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Topic: How to burn the bootloader and sketches on Atmega328p-Au (Read 3854 times) previous topic - next topic

Mohamed96

Hi guys, i am building a custom arduino compatible board, and i'm using the atmega328p-Au chip.
I am powering the board with a 3.7 lipo battery, and i was wondering if i could still use the 16 mhz external oscillator even if the chip will be powered with 3.3v (i'll use a voltage regulator).
Second question:
How am i suppose to burn the bootloader and upload sketches into the chip? I should make ICSP or FTDI headers? Which one will be able to burn bootloader and upload sketches? Thanks!

raschemmel

Arduino UNOs, Pro-Minis, ATMega328, ATtiny85, LCDs, MCP4162, keypads,<br />DS18B20s,74c922,nRF24L01, RS232, SD card, RC fixed wing, quadcopter

floresta

As stated above the device is rated for 8 MHz at 3.3v but you will probably find that it will work at 16 MHz.  I wouldn't recommend doing that for a commercial design but I know that the Moteino devices that I bought are working fine under those conditions.

You will need the ICSP connections to burn the bootloader.  You can use either the ICSP or the FTDI connections to upload sketches.


Don

Mohamed96

Ok, now it's more clear, thank you.
But can i still use the Arduino IDE to upload sketches though the ICSP?

raschemmel

Quote
How am i suppose to burn the bootloader and upload sketches into the chip? I should make ICSP or FTDI headers? Which one will be able to burn bootloader and upload sketches? Thanks! 


I use an FTDI Basic from Sparkfun to load sketches in my ATmega328-PU .
without it,
  http://www.open-electronics.org/arduino-isp-in-system-programming-and-stand-alone-circuits/
Arduino UNOs, Pro-Minis, ATMega328, ATtiny85, LCDs, MCP4162, keypads,<br />DS18B20s,74c922,nRF24L01, RS232, SD card, RC fixed wing, quadcopter

liuzengqiang


I believe the maximum speed at 3.3V is 8 Mhz.



Not according to spec sheet. You can safely go up to about 13MHz with 3.3V supply. 16MHz will be overclocking.

Serial LCD keypad panel,phi_prompt user interface library,SDI-12 USB Adapter

floresta

Quote
Not according to spec sheet. You can safely go up to about 13MHz with 3.3V supply. 16MHz will be overclocking.


That would explain why they seem to be pretty successful running at 16 Mhz.  It's a relatively small amount of overclocking.

Don

liuzengqiang

Maybe enough cooling will help the overclocking.
Serial LCD keypad panel,phi_prompt user interface library,SDI-12 USB Adapter

CrossRoads

Maybe small - not all functionality is guaranteed to work when underpowered & over clocked.
Serial functionality usually takes a hit, has been reported here before.
Designing & building electrical circuits for over 25 years.  Screw Shield for Mega/Due/Uno,  Bobuino with ATMega1284P, & other '328P & '1284P creations & offerings at  my website.

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