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:
There’s a subsection titled Using with an Uno R3,
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
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
I haven’t yet converted my existing code across to use the
Adafruit shield, so it may not be worth including it.
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