wanchope
Member level 4
picaxe
Hi,
I found one of my microcontroller systems hang from time to time. When it hangs, I need to remove the battery and wait for 20 seconds for the capacitor to drain. After that, I connect back the battery and the system will work again.
I would like to design a hardware watchdog with this 20 seconds delay. When the system is running, the mcu will give a heartbeat pulse every 1 second. If the pulse is not detected by this watchdog timer, it will pull high the gate of a Pmos and wait for 20 seconds before pulling down the gate pin.
Any suggestion to go about this?
Hi,
I found one of my microcontroller systems hang from time to time. When it hangs, I need to remove the battery and wait for 20 seconds for the capacitor to drain. After that, I connect back the battery and the system will work again.
I would like to design a hardware watchdog with this 20 seconds delay. When the system is running, the mcu will give a heartbeat pulse every 1 second. If the pulse is not detected by this watchdog timer, it will pull high the gate of a Pmos and wait for 20 seconds before pulling down the gate pin.
Any suggestion to go about this?