jun 2016 23:33:29 GMT

Content originally posted in LPCWare by serge on Fri Nov 02 05:48:42 MST 2012
What is your LPC driving and more importantly how is he doing that? What does your interface circuitry looks like?

It looks like your LPC has to provide too much power to the connected parts.