Is the process of burning a bootloader (JChristensen's mighty-1284 to be precise), on an Atmega1284 microcontroller same for both DIP (Atmega1284p) and tqfp (Atmega1284-au)?

While searching online I found very little information about the tqfp version of the chip.

Also, I would like to use internal or external 8 Mhz oscillator (crystal) as my board should run at 3.7V from lithium ion battery charged with MCP73831 lipo charging chip. Should I just change the fuse settings in the Arduino IDE boards.txt file (and should I use the fuse bits from Atmega1284 datasheet) or there is something else that also should be done?

Here are my schematics:

One whole sheet from the schematics

Closer look on Atmega1284

  • \$\begingroup\$ You say you want to use the internal OR the external crystal but you don't have a crystal attached to your ATmega1284 MCU. I just want to clarify, are you asking a question as to if you should use the internal crystal or not? As it stands right now, you have to since you don't have an external crystal \$\endgroup\$ – Funkyguy Dec 17 '15 at 22:26
  • \$\begingroup\$ Also there shouldn't be any differences in how the MCU operates between the packages apart from losing some interfaces or extra GPIO pins. This is why you found so little information regarding the TQFP version specifically. They are in the same datasheet \$\endgroup\$ – Funkyguy Dec 17 '15 at 22:27
  • \$\begingroup\$ @Funkguy Either would be fine to me. If I find some space for it on the PCB, it should be easy to add an external crystal. \$\endgroup\$ – Marko Scekic Dec 17 '15 at 22:29
  • \$\begingroup\$ Okay and your V+ to VCC power supply, what is the VCC voltage at? IS that going to 3.3V or something different? \$\endgroup\$ – Funkyguy Dec 17 '15 at 22:32
  • \$\begingroup\$ Vcc should be 3.3V. It comes form the output of the voltage regulator that's connected to the battery V+ (typicaly from 4.2v to 3.4V) \$\endgroup\$ – Marko Scekic Dec 17 '15 at 22:35
  1. Yes it should be functionally identical (apart from the pin numbers, which look correct for the TQFP in your schematic anyway.)
  2. You can use this tool to work out what the fuse values should be. In particular the clock selection should be "Internal RC Oscillator" and the "Divide clock by 8 internally" should be disabled (The Int. RC Osc is 8Mhz.)

Not sure about boards.txt as I don't use the Arduino IDE.

Also I recommend http://arduino.stackexchange.com


Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.