Timeline for Astable 555 timer circuit that resets on a heartbeat
Current License: CC BY-SA 4.0
13 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Jan 18, 2019 at 4:52 | vote | accept | Max | ||
| Dec 21, 2018 at 21:11 | comment | added | Synchrondyne | @Transistor - an aside, but generally I prefer external watchdogs to internal ones. Too easy for misbehaving code to accidentally vector to a routine that disables the watchdog. An external watchdog (preferably a window watchdog) that can't be disabled by the processor is much more robust. | |
| Dec 21, 2018 at 20:26 | comment | added | Jasen Слава Україні | NE555DR won't work on 3.3V use TLC555C or 7555 etc instead. | |
| Dec 21, 2018 at 19:25 | review | Close votes | |||
| Jan 5, 2019 at 3:05 | |||||
| Dec 21, 2018 at 19:07 | comment | added | Chris Stratton | I'm voting to close this question as off-topic because "it doesn't seem to work" is not a valid problem description. Questions are required to be specific about the difference between expected behavior and observed behavior. What debugging steps have been taken? Either monitor the input and output with a scope, or if the time is human scale add an LED to each, being careful to do so in a way which does not disrupt the operation of the circuit (ie, possible after a buffer amp). | |
| Dec 21, 2018 at 18:47 | comment | added | Tony Stewart EE since 1975 | Not without part numbers. I guess you aren't using real-time IRQ's which makes this task easier. You need a plastic cap for timing 60 s. | |
| Dec 21, 2018 at 18:21 | answer | added | Kevin Brant | timeline score: 3 | |
| Dec 21, 2018 at 18:18 | comment | added | Max | @TonyEErocketscientist I can possibly reduce the time interval to 30seconds, its just that I don't want to bulk up the code with sending a pulse every 30 seconds. But the problem now is the circuit doesn't even work, is there anything you could recommend to fix it? | |
| Dec 21, 2018 at 18:17 | comment | added | Max | @Transistor I not sure for the reason of the crash/hang but this is what i received from the client. | |
| Dec 21, 2018 at 18:10 | comment | added | Tony Stewart EE since 1975 | 1 minute is expecting a lot for an analog RC decay time due to limited choice to plastic caps for low leakage current much less than pull up current or equiv R. Very Poor design to copy. You want an edge sensitive retriggerable port that will never go into fibrillation or repetitive false triggers. So choose a better spec or design to copy. | |
| Dec 21, 2018 at 14:38 | comment | added | crj11 | google.com/search?q=watchdog+timer+chip | |
| Dec 21, 2018 at 14:30 | comment | added | Transistor | (1) Does the ESP8266 not have an internal watchdog timer? (2) Why does it crash/hang? Bad code? | |
| Dec 21, 2018 at 14:06 | history | asked | Max | CC BY-SA 4.0 |