hi
over the past couple of years I have built quite a few bb arduino running at 8Mhz. in the past, to upload sketches I put the 8Mhz cpu on arduino in place of the original processor, selected the arduino board as breadboard running at 8Mhz and uploaded sketches with no problem, the always worked as expected when fitted on the bb.
I have downloaded and installed the latest arduino software (1.66) and the bb 1.6 hardware definition file into my 'hardware' directory in the sketches folder.
Now I have two problems, when I select bb running at 8Mhz in the boards menu I get an error which says 'Board breadboard:avr:atmega328bb doesn't define a 'build.board' preference. Auto-set to: AVR_ATMEGA328BB'. And I can no longer upload a sketch to the 8Mhz chip when I mount it on the arduino board.
Has anyone else had a similar problem, and should I be able to upload sketches to the 8Mhz chip in this manner or have I just been lucky in the past.
I would expect sketches to upload this way as fuses are set for 8Mhz so crystal osc is disabled and the arduino software knows its 8Mhz by board selection
Thanks in advance for any help, this problem is easy to get around but at the same time is interesting
Dave
After several hours investigating this problem it apears i just have a rogue chip!!!!
I tried a new chip with new 8Mhz bootloader and everything works just as it always has.
putting the 'duff' chip on stk500 and using Atmel studio fuses read E2,DA,FF as they should, lockbits read FF as i set them and signature is 1E,95,0F as it should be. I bought 10 of the chips from Ebay, cheap (chinese) so maybe this is a warning not to buy cheap chips (cheap as chips ??) from questionable sources.
I hope my lesson will maybe stop someone else doing the same thing, my 'cheap' chips cost me hours of my time so they turn out to 'expensive' chips
I had a similar problem. I could burn the bootloader with no issue. When I uploaded a sketch it warned me "Board breadboard:avr:atmega328bb doesn't define a 'build.board' preference. Auto-set to: AVR_ATMEGA328BB'." But I also got the error "avrdude stk500_getsync()". This error means internal oscillator frequency is off. I reduced the upload baud rate to 19200 by editing "boards.txt" file. I was able to upload my sketch. The strange thing is that every time I want to upload a sketch, I need to burn the bootloader first and right after that upload the sketch otherwise I get an errror.
samakar:
The strange thing is that every time I want to upload a sketch, I need to burn the bootloader first and right after that upload the sketch otherwise I get an error.
Sounds like your auto-reset circuit isn't working.
When you burn a fresh bootloader it has nothing better to do than wait for an upload. Once it has uploaded a sketch it only spends a short time after Reset looking for a new upload before it passes control to the last sketch that was uploaded.
If your USB-to-Serial adapter has an RX light, just hold down the Reset button and start the upload. When the RX light blinks, release the Reset button. That will turn control over to the bootloader which will then catch the second or third try.
If you don't have a light to tell you when the PC is sending, try holding down the Reset until you see the message:
Sketch uses ____________
Global variables use _________
I've exactly the same issue as described by samakar.
I'm using the following environment:
- Atmega 328P-PU
- Arduino 1.6.9
- Breadboard 1.6
- Internal clock 8mhz
After burning the bootloader, I could upload the first sketch. The second upload fails. Resetting the board did not solve the issue. The strange thing is, that I'm also not seeing any serial input from my first sketch. So it seems the bootloader is broken after uploading a sketch. Is this possible?
I'm using other uC's with 16 Mhz (external) without problems.
What can I do to debug this in more detail?
OT:
The reason why I would like to change to 8 Mhz is the voltage. I would like to run it with 3.3V to power also a RF24 with it. 
I know that this could be very unstable, but with the Arduino Board 3.3V the RF24 is working fine after I've added a electolyt capacitor to it.
Thank you!
BR
pingu
I have no problem with an 8Mhz Atmega 328 following this tutorial
This is my entry from boards.txt
atmega328bb.name=ATmega328p on a breadboard (8 MHz internal clock)
atmega328bb.upload.protocol=arduino
atmega328bb.upload.tool=avrdude
atmega328bb.upload.maximum_size=30720
atmega328bb.upload.speed=57600
atmega328bb.build.mcu=atmega328p
atmega328bb.build.board=AVR_UNO
atmega328bb.build.f_cpu=8000000L
atmega328bb.build.core=arduino:arduino
atmega328bb.build.variant=arduino:standard
I use IDE 1.5.6
...R
Hi,
yesterday I've tested it again and the tutorial with 1.6 is working fine. I also know what went wrong before:
Never upload a sketch while the ArduinoBB is connected with the bootloader-burn layout. So after burning the bootloader, L should blink on the Arduino board. Turn off the Arduino, remove the AVR ISP, recable it to RX/TX as described and upload sketches. Otherwise it will break the bootloader.
For me it's working fine.
Please also ignore any custom board configuration. For the Atmega328P-PU the official example is working fine.
Additional, it doesn't matter if it's a SainSmart or cheap Atmega from ebay. I've used it with this and it's working.
I'm sorry for the confusion.
BR
pingu