DIY Arduino Mega 2560 or 1280

So this is my first instructables.... Let's try this!

*original can be found here: http://tsjwang.blogspot.com/2013/08/diy-arduino-mega-2560.html*

Alright.
Here's the story: I was working on this frustrating Arduino project, and I decided to take a break. I went away to watch a little Star Trek and drink some water.
When I came back, my Arduino Mega was hot: really hot.

The Arduino was not responding to the IDE. The only way I could program it was by using the USBtiny ISP.
That pretty much ruins the purpose of an arduino board, so I brought out the solder pot, desoldered the whole board, salvaging as many parts as I could.
Since the ATmega 2560 was not damaged, I decided to put it back to use:
The following is the process of how to...

Step 1: Make Your Own Arduino Mega

You think it's hard to solder SMD? Think again. This was my first time soldering SMD chips with 0.5mm pitch (in other words, REALLY SMALL).

Parts needed:
- ATMega1280 or 2560 Microcontroller (I recommend the ATMega1280, so you can use Arduino IDE to program)
- TQFP100, 0.5mm pitch to DIP adapter
- Momentary push button
- 6 headers (for ISP)
- lots of wires
- flux
- Perfboard
- 16 MHZ crystal (if you salvaged chip from Arduino Mega)
- OPTIONAL but recommended - double sided tape
- OPTIONAL - 330 - 470 ohm resistors *2
- OPTIONAL - two LEDS
- OPTIONAL - 5 more headers for FTDI Serial communication
- OPTIONAL - nuts and bolts

Step 2: Stick It On

Stick one or two pieces of square double sided tape on the breakout board. This might help keep the chip in place when soldering it.

Step 3: Placement

Place the chip on! Please note the index corner on the chip to align it correctly. Make sure that the leads on the chip and the board line up REALLY well. The must be aligned.

Step 4: Smother in Flux

Time to start the soldering: apply WAY TOO MUCH flux (that means A LOT) onto the edges of the chip. You will need to use all of it, and maybe some more.

Step 5: Drag the Solder

I do not have pictures for this. You will want to put a nice drop of solder on your iron and just drag it across the edges of the chip. Don't worry, it's all being soldered, even if you do not think it is.
You will probably have many solder bridges (especially on a chip this small).
Thats OK, just gently drag it off with the iron tip, use a solder sucker (be careful with it, you might bend the leads), or use even more flux to remove it. This step might be the most difficult

This video:

Tells you how to do it. Instead of soldering lead by lead, I just dragged it down. It seemed to work well.


Then after that, follow the instructions on the pictures.

Step 6: Pinouts....

This step is mildly annoying. Print out the datasheet of the 2560 and start marking where
MOSI
MISO
SCK
TXD0
RXD0
pin#27
VCC
GND

or any pins important to you, are
Mark it all!

Step 7: If You Prefer to Perfboard It...

Start preparing your perf board. This step is very subjective to your needs and tastes. I like to have the TX and RX header so I can program this like a regular arduino.
I like to have a reset button
I like to have an LED on pin D13/ 27 of the chip
After all, it is a development board.

Step 8: Test It Out!

Hopefully you have an AVR programmer that uses the 6 pin ISP.
Plug it in, type in

avrdude -c PROGRAMMER -p m2560 OR 1280 DEPENDING ON WHAT YOU HAVE 

Does it recognize?

If so, BRAVO
if not... check your wires. 

After you get it working, check your serial communication (This only applies to people who desoldered the m2560 from their old Arduino Mega. For people who are ordering the chip straight out of the factory, there is no bootloader inside of the chip that supports serial programming.)

**
After I plugged in my board to the FTDI converter, the m2560 started spitting out strings from the last program that I was running on it.

Good times....

Step 9: Finished... Confession

So, if you were working with the ATMega 1280, you can just plug it in and burn the bootloader to it.
That would be "Arduino Mega"

If you were using the ATMega 2560... Uh oh...
You see the Arduino Mega 2560 board has an ATMega 8 or 16 as the UART. In this instructables I was using an FTDI converter.

I would have continued to make some board support for this DIY Mega, however.... it burnt out.


When soldering in the oscillator crystal, make sure it DOES NOT SHORT THE LEADS. Note that it has a metal casing, so it should either be masked with electrical tape or place in another area.


That ended up shorting XTAL 1 and 2, Vcc, and GND all together. The chip smoked and I wasted a lot of effort.

As long as you follow all of these instructions, however, you will be able to accomplish what I would have if I have not made that mistake!


In other words

I shorted something by accident. If all of you out there remember not to short anything, your mega will work. If you do what I did, by putting the crystal in the wrong place and shorting it, it will not work.

Comments

[carlos66ba]

Nicely done. But why didn't you simply change the burned part rather than toss everything out?

[TSJWang]

Hi Carlos,

I actually tried to identify the burned part. After I replaced the resistor, something else was heating up.
I decided that it wasn't worth the hassle to replace every single part in that part of the board.
So I desoldered every part, kept them (for the future), kept the un-populated board as a memoir, and made this!

Good suggestion though. I wish I knew what was burnt!

[carlos66ba]

Thanks for the reply! Your set-up looks nice, I dread soldering surface mount components :) (too small to see!)

[LiedsonA]

Hello, I am looking for someone who could help me on a project,
I have an SSD1322 display that is used to manage the volume / selection of audio sources and filters. The display is connected to a small card or there is a mega 2560 on it
(Maybe it should contain the display program?)

My question is can we reprogram this SSD1322 display?

I can possibly pay the person who can help me
Here is my contact email [e-mail]
thank you

[TSJWang]

Hi,

If it is indeed a microcontroller, I'm sure it could be reprogrammed. How easy that will be is another question.

If there is documentation that would make it much easier.

[afridave]

any idea why the mega got hot to start with?.....I have the same problem with my uno.....will not download...gets hot when plugged into the usb....and after a while the light go really dim.... ..however the last program I loaded still runs when plugged into battery power...so I assume the chip is still functioning fine....so I figure ill diy a uno someday...

[TSJWang]

When there's heat that means there's a lot of energy being wasted.
That probably means there's a short in the board: either inside a component or on the traces.
I think what's happening with your Arduino is some component(s) between the USB and ATMega are broken. When you run it off battery, you bypass those components and nothing heats up.

Be careful with the heat! You might want a new Arduino to prevent breaking your computer's USB port or anything else.

[afridave]

THANKS MR WANG....already have new uno....and have recently purchases the dr robot bluno mega...would however like to salvage what I can from the fried uno....if the chip is still good its highly possible to easily rebuild.....

[Nasser768]

Can you share the circuit schematic please ?

[TSJWang]

I didn't have a schematic: it was very arbitrary.

If you look at the datasheet for the 2560, you can decide what features you want to have.

Here is the original schematic of the Arduino Mega: https://www.arduino.cc/en/uploads/Main/arduino-mega2560_R3-sch.pdf

[DannyV33]

I was curious if you were to order the chip from the manufacturer instead of desoldering it from an Arduino Mega...How would you add a Bootloader for serial communication, if that is even possible?

[TSJWang]

Hi,

Towards the end of the instructable I talk about how I solder ISP programming pins. If you have an ISP programmer you can burn the bootloader that way.

[3000eleck]

Can I use AVRISP mkii as programmer in arduino IDE to burn bootloader...

[TSJWang]

I think so, you just need to change what programmer you are using in the IDE.

[PiotrG7]

Can you tell me, which one pins and wires do you connect in step 7? I can't see anything on photos, and don't have to burn the atmega ;D

[TSJWang]

That's a difficult one.
If you look at the pinout in step 6 that might help.
Basically you want to wire up the following things
- XTAL oscillator clock crystal
- ISP Programming port
- Reset button to reset
- LED on pin 13
- TX RX and other UART pins to the UART header
- idiot lamp

[EirikB1]

When you came to the part with flux, at first it looked like you had totally melted the chip XD

[Rocker517]

A few more questions. What are the six pins that you said you couldn't use. And could you explain the wiring. And also why couldn't you use the Arduino IDE for the 2560 chip. And if I use the 1280, do I need to use AVR Studio, or can I use the official IDE instead?

[TSJWang]

I'm not sure what you mean by the six pins, but there are six pin ISP cables for programming if that is what you are asking about.

I couldn't use the Arduino IDE because I probably burnt out the UART part of the Arduino. This means that I could not program it through the USB port anymore, and I could only program it with the ISP.

You can use the official IDE for the 1280. I think there is an option in the Boards menu for that.

Thanks for your questions!

[Rocker517]

Could you go into more detail for the wiring to the perf board?

Thanks