I see, I forgot that NanodeRF uses a bootloader. The program you are trying to compile is version 1.8.3, which uses close to all the 32KB flash memory. As a result it can’t allow a bootloader (which takes 512B in the case of NanodeRF I think). Since OpenSprinkler 1.2, the board has included a built-in USBtinyISP (or USBasp) programmer, and hence the microcontroller does not use a bootloader anymore, freeing up some space.
There are two work-arounds you can use:
1. try to reduce the code size by commenting out features that you don’t need, such as the part corresponding to manual operation mode. You really only need to free up a few hundred bytes of flash memory space to make it fit.
2. alternatively, if you have an ISP programmer (such as USBtinyISP, USBasp, or use Arduino as ISP), you can use that to directly program the chip. Note that this will overwrite the bootloader, but if you need you can always put the bootloader back by using the ‘Burn Bootloader’ option in the Arduino IDE.