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Topic: Could someone give me a tutorial on standalone atmega 2560? (Read 1 time) previous topic - next topic

Samuel10

I am trying to build a standalone with an atmega 2560. If someone can give me a tutorial or link to a tutorial with pictures that would be great!

Osgeld

http://arduino.cc/en/uploads/Main/arduino-mega2560_R3-schematic.pdf
http://arduino.cc/forum/index.php?action=unread;boards=2,3,4,5,67,6,7,8,9,10,11,66,12,13,15,14,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,86,87,89,1;ALL


dhenry

Quote
I am trying to build a standalone with an atmega 2560.


How to do it depends on what you want.

The simplest implementation requires the chip itself. and that's it.

Bells and whistles can be added but whether they should be depends on your applications.

Samuel10


Quote
I am trying to build a standalone with an atmega 2560.


How to do it depends on what you want.

The simplest implementation requires the chip itself. and that's it.

Bells and whistles can be added but whether they should be depends on your applications.


I am trying to build the simplest.

CrossRoads

I would put the chip on a breakout board, I think this one
http://www.schmartboard.com/index.asp?page=products_qfp&id=70

And add 16 MHz xtal, two 22 pf caps, 10K pullup resistor for reset, 4-6 100nF caps on the Vcc, AVCC, Aref,  and reset pin to bring out as DTR signal.
Connect 6 pins for ICSP - +5,GND, Reset, MISO, MOSI, SCK - and program away.
Designing & building electrical circuits for over 25 years. Check out the ATMega1284P based Bobuino and other '328P & '1284P creations & offerings at  www.crossroadsfencing.com/BobuinoRev17.
Arduino for Teens available at Amazon.com.


CrossRoads

Designing & building electrical circuits for over 25 years. Check out the ATMega1284P based Bobuino and other '328P & '1284P creations & offerings at  www.crossroadsfencing.com/BobuinoRev17.
Arduino for Teens available at Amazon.com.

Samuel10


I would put the chip on a breakout board, I think this one
http://www.schmartboard.com/index.asp?page=products_qfp&id=70

And add 16 MHz xtal, two 22 pf caps, 10K pullup resistor for reset, 4-6 100nF caps on the Vcc, AVCC, Aref,  and reset pin to bring out as DTR signal.
Connect 6 pins for ICSP - +5,GND, Reset, MISO, MOSI, SCK - and program away.

Are the resistors and caps necessary? Because I was able to make a standalone atmega 328 work with a 16 Mhz ceramic resonator and some wires.

CrossRoads

Parts addition depends on how stable you want your design to be.  I don't care to chase ghosts that a pullup resistor and decoupling caps would have eliminated.

Crystal/caps vs resonator - depends on your end use.  High speed comm's?  Accurate standalone time keeping clock (like 1 second/day drift)? Go with crystal.

Designing & building electrical circuits for over 25 years. Check out the ATMega1284P based Bobuino and other '328P & '1284P creations & offerings at  www.crossroadsfencing.com/BobuinoRev17.
Arduino for Teens available at Amazon.com.

Samuel10

#10
Jan 18, 2013, 06:05 am Last Edit: Jan 18, 2013, 06:08 am by Jason56 Reason: 1
Do you need the caps/resistors to burn a bootloader to it?
Note: I put it together using a crystal and hooked it up to an arduino uno board and a AVR isp mkII and it was unsuccessful.

Osgeld

caps and resistors are to make your chip more immune to external noise floating in the air, last time I did it with no caps and resistors the fuses got buggered up and it took me two evenings to figure out what had happened

capacitors are absolutely needed for the crystal unless using a resonator

seriously, your balking on like 4$ worth of parts if you bought them at the mall
http://arduino.cc/forum/index.php?action=unread;boards=2,3,4,5,67,6,7,8,9,10,11,66,12,13,15,14,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,86,87,89,1;ALL

CrossRoads

I always use them.  I never have problems.
16 MHz xtal, two 22pF caps,10K reset pullup resistor, 100nF caps on VCC, AVCC. 100nF cap from Reset to DTR if doing serial downloads. Diode across reset resistor if using a reset switch.
Designing & building electrical circuits for over 25 years. Check out the ATMega1284P based Bobuino and other '328P & '1284P creations & offerings at  www.crossroadsfencing.com/BobuinoRev17.
Arduino for Teens available at Amazon.com.

CrossRoads

#13
Jan 18, 2013, 08:15 am Last Edit: Jan 18, 2013, 08:19 am by CrossRoads Reason: 1
2560 has more Vcc pins, put 100nF cap on each one.
Designing & building electrical circuits for over 25 years. Check out the ATMega1284P based Bobuino and other '328P & '1284P creations & offerings at  www.crossroadsfencing.com/BobuinoRev17.
Arduino for Teens available at Amazon.com.

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