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Topic: Standalone Atmega2560 (Read 1 time) previous topic - next topic

Jeffro_Aus

Hi,

I working on a project that will use a ATMEGA2560 standalone. It will be powered a 3.7V 2000mAh lipo battery boosted to 5V.

I'll be using the SparkFun FT232 breakout board for USB connectivity and a AVR Programming Adapter to bootload the chip.

I'll also be using a SPI real time clock, i2c device and the digital pins.

I was wondering whether my attached drawing looks correct? Am i missing any components?

Thanks for your time. I'd really appreciate any help.
Jeff

Nick Gammon

You should have a pull-up on Reset, just in case (say, 10K). I don't see a resistor in series with your "power" LED.
Please post technical questions on the forum, not by personal message. Thanks!

More info:
http://www.gammon.com.au/electronics

Jeffro_Aus

Thanks Nick for your response,

I've attached an updated diagram.

Would I need any pull-up resistors for the SDA and SCL lines?

Also, does it matter which transmit/ receive pins (I used TXDO/ RXDO) connect to the SparkFun FT232 breakout board? There are a number of these on this chip.

Cheers,
Jeff

Nick Gammon

If the I2C device doesn't have its own I would put 4.7K pull-up resistors on SDA and SCL.

The bootloader would expect to operate from TX0/RX0. If you aren't using the bootloader through the breakout it wouldn't matter, but if you are, it would.
Please post technical questions on the forum, not by personal message. Thanks!

More info:
http://www.gammon.com.au/electronics

Jeffro_Aus

Thanks for your response.

Can this point please be clarified.

Quote
The bootloader would expect to operate from TX0/RX0. If you aren't using the bootloader through the breakout it wouldn't matter, but if you are, it would.


Thank you

Nick Gammon

Is the FTDI interface for the purpose of bootloading?
Please post technical questions on the forum, not by personal message. Thanks!

More info:
http://www.gammon.com.au/electronics

Jeffro_Aus

Sorry for the delayed response.

I'm not sure if it's just my computer, but if I view an Arduino page (non forum pages) then try log into the forum, I cannot. It just loads to a white screen. Only when I log in directly before looking at any other (non forum pages) it works properly. I have to restart my computer to solve this.

Anyway,

I think I may be confusing myself with the 2560 solution.

I'll refer to http://arduino.cc/en/Tutorial/ArduinoToBreadboard to burn the bootloader using my Arduino Uno board, and also to upload my programs.

To confirm, by using this method, TXO and RXO from the 2560 can be connected in the same way as shown in the above link with no problem?

Thank you,
Jeff

Nick Gammon

I suppose, I haven't followed that exact link.
Please post technical questions on the forum, not by personal message. Thanks!

More info:
http://www.gammon.com.au/electronics

Jamal

Hi,

Is this a correct way to approach this:

1) Burn the bootloader: Referring to Nick's posting, http://www.gammon.com.au/forum/?id=11635

2) Upload programs: FT232 USB to Serial Board with RXO (atmega2560) to TX and TXO (atmega2560) to RX.

Thanks

Jamal

Can anyone please confirm my previous post?

Nick Gammon

What you have posted looks correct, subject to your having Rx and Tx the right way around. How about stating whether or not it is working?

If it is not, please post a clear photo of your setup.
Please post technical questions on the forum, not by personal message. Thanks!

More info:
http://www.gammon.com.au/electronics

Jamal

Ok thanks,

I'll need to confirm this once I receive all the parts I'll need.

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