@Yveaux Thanks for your response. I guess that's it. I have to burn a bootloader first :-). I have a USBasp Programmer for that. Can you point me to a wiring diagram that shows how to connect the programmer to the circuit board?

Hi Guys,

I also bought two of these boards a while ago. I have the NRF, a BH1750 sensor, and cables for battery and solar panel soldered to the board. I'm now trying to upload the sample code to the board. I have the board connected to my Mac as usual through an FTDI adapter. I'm running Arduino 1.8.6. The code compiles fine but cannot upload to the board. The following error is produced:

"Sketch uses 4266 bytes (13%) of program storage space. Maximum is 30720 bytes.
Global variables use 312 bytes (15%) of dynamic memory, leaving 1736 bytes for local variables. Maximum is 2048 bytes.
avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 1 of 10: not in sync: resp=0x00
avrdude: stk500_recv(): programmer is not responding"

I guess the board does not get in flash mode... Settings I use in Arduino are:

Board: Arduino Pro of Pro Mini
Processor: "ATMega328 P (3,3V, 8 MHz)

Any ideas what is going wrong? I would love to see some examples of how the board is used. I want to use it to drive a relay that turns on my DMX controlled lights in my shed. Adding a temp/humidity, motion, and perhaps smoke sensor would be nice too.

Hope you can help me move forward. Cheers, Roland.