Thanks very much for the info about the voltage divider and the diode on the reset line.

I've included the instructions for that reset line and its accompanying voltage divider and diode in my README.txt. I haven't implemented it yet, but when I get the new Betz board in later this week, if it's needed on the new Betz board I will implement it then. If I don't seem to need it on the new Betz board (I didn't need it on the last one as long as I was powering it off the Pololu), then I will run things for a while without it. I'll make sure that the digital inputs are running stably and last a little while for me without the reset line, then I'll try implementing it and see if my chip blows again. If it runs stably with the new reset line configuration, I'll include it in my final PCB design.

By the way, if you look at my latest code, the Reset line code is now implemented as a separate function, but the code is temporarily disabled behind a boolean flag at the top of the code: "performResetLinePhysical". To use it yourself you'll need to flip that flag to true.

I have another question about my schematic that you might be able to help me with.

I'm using the attached schematic from this page for my MAX232 circuit. It's wired as follows:

MAX232 Pin 1 and 3 aka C1+/C1- - Bridge with a 2.2uf ceramic capacitor
MAX232 Pin 4 and 5 aka C2+/C2- - Bridge with a 2.2uf ceramic capacitor
MAX232 Pin 2 aka V+ - Connect to Pololu 5v via a 2.2uf ceramic capacitor
MAX232 Pin 6 aka V- - Connect to GND via a 2.2uf ceramic capacitor
MAX232 Pin 11 aka TTL-I1 - Connect to Arduino Mega Board 18 aka Tx1
MAX232 Pin 12 aka TTL-O1 - Connect to Arduino Mega Board 19 axa Rx1
MAX232 Pin 13 aka 232-I1 - Connect to RS-232 plug pin 3 aka Tx
MAX232 Pin 14 aka 232-O1 - Connect to RS-232 plug pin 2 axa Rx
MAX232 Pin 15 aka GND - Connect directly to GND
MAX232 Pin 16 aka VCC - Connect directly to Pololu 5v

I'm using 2.2uf capacitors for all of this because of a note in the datasheet. I'm using this MAX232 chip from Digikey, and when I look at the datasheet for the chip, I see the following note:



So that's why I'm using 2.2uf ceramic caps.

So far so good. My question is about the last capacitor "C5" in the attached schematic. It simply bridges 5v and Gnd with a capacitor. (I'm just using another 2.2uf ceramic capacitor there.) I'm wondering (a) why is this cap there in the schematic at all, and (b) if that is having an adverse affect on my board/circuit since it's bridging the 5v rail that everything else is running off of. Any ideas or recommendations related to that capacitor?

Thanks!