I use my old Palm IIIc as a Serial Console for my OpenWRT router. Palm use, like my Asus WL500G Premium OpenWRT router, TTL serial levels inside the box. I opened my Palm and on the “LA CUCARACHA NEGRA” PCB you’ll see the MAX 3386e IC, which convert’s the TTL signal to (more or less) rs232 serial signal level.

MAX3386 schematics
Now just connect the TTL signal level from the Openwrt router to the MAX 3386e input pin’s and you’re done:

LA CUCARACHA NEGRA PCB
Craddle RX pin 3:
output (rs232) MAX 3386e pin 13, input (TTL) MAX 3386e pin 10 <- connect here
Craddle TX pin 5:
output (rs232) MAX 3386e pin 17, input (TTL) MAX 3386e pin 17 <- connect here
The pins you had to connect to your OpenWRT router are marked in the pic above (ttl rx and ttl tx).
The final result look like this:

I use Pocketterm as Terminal editor, other terminal editor tools crash from time to time, I assume this is because of the missing connections (CTS / DTR), even with disabled flow control.
Comments, question -> michu at neophob dot com

3 Comments
1 stam wrote:
Hello there!
Congratulation for your amazing site!!!
Just one quick question if you have an answer in mind!
I have an old Palm V lying here doing nothing, is there any way of connecting it to a router (or to an arduino) without opening it to solder anything inside?
I was thinking ruining the craddle instead of the palm!
Thanks again,
stam
2 michu wrote:
hey stam
I’m afraid you need to open your device, as the serial craddle uses +12V/-12V (serial level) and you want ttl level…
3 stam wrote:
Thank for the reply!
I see you point…
I was thinking of using something like a Max232 that converts from RS-232 to TTL.
So the whole project would be like this:
Palm V —> Cradle —> Max232 —> Router
Have a nice day!