Hey guys,
I've picked up a Seeedstudio Rainbowduino and I need to upload a sketch to it's onboard AtMega168. From what I've been reading you can gerryrig another Arduino to pass through a TTL stream.
When I wire it up, RX/TX/DTR/GND/VCC and hit upload on my Seeeduino the Rainbow obviously registeres something as it resets but the Arduino IDE ends up throwing an error.
Has anyone tried this? Can you give me any tips?
-Miles
i assume u have removed the chip from the host arduino and made sure u got the rx and tx the right ways round? 
also i have found i have to manually reset a board b4 it will take a sketch even tho the ide reset it just b4.. not sure wats going on there prolly just my hardware or my crap old laptop i was using..
alternatively u can make a simple rs232 to ttl converter (if u have a serial port on the pc), but the method u are trying should work..
double check your connections and settings 
Ah, the MCU within teh Seeeduino is SMD. I could use my Freeduino with removable chip. Any ideas where the DTR pin is?
Ah that worked great ;)...
Should have put 2+2 together
glad u got it working
(DTR = reset 
)