I need help on what I need to buy for my project.

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JMC17
 
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I need help on what I need to buy for my project.

Post by JMC17 »

Hey there!

I'm working on an arduino project and I need some pointers.
I want to buy a 7" capacitive display and an SD card for it but it has to work on Arduino, I don't have a raspberry pi yet!
Do I need a shield? Which one?
I'd appreciate links to what I need to buy.

Also I've read that you don't sell outside of the US? Is that true?
When I add stuff to my cart and try to buy it, it seems to work just fine for Canada..

Sorry to put that on your shoulders guys, I wish there was an actual customer support.
I just needed someone to hold my hand while I buy stuff.

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dastels
 
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Re: I need help on what I need to buy for my project.

Post by dastels »

The closest thing in the shop is https://www.adafruit.com/product/2354 with is a 7" 800x480 with a resistive touchscreen. You would need the controller board to handle the display: https://www.adafruit.com/product/1590. It doesn't have an SD card on it, but that's pretty easy to add (usually needing just one additional digital output for the SPI select. But to add another SPI device (i.e. the SD card) you'll need a bit more circuitry as noted in the technical details section of the controller board page.

As for selling outside the US, that's not a problem. You might want to look for a more local distributor to maybe save a bit of $: https://www.adafruit.com/distributors#N ... ica-Canada

Dave

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JMC17
 
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Re: I need help on what I need to buy for my project.

Post by JMC17 »

Thanks Dave!
Resistive will do the job.
I'll look up about installing the SD reader because it's pretty essential for my project.

There will be a bunch of stored images on it. I'm making a shortcut tablet/gaming feedback display.
In other words, I set icons/menus on the display, when tapped, I send through serial ports the data required for my c# program on PC to start a process or open a folder.
As for the gaming feedback, I read the process memory and get the values I need, then print them on the display.
While I can do all that without an SD card, I really enjoy photoshopping and making interfaces, which is why I need extra storage.

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dastels
 
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Re: I need help on what I need to buy for my project.

Post by dastels »

It's just one chip you have to add, not complex but essential due to the design of the display board.

Dave

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JMC17
 
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Re: I need help on what I need to buy for my project.

Post by JMC17 »

So, while waiting on support for my other issues, I've been fiddling with the SD card reader.
I now see what you mean by needing more circuitry.
There's not enough SPI pins to plug both. I followed the link in the technical details about tri-state but none of it was clear to me.
What's the solution exactly? What do I need to do to get both connected?
Attachments
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dastels
 
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Re: I need help on what I need to buy for my project.

Post by dastels »

As described in that link, the display board doesn't tri-state its MISO/CIPO pin, meaning it doesn't disconnect it from the bus. MISO/CIPO is the data signal from SPI devices to the controller. Because of that you can't connect other SPI devices to the bus that the display board is on. SPI devices really should tristate/disconnect their output in response to the select (CS) signal. So to use this display along with another SPI device such as the SD card, you need to add a tristate chip that is controlled by the chip select for the display. See https://learn.adafruit.com/digital-circ ... ate-buffer for more about tri-state.

You should have plenty of pins. The SCLK, MISO/CIPO, and MOSI/COPI pins are shared with all SPI devices (which is why you need to tri-state the display's MISO/CIPO). Each SPI device needs its own CS (chip select) pin which is just a digital output. Some devices need another pin or so. You have a Mega class board so you have tons of digital I/O.

Dave

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JMC17
 
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Re: I need help on what I need to buy for my project.

Post by JMC17 »

Thanks a lot Dave!
Is this the correct chip?
https://www.digikey.ca/en/products/deta ... 44N/277199

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dastels
 
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Re: I need help on what I need to buy for my project.

Post by dastels »

This one is smaller, simpler, and cheaper, and the one suggested: https://www.digikey.ca/en/products/deta ... 25N/277218.

you only need one bit, wasting 3 is better than wasting 7.

Dave

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JMC17
 
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Re: I need help on what I need to buy for my project.

Post by JMC17 »

Ah! Thanks. You're the best Dave.

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