Hello,
I am having some problems making the SD card work on a 2.4’ TFT display.
I am using an Arduino Pro Mini 5V. After a few failed attempts I decided to check if the Pro Mini works and I connected it to a Catalex Micro SD card adapter and it worked great. The card adapter works at 5V.
I am using the Datalogger example code from Arduino with the line
const int chipSelect = 4;
changed to
const int chipSelect = 10;
So the problem is not the code or the Pro Mini. I am probably making a mistake wiring the SD card module on the display. I should add that I got the display working and printing lines of text.
The display is connected to the Arduino via a 4050 buffer powered at 3.3V
I connected the SD card pins on the display (SD_MOSI, SD_MISO, SD_SCK) to the display MOSI, MISO, SCK. So they are connected to the Arduino trough the 4050 buffer. The SD_CS was connected to Pin10 also trough the 4050 buffer. It does not work.
I found a topic on the forum:
https://forum.arduino.cc/index.php?topic=354873.0
In the #5 post there are 2 photos that show a display wired in a way that bypasses the SD card resistors. In the post #29 the same user says that he ran some tests and the SD card does not work with the resistors.
I tried with the resistors bypassed and it did not work.
To make things even more confusing it looks like I have 2 different displays. In the link below the one above has 1K SD resistors and the one below has 10K resistors.
https://postimg.org/image/4gbcpxjal/
I only tried using the SD card with the display that has 10K resistors. Both work the same while displaying text and both have the same pins.
My questions are:
- How should I wire the SD card to the Arduino? Directly to the pins or trough the 4050 buffer? VCC will be at 3.3V
- Does anyone know why the 2 displays have resistors with 2 different values? 1K and 10K.
- Should I focus on a wiring that bypasses the SD card resistors?
- Do I have to add other libraries besides the SD library to make it work? The end goal is to have the display and SD card working together but for now I want to get the SD card part working. That’s why I am using a simple example from Arduino.
- Does the fact that I use a MicroSD card with an SD adapter create any problems? It’s the same MicroSD card used with the Catalex adapter mentioned at the beginning of the post.