Serial Port
The ICSP programming port doubles as the serial port. Most of the time you won't even need to think about the programming port so just treat it as a serial port. This is a TTL level port so you will need to use a serial-TTL to USB converter to connect it to your PC. Some possible converters can be found on e-bay or SparkFun:-
http://shop.ebay.com/i.html?_kw=usb%20t ... pos=&gbr=1
(drivers for above converter found here:
http://www.silabs.com/products/mcu/page ... ivers.aspx )
http://www.sparkfun.com/commerce/produc ... ts_id=9115
http://store.diydrones.com/product_p/ttl-232r-3v3.htm
If you already have a USB converter from Intelligent Flight or some of the other manufacturers (RVOSD, Flytron, etc.) those will also work. You will need to make sure that the pin-outs of the connectors match up with that of the OSD header.
Some functions can only be set via the serial port - including the setting of the callsign to be displayed and the downloading of flight logs. The firmware can also be updated via the same serial port so new special programmer is required to update the firmware (although if something should go wrong - you may need a programmer to fix it).
I highly recommend using TeraTerm Pro, a free terminal software, downloadable here:-
http://en.sourceforge.jp/projects/ttssh2/releases/
The serial port settings are 38400, 8N1.
(The baudrate has been changed to 115200 from version 7.5Beta11 and upwards.) You will know that things are working if you see a copyright message show up on the terminal once the DragonOSD+ is powered up. If you don't see that, some basic things to check are:-
0. Is the USB converter correctly installed and recognized as a COM port?
1. Is the correct COM port being selected?
2. Make sure no other terminal program (HyperTerm or TeraTerm is running when updating)
3. Are the serial settings correct? (38400 baud, 8N1)
4. Are the RX and TX lines reversed or crossed?
5. Is the serial port being connected to the correct header pins?
6. Is the OSD powered up?
Note that the serial connection consists of 3-wires connected to the ICSP port. The three wires are marked out in the photos above. Do not connect anything to the remaining two pins.
Daniel