serial connections

[time2dive]

I know that the Prop2 can do serial communication via the pins. What do the the red, black and white wires actually hook up to.  I have an audio board that has 5vdc, gnd, tx and rx.  In theory the Prop2 should be able to talk to the audio board if I knew where to hook up the wires.

[Jeff Haas]

Here are a couple of pictures that show how to connect things.  You use the W/R/B headers to connect to external boards like this. 

Red = VCC or 5V
Black = Ground or GND
White = Signal from Prop-2, goes to RX on the MP3 board

These connections will give power to the MP3 board and send signals to it.  In the first picture I'm plugged into the header for P7.  There is also a TX pin on most MP3 boards, this is used for sending busy signals back to the microcontroller.  I don't bother with this, I just time my program so I know how long the MP3 will run.

I made a small adapter board for the Tenda audio board, because it doesn't have a headphone jack built in.  It's on the right.  I used two headers to plug into for stability.  The second picture shows a closeup of the adapter with the Tenda MP3 board unplugged.  These connections match what's on the docs for the board - VCC and GND are pins 20 and 19, and RX is pin 16.  You can just make out the white and yellow wires going to the headphone jack, those are the left and right audio channels.

You don't have to connect this way, you could go directly to the pins, but this is easier for me to unplug the Tenda board and pull out the SD card on it when I change the MP3s.