I’ve been poking around with a Lilypad Arduino board, with an interest in wearable technology.

I wanted a way for the device to talk to other devices, so I scored a BlueSMiRF Gold Bluetooth modem. Getting it connected to the Lilypad, however, was less than obvious to me.

The problem is that there have been different versions of both the Lilypad and the BlueSMiRF, and wiring instructions either refer to an older version of one or the other, or they refer to connections on the assumption that you know exactly where to find them.

What I could not find was a simple diagram that labled all of the pins and connections on the current Lilypad.

The best I found was in this excerpt from Programming Interactivity. It does not, however, label the header pins. (Also they show two different versions of the Lilypad. The 4-pin header is the older version.)

Yes, I looked at the schematic. However, until I dig out those EE textbooks I will not be able to read the pin labeling with any confidence.

After much Googling and experimenting, though, I did figure out (I’m pretty sure) the correct pin labeling. I was able to then hook up the BlueSMiRF to the Lilypad, kick off the Android Amarino app on my G1, and pair up the devices.

Here’s the pin labeling I came up with (with the Lilypad rotated so that the head pins are at 9 o’clock)

             --------
            |
       -------- RTS
       -------- TX-O    
       -------- RX-I    
       -------- 3.3V    
       -------- GND     
       -------- GND
            |
             --------

I’ve also written some posts about this on the Arduino forums here

BTW, if you think I’ve gotten something wrong here, please drop me some E-mail.