We’d like to use a Xenon like a HW watchdog to reset an Argon by taking the Argon’s reset pin low. However, we just can’t make it work.
In a nutshell, the Argon is creating a heartbeat by toggling D7 high/low every half second. The Xenon watches this thru an input pin, and if the Argon’s pin state doesn’t toggle for a certain period of time, the Xenon takes the Argon’s reset pin low for 1 second. However, the Argon doesn’t reset.
But if we use the same code to reset a Xenon, it works every time. Also, if the Argon’s reset pin is connected directly to ground, it does reset.
Any thoughts on why the Xenon can be reset by taking its reset pin low by another controller, but the Argon can’t?
Update: I added a 470 ohm pulldown from the Argon’s reset pin to ground, and now when the other controller takes the Argon’s reset pin low, it resets. Why doesn’t the Xenon need this? Or a better question is why does the Argon need this?