Jee Labs Talk

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1. pedro
   

   In the JeeNode v3 I recently received I see that the SUTCKSEL fuse is set to Ext. Crystal osc. 8MHz. If I look at the ceramic resonator in place it is a 15MHz one. Is this the correct setting for a 15MHz resonator?

   Posted 11/11/2009 20:34:48

2. jcw
   

   The JeeNode and JeeNode USB use a 16 MHz resonator. The new JeeLink uases a 16 MHz crystal. I'm often con-fuse-d about the fuse settings, so it may well be that I messed things up.

   I'm using these settings with avrdude: -U efuse:w:0x05:m -U hfuse:w:0xDA:m -U lfuse:w:0xFF:m

   Did I mess up? Or mix up 168 vs. 328?

   Posted 12/11/2009 21:31:30

3. pedro
   

   I don't use avrdude... my current fuse values are:
   extended = 0xF9
   high = 0xDD
   low = 0xFF

   I'm not using the boot loader and I have the crystal as a 8MHz external...
   It looks like working but when I do a delayms(10000) I don't have 10 seconds, I have less then that...

   And the ressonater that's soldered to my JeeNode has 15.00 MHz marked, not 16...

   Posted 13/11/2009 23:02:45

4. jcw
   

   I just checked, the fuses are set the same as with the Arduino 0017 IDE:
   [code]
   atmega328.name=Arduino Duemilanove or Nano w/ ATmega328

   atmega328.upload.protocol=stk500
   atmega328.upload.maximumsize=30720
   atmega328.upload.speed=57600

   atmega328.bootloader.lowfuses=0xFF
   atmega328.bootloader.highfuses=0xDA
   atmega328.bootloader.extendedfuses=0x05
   atmega328.bootloader.path=atmega
   atmega328.bootloader.file=ATmegaBOOT168atmega328.hex
   atmega328.bootloader.unlockbits=0x3F
   atmega328.bootloader.lockbits=0x0F

   atmega328.build.mcu=atmega328p
   atmega328.build.fcpu=16000000L
   atmega328.build.core=arduino
   [/code]
   That's: Ext crystal >= 8 MHz, boot reset vector, 1 Kword boot section, ISP enable, 2.7V brown-out.

   Your values can be different since you don't use the Arduino bootloader.

   I really can't explain the 15 MHz. Weird - I only have 16 MHz resonators here, and always ordered the same one. I'll be happy to send you another one if you want. You should be able to determine the value by timing the delay you get, assuming you compiled your code with FCPU set to a known value.

   Posted 14/11/2009 11:28:51

5. pedro
   

   I'm using AVR Studio 4 plugged to a STK500 for programing. The fuse configuration is a combo box and it is misspelled, in fact the configuration you use is >= 8MHz crystal and not = 8MHz crystal, so it is ok.
   For the other fuses they are different because I'm not using the boot loader, I'm compiling the program in AVR Studio 4 and I'm using the STK500 from Atmel connected to my PC serial port to program the micro-controller directly.

   One of the advantages of the STK500 is that I can just use its ISP connector to program the micro-controller directly in the JeeNode or if I mess things up (as it happened one while testing the crystal fuses, I chose the external clock and the micro-controller was dead) I plug the microcontroller directly to the STK500, configure its power supply, configure a clock source and program it again.

   Posted 16/11/2009 09:35:08