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Adafruit 1.8" TFT Shield/SD/Joystick on a Mega2560

by robwlakes on Wed Oct 30, 2013 10:43 pm

Hi Folks,
I have a homebrew shield for the above TFT screen on a prototyping shield (using a breakout version of the TFT screen+miniSD) on a Mega 2560. It is connected to pins 51-54 SPI. It works really good, but I would like to upgrade to Adafruits 1.8" 18-bit Color TFT Shield w/microSD and Joystick - ID: 802. The micro SD+Joystick is a very attractive addition to my project.

However my concern is that the combo board from Adafruit will have dedicated SPI connections for the Aduino Uno and I will not be able to use the dedicated SPI pins for the Mega.

Does the combo board have means to adapt the connections to the optimised SPI on a Mega 2560? I don't want to have to butcher a brand new board. Speed of access is important as I need to quickly and regularly update the screen while the program runs. Mega is important for greater SRAM.

Cheers, Rob
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Re: Adafruit 1.8" TFT Shield/SD/Joystick on a Mega2560

by adafruit_support_bill on Thu Oct 31, 2013 4:34 am

You could bend the SPI pins out and run 'fly wire' jumpers. A bit ugly, but less butchery compared to cutting traces.
The cleanest way would be to stack it on a Mega proto-shield. Cut the Uno SPI pins on the proto shield and run jumpers to the Mega spi pins using the breakout holes.
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Re: Adafruit 1.8" TFT Shield/SD/Joystick on a Mega2560

by robwlakes on Thu Oct 31, 2013 6:45 am

Thanks, those are some practical solutions.
You have given me an idea.
Would it be possible to buy the combo board without soldered pins. I could then only put in the ones I need, and use flying connections for the SPI connectors?
Some companies offer their boards with unsoldered pins.
Removing pins that have been soldered in could be messy & risky.

Rob
ps The pins are only header pins aren't they? They would extract much easier ie one at a time if pulled through than the stackable headers.
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Re: Adafruit 1.8" TFT Shield/SD/Joystick on a Mega2560

by adafruit_support_bill on Thu Oct 31, 2013 7:17 am

Actually, it does come with the headers separate: http://learn.adafruit.com/1-8-tft-displ ... the-shield
Just leave out the pins you don't want and solder jumpers to the holes. :D
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Re: Adafruit 1.8" TFT Shield/SD/Joystick on a Mega2560

by robwlakes on Thu Oct 31, 2013 3:54 pm

:D Excellent. Consider it a done deal. Cheers, Rob

PS It may be worthwhile to mention this technique in the instructions shown above, and how to make use of the Mega2650 SPI hardware and what pins are best to use. Maybe even mention it on the advertisement as I think it is photographed 5 out of the 6 times with pins soldered in.

It certainly goes well on my Mega.
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Re: Adafruit 1.8" TFT Shield/SD/Joystick on a Mega2560

by adafruit_support_bill on Fri Nov 01, 2013 5:09 am

Good idea! Thanks for the suggestion. :)
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