Arduino Mega + Ethernet Shield installation

Hi all,

I am using an Arduino Mega together with an Ethernet shield and I am now trying to figure out the best way to install a third PCB probably based on the Arduino MEGA Proto Shield.

The Ethernet shield is shorter than the Mega and if installed on top of the Mega, then there is no connection to a number of pins on the bottom side of the Mega board.

This would drive me to install firstly the proto shield on the Mega followed by the Ethernet shield on top.

However this method: 1. Gives limited physical access to the proto shield (since it is covered by the ethernet shield), 2. Poses height restrictions on the components on the proto shield which is now 'sandwiched' 3. Necessitates the provision for connection of the ICSP header that the Ehternet shield uses through the proto shield.

Anyone faced this issue before? Which is the best practice ?

The W5100 chip gets warm (hot). If you add a board on top of that, the cooling is less. I would not recommend that. For the pins that are not covered by the Ethernet Shield, you could add an extra board-in-between with long pin headers. You would have a total of 4 pcb board, and the height is 3 boards. Perhaps you have to add a fan for the W5100.

The protoboard in between is a good option. You have to add the ICSP header of course.

Another option is not using A0...A8 and not pin 0 to 13. Add the Ethernet Shield and make a board for the remaining pins. Any prototype pcb will do, since there everything is normal 1/10" spaced. Make that board big and place the components outside the pins. The total height will only be two pcb boards. The GND and +5V are available, so are the I2C bus, the SPI bus, the analog inputs A8...A15, and the three serial ports, and many digital pins. That board needs an empty area to be able to insert the microSD card. That is why the components needs to be outside the pins.

Thanks for your message, but ...

The GND and +5V are available, ...

Are they really? The power header is now under the Ethernet shield only.

In fact this is the approach i thought of as well but it doesn't look too good since the overall size of the system increases in length as the new pcb needs to extend beyond the length of the mega

Yes, the total size is larger. At the ends of the double header are two GND and +5V pins. https://www.arduino.cc/en/Main/arduinoBoardMega2560

Watcher: Hi all,

I am using an Arduino Mega together with an Ethernet shield and I am now trying to figure out the best way to install a third PCB probably based on the Arduino MEGA Proto Shield.

The Ethernet shield is shorter than the Mega and if installed on top of the Mega, then there is no connection to a number of pins on the bottom side of the Mega board.

This would drive me to install firstly the proto shield on the Mega followed by the Ethernet shield on top.

However this method: 1. Gives limited physical access to the proto shield (since it is covered by the ethernet shield), 2. Poses height restrictions on the components on the proto shield which is now 'sandwiched' 3. Necessitates the provision for connection of the ICSP header that the Ehternet shield uses through the proto shield.

Anyone faced this issue before? Which is the best practice ?

I am facing this exact same issue right now.

I'm considering building a pcb and using surface mount components (solves issue 2). I placed components on the bottom of the pcb. I might have to rearrange a bit more, but you get the idea. As to issue 1, I move all my pin headers to the end part of the shield. As to issue 3, I am thinking of cutting a hole through the pcb for the ethernet shield icsp conneciton.

something like this |500x298

The ICSP header is a normal header with long pins, soldered to the bottom.

Peter_n: The ICSP header is a normal header with long pins, soldered to the bottom.

in my case, I have a height restriction, so total height cannot be more than the ethernet shield stacked on top of the mega. My shield does not need the icsp connection, so I plan to just cut a hole where the icsp connector goes so the ethernet shield can still connect to the mega icsp. In theory, I think it is possible to sandwich the custom pcb between the ethernet shield and mega in order to maintain the same total height, but I'll know for sure if it will work once I get the pcb to test.

Some good ideas there doughboy. In my case i was hoping to get away with using a stripboard instead of designing a proper pcb. Out of curiosity, which pcb software are you using? Who then makes your pcbs?

Watcher: Some good ideas there doughboy. In my case i was hoping to get away with using a stripboard instead of designing a proper pcb. Out of curiosity, which pcb software are you using? Who then makes your pcbs?

yeah, you need to think outside the box on this one. I use eagle pcb, you will need to pay for license if you exceed the free version pcb size. I just tried my first pcb order with dirtypcb and still waiting for it. If it comes out fine, then I will order this pcb from them again.

I use eagle too. had pcbs done in fusion pcb in china. Min order 10 pcs I think

fusion = seeedstudio.
If dirtypcb does not work out, that is the next place I am using.
dirtypcb is $25 for 10, fusion is $31 for 10 shipped. I figure the difference will add up if it takes me multiple iterations to get the pcb right.

True. It took me 3 tries already to get a working version and I can still find some mistakes!!