1.8 SPI TFT from ebay - problems

I got a HY-1.8 SPI display board from ebay. I uses a ST7735 chip, so I can use the adafruit ST7735 lib which works in general. I used the graphics demo sketch with hardware SPI.
The issue I have is that the screen background (not the backlight) becomes brighter when data is written. I suspect the CS line to do this because I unplugged the serial data line and still the background gets brighter at the moments of access. Did anyone experience the same problems? Is this an issue with the TFT?


Do you have a link to the actual display?

Perhaps the power supply isn't adequate - measure it with a multimeter whilst driving the display? How have you
connected it all up?

I got this display and been using it for a while. No such problem experienced.
How is you module power configured (there is a jumper when used with 3V3 bypassing the LM1117)? What voltages do you use?
What I see is this module works even when Vcc (pin2) is being disconnected.. :~
The display tft matrix and chip is low power so maybe it is enough to power him via signals (via clamping diodes on its inputs).


the 3.3V jumper is open, I use 5V from the arduino board (which is connected to USB). I connected the backlight via 1K resistor to +5V.

Arduino pin TFT module Pin
8 rst 6 rst
9 dc 7 A0
10 cs 10 cs
11 mosi 8 SDA
13 sclk 9 SCK

Then I used the graphicstest_highspeed example from the Adafruit_ST7735 library.

Sorry, I got no link to the module.


I have a 1.8 SPI TFT also from ebay, but my problem is that I have a 16pin pcb.
Like this:

I have found its datasheet:

Has anyone encountered & used this kind of TFT before?
My problem is that I have tried to follow the instructions from the adafruit tutorial, but I just have more pins that I could figure out on howto connect. Also, I need to use both the TFT display & SD cards, so I have the MISO-MOSI-SCK-SS pins (50-53) reserved. Oh, and I'm using an arduino mega adk r3.

Can anyone help me with the wiring?

Thank You!

I have a 1.8 SPI TFT also from ebay, but my problem is that I have a 16pin pcb.

This is exactly the one I have. You can use the wiring table above.
The mega requires slightly different wiring, because the hardware SPI is on different pins. Just read the comments in the adafruit example sketch, it is explained there.

Can you test the example sketch? Do you experience the same issue than me?


Thanks for your reply, it works rewired!
Here is my wiring with arduino mega:
Mega pin Arduino pin TFT module Pin
8 8 rst 6 rst
9 9 dc 7 A0
10 10 cs 10 cs
51 11 mosi 8 SDA
52 13 sclk 9 SCK

But I have another question: how will my SD card work with this wiring? Since he sd card has a different set of pins (it works with it):
TFT Mega
11 SCK 51 SCK
12 Miso 50 miso
13 Mosi 52 mosi
14 CS 53 SS

So my problem here, is that

  • TFT pins 8 (SDA) and 13 (Mosi) should be connected both to mega pin 52.
  • TFT pins 9 (SCK) and 11 (SCK) should be connected both to mega pin 51

So what to do with this? Should I wire it like this? Or how?

And another thing: should I use the standard SD fat32 library with this TFT? Or any other?

Thanks for your help!


Thanks for your reply, it works rewired!

Youre wellcome!
Does the background flicker?

I dont know how to use the SD card, never tried that. Please open another thread for this.

I run both tft and sdcard. Just connect miso/mosi/sckl in parallel except /cs (so you need a /cs for the sdcard and the second /cs for tft).
Be aware the signals to the sdcard go via 1kohm resistors - this might be an issue with very high speeds (not an issue with arduino, however :slight_smile: ).

By the 1kohm resistors you mean the PCB has them? I know it.

And a dumb question: Ho can I wire paralell the miso/mosi/sck in a prototype board?


I ave this 1.8" tft display too, I got it working already except the sd card, I could not make it work, can anyone provide a working sketch?

this is the tft display I am talking about:

up...someone may know this

I note from the pictures it has some resistors in line with the SPI signals
as makeshift level-shifters - what value are they?

current limiters so that the lcd will not be damaged, I got the idea from sparkfun tutorial in connecting nokia 5110
here’s the video, I made a multipurpose shield for the femtoduino: