I would urgently recommend the use of a reset controller with brown-out detection (BOD) instead of RC-reset circuit, and some sort of protection circuitry, which turns-off the LEDs when the micro runs ill, like it's shown in the following snippet, which I already published in an earlier thread:




A CD4538 monoflop is used to provide a protection against excessive overload conditions of LEDs: Monoflop is strobed by the same port pin that also strobes the watchdog of MAX1232. Strobing pulses retrigger the monoflop all the time, so that '/Q' output of CD4538 is permanently emitting 0V. This signal is used to enable the 74HC138.
If, for any reason, strobe pulses disappear, monoflop is no longer triggered, '/Q' output of CD4538 goes high and all the LED drivers are disabled.
10msec was chosen for the monoflop pulse period and monoflop should be strobed every 7msec. Without the monoflop the LEDs are permanently driven with the huge mulitplexing current if the micro runs ill and the LEDs get fried.

Further protection is provided by feeding the 'reset' signal to another enable input of 74HC138: Whenever the micro is resetted (power-on, brown-out situation, etc.) LED drivers again are disabled.

Kai