RFBee has no processor crystal?

I just got some RFBees, and I notice that there are pads for a crystal/resonator for the ATMega168 but there’s no part soldered there. Is that intentional? I could not find a schematic diagram or parts list to verify.

If the chip is using the internal oscillator, how can the serial port work reliably through the whole temperature range?


Hi Bob,

We leave the crystal unsolder intentionally, and use the atmega168 internal crystal.
There is a mistake of the RFBee mannual. The temperature in which atmega168 and cc1101 can normally work should be -40°C to 80°C. However we didn’t test the serial port working in different temperature.

If (as I was) you’re dumb enough to burn the wrong bootloader to the RFbee, you’re going to have to do something silly like this to get the fuses set back to their correct settings. BEWARE! I found that “Lillypad” works, while “Arduino Pro” will brick the RFbee.

Hi Andy,

Yes, if you burn the wrong bootloaders, an crystal must be solder on the pad.

“LilyPadBOOT_168.hex” and “ATmegaBOOT_168_pro_8MHz.hex” should be ok, which use the internal 8MHz as the CPU clock.

And the fuse configuration should be as follows:

Low Byte: 0xd2 High Byte: 0xdd Extended Byte: 0xf8 Lock Byte: 0xcf