Adafruit 2.8" TFT LCD Shield vs Arduino Mega

[Dean98671]

Hi guys,
just double checking here before I go any further (sorry if this has been covered elsewhere - but I couldn’t find any references). I have just received the Adafruit 2.8" TFT LCD shield, and it works perfectly with my Arduino Uno - beautiful screen. I’m keen to hook it up to my Arduino Mega, but it looks like I need to cut the Pin 11 / 12 / 13 pads on the back, and solder bridge the ICSP pads on the back.

Just checking that this is correct for the Mega, and also if I do this, if the ICSP header pins will no longer be required in any way for the TFT screen to function. I’d like to use a screw shield between the Mega and the TFT, which will allow me access to other pins that the LCD will otherwise be covering. If I use the screw shield, the ICSP pins won’t connect between the TFT and the Mega - the screw shield elevates the TFT so that the ICSP header pins won’t physically be able to meet between the TFT and the Mega.

Thanks in advance!

[Bryce]

Hey Dean,

Could you send us some images of the project so we can take a look at what we can do to fix this issue. I don’t know whether the board is designed to suit an Arduino Mega but I see no reason why it shouldn’t. It’ll likely just require some modding first. Have an awesome day!

Bryce
Support | Core Electronics

[Dean98671]

Thanks Bryce,

I’ve looked at all of the doco that I can find from Adafruit,
and it seems to indicate that the shield supports the Mega. It’s just a little
ambiguous as to what’s required to make it work. They even have a picture of
the shield installed on a mega. It looks like I need to cut the pin 11-13
traces, and bridge solder ICSP pin pads on the back of the shield - but the
doco intimates that this is actually for resistive vs capacitive
functionality. Looking at the back of the shield, the PCB is printed with very
brief instructions showing that I need to cut the pin 11-13 traces, and solder bridge
the ICSP pads for it to work on a mega. I’m not sure if I lose the SD reader
functionality on the mega or if it will still be fine if I do this.

Ideally, I’d like to just use it on a Uno, but I’m not going to
have enough memory for my project, as just the basic functionality for using
the screen with SD reader takes up 72% program space on a Uno - and I know my
weather station project using a basic 128x64 graphic LCD panel already uses 68%
memory on a Uno - and it’s 600 lines of code. I’m pretty sure that I’m going
to need the mega. It looks like the libraries for the Adafruit shield take up
a lot of space.

So, down to details. If you look here on the Adafruit site:

https://learn.adafruit.com/adafruit-2-8-tft-touch-shield-v2/connecting

There’s a subsection titled Using with an Uno R3,
Leonardo, Mega

Because
the TFT is about the same size as an Arduino, we pre-assemble the shield in the
factory. For the Capacitive Touch, to use, simply place it onto your Arduino
Uno/Duemilanove/compatible. No wiring, no soldering! Bam! For the Resistive
touch, you will need to cut the traces between 11-13 and solder bridge the ICSP
pins.

This is where there’s a pic of the shield installed on a Mega. So
this is intimating that the mod is for resistive touch to work and doesn’t
actually make any mention of the Mega. However the back of the shield does -
see attached pic.

I’m sure I’ve read something about the functionality of the card
reader on the shield not working on a Mega though. However, I’ve read a lot of
stuff on this subject now, and could be mistaken.

My actual project only has two sensors required - BME280 SCL/SDA
and a DS1307 SCL/SDA. That’s it. Pins aren’t the problem for me - just
memory. Whilst I’m yet to convert my existing Uno weather project across from
the blue / white 128x64 graphic LCD - it’s looking dicey re me having enough
memory on the Uno if I use the Adafruit TFT shield.

I’ve included a few shots of the shield installed on a UNO (and
it works perfectly btw - beautiful screen). I’m really just hesitant to do any
mods to get it working on the mega until I’m sure that I’m doing the right
thing.

I haven’t yet converted my existing code across to use the
Adafruit shield, so it may not be worth including it.

DC

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