Arduino MEGA and TFT 3,5, cannot start SD

Other Hardware Displays
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Hello everyone,
I have a brand new Arduino Mega (clone) and I´m trying ti display an image on it. All the examples work fine and display is up and running, however when I try to upload the "showBMP_not_UNO.ino" from the examples, after upload it says
Show BMP files on TFT with ID:0x9486
cannot start SD

The display is https://techfun.sk/produkt/tft-display-shield-3-5-pre-arduino-uno-s-sd-kartou/ and all other examples work fine.

I´ve uninstalled the Adafruit SD library, so the only one in use is sdFat the most recent version.

I´ve checked this with friend and he hasn´t found any connection issues and we both think that pinout is working fine, as all other examples work OK.

I don´t have another SD card, the current one is from old Nokia phone 2 GB and formatted with FAT32.

Hoping it´s some basic issue I can solve pretty straight-forward

Thank you very much in forward for any help

showBMP_not_Uno.ino (10.0 KB)

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You are likely to get faster help if you post the code properly.

Please read the forum guidelines to see how to properly post code and some information on making a good post.

Use the IDE autoformat tool (ctrl-t or Tools, Auto format) before posting code in code tags.

Please post a schematic. Hand drawn, photographed and posted is fine. Include all pin names/numbers, components, their part numbers and/or values and power supplies.

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I´ve included the display I´m using and the code is just taken from the examples of the library used. The post has all the relevant info.

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Alright, I will reply myself here and hopefully this will help somebody later on, I got it working! :slight_smile:

Firstly, I found out that Mega has the SPI pins 50-53. I'm not very skilled Arduino developer, but we all learn every day. Mistake #1 - bought a display for Uno as I needed it before Christmas and was ordering it on 21st :roll_eyes:
The core thing here was that even though I defined the SD_CS pin in a config as pin 10 (which is actually on the original shield correct for this operation), Mega didn't care about that. Once I correctly connected these 4 pins, I got a communication with the CardInfo.ino that is from the original SD library. As I was aware that I have to use the sdFat because of Mega, I needed to somehow find out why the sdFat library doesn´t work for me.
Mistake #2 - you don´t really need sdFat library in order to get this running.

The truth is, even though for the original SD Library CardInfo went fine and I was able to communicate with the SD card, for some reason with the same wiring and connections, the sdFat library just doesn´t work. I can´t connect to the SD card at all.

SD errorCode: SD_CARD_ERROR_INVALID_CARD_CONFIG = 0x2b
SD errorData = 0x0

So I gave up and started looking for a way how to use the original SD library, as this was working for me fine.

Basically, this video says it all Arduino Mega 2560 + MCUFriend 3.5" TFT: DIY Gauges, read bmp imagines from SD - YouTube. I wish I could’ve find it two days ago :joy:

The thing is - even though you're using MEGA and not UNO, you can use the same file from examples showBMP_kbv_Uno. You just need to define the SD_CS pin and you're good to go! The sdFat library is still dead for me, but I don´t need it anyway.

I´ve attached a working ino file.

Time for a beer,
showBMP_kbv_Uno_edited_for_Mega.ino (9.5 KB)
Merry Christmas!

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