The code comes as .pde as it uses a lot of the arduino wiring for servo controlling.
In the .zip file you will also find a .hex file that you can upload to your solarroboflower directly over the FTDI connector or the programmig pins on the mainboard using a AVR programmer of your choice.
You can modify the code using the arduino environment and upload it directly form there.
Please specify Arduino Mega 3.3V @ 8 Mhz as your targetboard.
The SolarRoboFlower runs at 5V but the bootloader vom the Arduino Mega 3.3V also uses the internal clock @ 8 Mhz and is therefor compatible with your robot.
sudo avrdude -P /dev/ttyUSB0 -b 19200 -c avrisp -p m168 -v -e -u -U lock:w:0x3f:m -U lfuse:w:0xE2:m -U hfuse:w:0xDD:m -U efuse:w:0x00:m; # setting fuses to use internal clock @ 8Mhz sudo avrdude -P /dev/ttyUSB0 -b 19200 -c avrisp -p m168 -U flash:w:ATmegaBOOT_168_pro_8MHz.hex; #flashing the arduino bootloader sudo avrdude -P /dev/ttyUSB0 -b 19200 -c avrisp -p m168 -D -U flash:w:firmware.hex #write firmware