SD Card shorts the TFT LCD SPI?

Hi folks,

I'm trying to figure out how to enable SD card part of the 2.4'' TFT SPI 240x320. Whenever I insert the SD card the screen goes black and I can feel that U2 (voltage regulator) is getting super hot. Fortunately, nothing blows out.

I tried to connect it to 5V, 3v3. I tried to shorten J1, but nothing has changed.

Has anyone faced similar issues?

Welcome, your camera does a nice job with Red! I have no idea of what you showing or are using to operate this thing and what is connected to what. You state: "Fortunately, nothing blows out." Are you sure, things blow out without releasing smoke. A schematic, not a frizzy picture would be a big help. I know ROHS is not the name, telling us that would help as well as links to technical information. Places like azon are useless as all they show is sales info.

Please post a link to more information about that board. If you have no such information you better buy another card that comes with a data sheet, Arduino library and example code.

Some SD card modules don't disable their MISO output as they should.

Unfortunately, I don't have the datasheet. It's a Chinese no-name product. It's ILI9341-compatible and I got the LCD working.

I made the following experiment:

  1. I connected VCC, GND, and LED to the TFT part.
  2. LCD backlight lights.
  3. Whenever I put the SD card, it goes down.

Thanks for the excellent photo. I don't see any evidence of soldering SD_SCK, SD_MISO, ... or of configuring J1.

  1. Never short J1 unless there is no 5V supply. U2 provides 3.3V to TFT and SD
  2. try a different SD Card. if OK the 1st SD is faulty
  3. if a 2nd SD gives the same problem the SD holder is faulty. e.g. silver paper stuck in the holder.

Note that these Red displays normally contain an Ilitek ILI9341 controller but recent boards have appeared with Sitronix ST7789.
ILI9341 must have 3.3V logic signals from the Arduino. e.g. from Zero, Due, Teensy, ...

If you have a 5V Uno, Mega2560, ... you should use level-shifters on every logic signal.
It is a popular Display. Many people have shown how to "level shift" e.g. resistor dividers, custom chips, ...

David.

p.s. I advise against shorting J1 because one day you will connect VCC to 5V (with J1 shorted). This is guaranteed to destroy a SD card and damage the ILI9341.

p.p.s. your photo is fine. we can recognise your display.
if Adafruit_ILI9341 library examples work 100% you have wired correctly and it is not ST7789
all SD cards handle MISO properly. Both ILI9341 and ST7789 handle MISO properly.

Hi David,

Thank you for taking a look!

p.p.s. your photo is fine. we can recognise your display.

I haven't found schematics for v1.2. The closest I can go is 2.4inch SPI Module ILI9341 SKU:MSP2402 - LCD wiki

Note that these Red displays normally contain an Ilitek ILI9341 controller but recent boards have appeared with Sitronix ST7789.

I managed to get it working with the ILI9341 driver code.

  1. if a 2nd SD gives the same problem the SD holder is faulty. e.g. silver paper stuck in the holder.

I tried using the 3v3 power supply from an external source and directly from ESP32-WROVER, but it gives same results. I don't operate with 5v now.

  1. if a 2nd SD gives the same problem the SD holder is faulty. e.g. silver paper stuck in the holder.

I checked with multiple SD cards, and always achieved the same results. I will try to desolder the holder and see if everything is correct there.

p.s. I advise against shorting J1 because one day you will connect VCC to 5V (with J1 shorted). This is guaranteed to destroy a SD card and damage the ILI9341.

Thank you for the hint! Safety first :slight_smile:

When you are suspicious of a short or high current. Don't use a "stronger" supply. Insert a small series resistor to limit the current e.g. 10R

The backlight might take 100mA. TFT 20mA. SD 20mA. U2 should never get hot.

First off. Check U2 for 3.3V output.
Check the solder traces from the SD holder. e.g. for bridges between adjacent traces etc.

If the problem only occurs when you insert the SD there is wire / silver paper that only makes contact when you push the SD card in.
I don't know anyone that willingly buys monster SD cards. They generally use microSD in an Adapter. Change the Adapter.

Obviously test the other SD / microSD in a working system first.

David.

1 Like

I measured more values.

Without SD card, U2 has:

3.19v and 0v / 3.06v

With SD card
2.28v and 0v / 0.97v

If I use a 5v power supply, without SD card it's 4.2v and 0v / 3.29v, but no changes with the card (2.2v and 0v / 1v).

EDIT:

Interesting observation, the SD card is also an adapter and it without the microSD card, it doesn't short the circuit.

Change the Adapter !

Remove SD from Display. i.e. examine bare component on your desk. (unpowered)
You can measure the microSD with and without Adapter i.e. measure resistance between pins with DMM.
Make a table of values i.e. column without Adapter, column with Adapter.

I assume your #8 means

VCC = 3.3V U2: in=3.19 out=3.06 w/o SD
VCC = 3.3V U2: in=2.28 out=0.97 with SD
VCC = 5.0V U2: in=4.20 out=3.29 w/o SD
VCC = 5.0V U2: in=2.20 out=1.00 with SD

I assume your #8 means

That is correct.

Change the Adapter !

I've been using it actively for a long time. It works fine. Same about the SD card inside. Do you suspect that it might be the culprit?

EDIT:

Measures w/o microSD card are same as with the empty SD slot.

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