Thanks! I just ordered some. I'll let you know if it works!
I think it will go poorly. Something like the MCP112 is designed for a rapidly increasing power supply that will stay well above the trigger point once it has passed.
Your slowly increasing solar supply will come out of reset, start draining the capacitor, and then assert the reset again ... not really what you want. You have several things you need to do:
- Hold the part in reset when the voltage is too low to safely operate (MCP112 can do this one function)
- Go to sleep when the voltage gets low (usually that function is built into a properly selected micro)
- Start operation at a given voltage (comparator)
You may be able to use the MCP112 to get the part started .. maybe, if the first thing that happens if you put the micro to sleep until it gets an interrupt on a pin that indicates the voltage is high enough, which you can do with a low power comparator or another power supervisor. Then you use a brown-out detect built into the micro to shut it down as appropriate.