I have the following setup: Arduino UNO without the chip: Arduino UNO Notice that the Atmel chip is missing.

And i have a Baby Orangutan: Orangutan

The orangutan burned with Arduino Uno R3 Bootloader.

I connected Orangutans PD0 (RX) and PD1 (TX) to the Uno's D0 (RX) and D1 (TX) so that i can program the orangutan using Arduino AVR programmer.

When I'm connecting my Uno to the PC using a USB Cable, it's being recognized as a Uno R3 even when the chip is off, becuase the Orangutan has a Uno bootloader.

Now the problem is when I'm trying to upload a sketch it sais:

avrdude: stk500_getsync(): not in sync: resp=0x00


The following pins are connected:

> Uno      -->   Orangutan  
> D1 (TX)  -->   PD1 (TX)  
> D0 (RX)  -->   PD0 (RX)  
> 5V       -->   VIN  
> GND      -->   GND  
> RST      -->   PC6 (RST) 

Following: Baby Orangutan B Pin Mappings.

  • 1
    \$\begingroup\$ The PC's identification of the board is based on the USB serial chip, not on the bootloader. So you have not yet proven connectivity to the bootloader. This is likely either a mistmatch between the bootloader's baud rate and that set in the arduino GUI, or else a problem resetting the target, or else TX/RX interchanged. \$\endgroup\$ Commented Dec 7, 2012 at 15:52

1 Answer 1


From your description and the first photograph, your Uno and Orangutan do not have their Ground lines connected. This could be an oversight in your description, but if not, two circuits need to have a common reference for this kind of programming link to work. Wire the GND pins of the two boards together if you haven't already.

To program boards similar to the Baby Orangutan, here are the connections I use from my Uno with the MCU removed:

> Uno    -->   Other  
> TX     -->   TX  (*note)  
> RX     -->   RX  (*note)  
> 5V     -->   Vcc  
> GND    -->   GND  
> RST    -->   RST  

*note: On at least one board, the TX and RX lines needed to be reversed.

  • \$\begingroup\$ I connected my Orangutan the the Uno's 5V and GND, so now it has common ground lines (fix me if I'm worng), connected arduino RST to Orangutan RST, and by reversed TX RX you mean: TX -> RX, RX -> TX ? I tried both configurations but still not in sync while uploading.. \$\endgroup\$
    – Danpe
    Commented Dec 7, 2012 at 15:44
  • \$\begingroup\$ @Danpe Yes, reversing TX/RX means precisely that. Now, if that too didn't work, you may have to fiddle with the reset line on the Uno. There are discussions on arduino.cc about wiring a capacitor (various opinions on how many microfarads) between the RST pin and GND, another group suggests a resistor between RST and Vcc. It would behoove you to look up those discussions, it'll be trial and error, a bit. \$\endgroup\$ Commented Dec 7, 2012 at 15:54
  • \$\begingroup\$ Another experiment worth trying is to hit the board's reset button (if it has one) just after you click on the Arduino UI to upload a sketch. If not, try pressing the Uno's reset button instead. \$\endgroup\$ Commented Dec 7, 2012 at 15:56

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.