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11 years, 1 month ago.
Is a watchdog-reset different to a hardware-reset?
Hi all!
I've connected a RFM22 http://mbed.org/users/charly/notebook/rfm22/ module to my mbed to receive and display messages sent from another mbed. Works, but after some time (hours) the receiver stops and doesn't display new messages. Until I find the reason for the problem I added a watchdog to reset the mbed and start over again, if it doesn't receive a message within 5 minutes.
Now I observe following strange behavior:
When I do a hard-reset with the reset-button of the mbed it receives for minimum an hour or two without triggering the watchdog.
After the watchdog fires the first time, only some 3 to 10 messages are received and then it stops again. And so on: WD-Reset, max. 10 messages, WD-Reset, max. 10 Messages,....
It seems that the watchdog-reset does something different than the hard-reset. Is this true? What do I have to do to initialize everything like after a hard-reset?
I use this Watchdog-Library: http://mbed.org/users/WiredHome/code/Watchdog/
Here is a part of the log:
log
.... got message:13.03.2013 21:39 >Nr:33220: 10.8 11.3 23.9 22.6< got message:13.03.2013 21:39 >Nr:33221: 10.8 11.3 23.9 22.6< got message:13.03.2013 21:39 >Nr:33222: 10.8 11.3 23.9 22.7< got message:13.03.2013 21:40 >Nr:33225: 10.8 11.3 23.9 22.6< got message:13.03.2013 21:40 >Nr:33226: 10.9 11.3 23.9 22.6< got message:13.03.2013 21:40 >Nr:33227: 10.9 11.4 23.9 22.6< got message:13.03.2013 21:41 >Nr:33228: 10.9 11.4 23.9 22.6< got message:13.03.2013 21:41 >Nr:33229: 10.9 11.4 23.9 22.6< got message:13.03.2013 21:41 >Nr:33230: 10.9 11.4 23.9 22.6< got message:13.03.2013 21:41 >Nr:33231: 10.9 11.4 23.9 22.6< got message:13.03.2013 21:41 >Nr:33232: 10.9 11.4 23.9 22.6< got message:13.03.2013 21:41 >Nr:33233: 10.9 11.4 23.9 22.6< got message:13.03.2013 21:42 >Nr:33234: 10.9 11.4 23.9 22.6< got message:13.03.2013 21:42 >Nr:33235: 10.9 11.4 23.9 22.6< got message:13.03.2013 21:42 >Nr:33236: 11.0 11.4 23.9 22.6< got message:13.03.2013 21:42 >Nr:33237: 11.0 11.4 23.9 22.6< got message:13.03.2013 21:42 >Nr:33238: 11.0 11.4 23.9 22.6< got message:13.03.2013 21:43 >Nr:33239: 11.0 11.4 23.9 22.6< got message:13.03.2013 21:43 >Nr:33240: 11.0 11.4 23.9 22.6< got message:13.03.2013 21:43 >Nr:33241: 11.1 11.4 23.9 22.6< got message:13.03.2013 21:43 >Nr:33242: 11.1 11.4 23.9 22.6< got message:13.03.2013 21:43 >Nr:33243: 11.1 11.4 23.9 22.6< got message:13.03.2013 21:43 >Nr:33244: 11.1 11.5 23.9 22.6< got message:13.03.2013 21:44 >Nr:33245: 11.1 11.5 23.8 22.6< got message:13.03.2013 21:44 >Nr:33246: 11.1 11.5 23.8 22.6< got message:13.03.2013 21:44 >Nr:33247: 11.1 11.5 23.8 22.6< got message:13.03.2013 21:44 >Nr:33248: 11.1 11.5 23.8 22.6< got message:13.03.2013 21:44 >Nr:33249: 11.1 11.5 23.8 22.6< got message:13.03.2013 21:45 >Nr:33250: 11.1 11.6 23.8 22.6< got message:13.03.2013 21:45 >Nr:33251: 11.1 11.5 23.8 22.6< got message:13.03.2013 21:45 >Nr:33252: 11.1 11.6 23.8 22.5< got message:13.03.2013 21:45 >Nr:33253: 11.1 11.6 23.8 22.5< got message:13.03.2013 21:45 >Nr:33254: 11.2 11.6 23.8 22.5< got message:13.03.2013 21:45 >Nr:33255: 11.2 11.6 23.8 22.5< got message:13.03.2013 21:46 >Nr:33256: 11.2 11.6 23.8 22.5< got message:13.03.2013 21:46 >Nr:33257: 11.2 11.6 23.8 22.5< got message:13.03.2013 21:46 >Nr:33258: 11.2 11.6 23.8 22.5< got message:13.03.2013 21:46 >Nr:33259: 11.2 11.6 23.8 22.5< Connected to mbed RF22-Receive-V3.2 I am receiving with address 2 ... got message:13.03.2013 22:03 >Nr:33350: 11.9 12.4 23.4 22.2< got message:13.03.2013 22:03 >Nr:33351: 12.0 12.4 23.4 22.2< got message:13.03.2013 22:03 >Nr:33352: 12.0 12.4 23.4 22.2< got message:13.03.2013 22:03 >Nr:33353: 12.0 12.4 23.4 22.2< got message:13.03.2013 22:03 >Nr:33354: 12.0 12.4 23.4 22.2< got message:13.03.2013 22:04 >Nr:33355: 12.0 12.4 23.4 22.2< got message:13.03.2013 22:04 >Nr:33356: 12.0 12.4 23.4 22.1< got message:13.03.2013 22:04 >Nr:33357: 12.0 12.4 23.4 22.2< got message:13.03.2013 22:04 >Nr:33358: 12.1 12.4 23.4 22.2< got message:13.03.2013 22:04 >Nr:33359: 12.1 12.4 23.4 22.2< got message:13.03.2013 22:04 >Nr:33360: 12.1 12.4 23.4 22.1< got message:13.03.2013 22:05 >Nr:33361: 12.1 12.5 23.4 22.2< got message:13.03.2013 22:05 >Nr:33362: 12.1 12.5 23.4 22.2< Connected to mbed RF22-Receive-V3.2 Watchdog caused reset. I am receiving with address 2 ... got message:13.03.2013 22:10 >Nr:33391: 12.2 12.7 23.2 22.1< got message:13.03.2013 22:10 >Nr:33392: 12.2 12.8 23.2 22.1< got message:13.03.2013 22:10 >Nr:33393: 12.2 12.8 23.2 22.1< got message:13.03.2013 22:11 >Nr:33394: 12.2 12.8 23.2 22.1< Connected to mbed RF22-Receive-V3.2 Watchdog caused reset. I am receiving with address 2 ... got message:13.03.2013 22:16 >Nr:33423: 12.4 13.0 23.2 22.0< got message:13.03.2013 22:16 >Nr:33424: 12.4 13.0 23.2 21.9< got message:13.03.2013 22:16 >Nr:33425: 12.4 13.0 23.2 21.9< got message:13.03.2013 22:16 >Nr:33426: 12.4 13.0 23.1 22.0< Connected to mbed RF22-Receive-V3.2 Watchdog caused reset. I am receiving with address 2 ... got message:13.03.2013 22:22 >Nr:33455: 12.6 13.2 23.1 21.9< got message:13.03.2013 22:22 >Nr:33456: 12.6 13.2 23.1 21.9< got message:13.03.2013 22:22 >Nr:33457: 12.6 13.2 23.1 21.9< got message:13.03.2013 22:22 >Nr:33458: 12.6 13.2 23.1 21.9< Connected to mbed RF22-Receive-V3.2 Watchdog caused reset. I am receiving with address 2 ... got message:13.03.2013 22:27 >Nr:33487: 12.8 13.4 22.9 21.8< got message:13.03.2013 22:28 >Nr:33488: 12.8 13.4 22.9 21.8< got message:13.03.2013 22:28 >Nr:33489: 12.8 13.4 22.9 21.8< got message:13.03.2013 22:28 >Nr:33490: 12.8 13.5 22.9 21.8<
2 Answers
11 years, 1 month ago.
Watchdog resets only the target chip (e.g. LPC1768), while the reset button resets also the mbed interface chip and causes it to rescan the flash drive for new images. If you call mbed_reset() on WDT timeout, it might work better.
Hi Igor! I tried adding a mbed_reset() to the watchdog-reset, but then it resets forever as soon as the watchdog fires the first time!
code-snipet
...
if (wd.WatchdogCausedReset()) {
pc.printf("Watchdog caused reset.\r\n");
lcd.setLine(1,"Watchdog fired!");
mbed_reset();
}
wd.Configure(5*60); // sets the watchdog timeout interval in seconds
...
It seems that I have to manually delete a register after the watchdog-reset. I have to search the documentation....
Charly
posted by 16 Mar 2013Yes, you must clear the flag manually. From the UM:
Quote:
The Watchdog time-out flag (WDTOF) can be examined to determine if the Watchdog has caused the reset condition. The WDTOF flag must be cleared by software.
The following should be enough:
// clear WDTOF flag (bit 2) LPC_WDT->WDMOD &= ~(1<<2);
11 years, 1 month ago.
Karl,
I've noted a difference. If you but in a new binary file, a mbed reset (hardware or software) will load the new image whereas the Watchdog timeout will not.
...kevin