esp8266 tft display manufacturer

What you’ll build in less that 20 minutes of soldering is a device, that (with demo sketch for Arduino IDE) is able to connect to your WiFi and fetch current WeatherStation data for pre-defined location. On first start, it will require to calibrate touch display used to control the device.

Even though it might not be visible at first sight, there’s a tremendous amount of work behind this thing (and by ‘thing’ is meant a combination of software and hardware). When you start installing the sample Weather Station sketch, it appears that you need to install some libraries, all of them by Daniel Eichhorn: ESP8266 WeatherStation which is a WeatherUnderground client, Json Streaming Parser that helps keeping low memory profile while getting huge API responses, and Mini Grafx library that implements a VSYNC equivalent through framebuffer for embedded devices.

The Arduino sketch has 438k built so there’s still plenty of room to add more features. However, I’m looking to dive deeply into existing example code in order to reuse as much as possible. There’s NNTP, visual WiFi display, display carousel, icons, fonts, colours and last but not least the touch screen support.

Due to the planned game being more advanced than Space Invaders I needed a processor with more memory and speed than the Arduino could offer. Enter the ESP8266 processors which offer faster speeds and lots and lots more memory. Wifi is also available but will not be required for this project unless we implemented a World High Score Table perhaps! There are newer versions, ESP32, available with even more power but are more expensive and we don’t need that level of performance for this project. I’m using a NodeMCU from Lolin, which is basically a breakout board for the ESP8266 so that you can use it easily on breadboards or small production runs using through hole.

Connections – very careful now!Looking at the back we can see +3v3 (this screen can be powered from 5v as well), several grounds (Gnd) and SCL/SDA. This shouldmean that this device is an I²C device and can be easily connected to our Arduino. Err… Think  again. This screen gave me no end of problems as connecting it to the  I²C connections and running any demo I could find on the internet did not get anything on the display. I went back and looked at the listing for this device, it stated SPI Bus not I²C ! So it began to become apparent that this screen had an SPI interface. SCL and SDA would logically seem to be SPI clock and data (MOSI) respectively but other pin labels didn’t match normal SPI protocol labels. Reading several resources for other different screens and looking at the source code for the examples in the Arduino IDE Examples library lead me to find the correct connections to power and use this screen.

Power is self explanatory. LED adds a little extra brightness to the screen but it does still work if not connected. I’ve seen resistors added in series here and even variable ones to vary the brightness but I’ve ran it directly connected on this screen with no issues and wouldn’t want it dimmer as its not ultra bright. It is actually on even when not connected giving adequate brightness in my opinion. SCL is the SPI clock and goes to the NodeMCU’s hardware SPI pin (pin D5). SDA is actually the SPI MOSI connection and goes to the NodeMCU’s SPI MOSI pin (D7). RS is a Regsiter Select pin for ST7735 driver chips, this maps to a variable called TFT_DC in the Adafruitcode (explained later) that I was using for testing. This controls whether we are sending a command to the ST7735 chip or actual data. I think that Adafruit call it DC meaning Data Control, but I’m not sure. On some boards it may even be referred to as A0. For our purposed we connect it to D4. RST is the screen reset and and is connected to pin D3. These last two can connect to any NodeMCU pins that are not used for other functions. CS is Chip Select (usually referred to as Slave Select in the SPI protocol) and again can connect to any pin but I use D2. If this is pulled low then this device can receive or send data on the SPI bus. If only one device in your design you could pull this low permanently and not use D2.

Driver CodeWhen presented with this board (as mentioned above) it was difficult to work out where wires should go and what driver software I needed for the display. Looking at the solitary chip on the board and Googling revealed nothing. So I went back to the sellers listing and found buried deep in a sub-page description the phrase “7735 drive”. Googling this revealed Adafruit had written some drivers for this chip for a board they had created (which also had an SD card slot on it as well). It was not surprising I didn’t find the 7735 chip on the board as this chip is designed to by embedded onto the back of the screen. It was being armed with this source code and other web pages dealing with different chip sets but similar displays that I managed to work out (with a little trial and error) the connections talked about previously above. Initially I used the Adafruit driver code but gave issues with this screen (as it was designed to work with the one they sell). Look below.

Also when the screen orientation is rotated (in software) so you can write to the display any way up then more things either correct themselves or mess up again.

Fixing the ST7735 driver to work with this screen.So we have some work to do still to make this work well with our display. The driver we have used to get this up and running was not designed for this display exactly. Things appear clipped and off screen. There were other issues with colour (i.e. red was blue and blue was red amongst other colour problems) and other graphics routines were not correct. I won’t bore you with all the tiny re-writes I did but just supply you with the new driver for this particular display. This driver is very specific, i.e. only targeting this display and resolution but it may well work with many other similar displays. At the time of writing I have no other displays to test with but will be expanding the driver code as and when required. The full driver code is available from the link below, add it into your Arduino in the usual manner (Adding libraries to the Arduino IDE.)

Load up the example code that should now be available at “Files->Examples->XTronical ST7735 Library->GraphicsTestESP8266”. This is basically the Adafruit example with just some tiny changes (It goes through all the tests for each rotational position of the screen) so that it uses the new driver file and slightly altered initialisation routine.

The breakout has the TFT display soldered on (it uses a delicate flex-circuit connector) as well as a ultra-low-dropout 3.3V regulator and a 3/5V level shifter so that you can use it with 3.3V or 5V power and TTL control logic.

The TFT display provides a semiconductor switch for each pixel and each pixel is directly controlled by pulse. Therefore, each node is relatively independent and can be continuously controlled, which not only improves the response speed of the display, but also can be accurately controlled. The color level is displayed to make the TFT LCD color more realistic, the brightness is good, the contrast is high, the layering is strong and the color is bright.

The IoD-09 modules feature a full colour 0.9” TFT LCD display. They are powered by the WiFi enabled ESP8266, which offers an array of functionality and options for any Designer / Integrator / User.

This range of modules has been designed to minimise the impact of display related circuitry, and provide a platform suitable for integration into a product.

The IoD-09 modules can act as master or slave devices, they can be effortlessly connected to the internet, can display a raft information and graphics, along with the capability to communicate to SPI, I2C, and/or 1-wire devices, as well as having general GPIO for digital control/input.

Nextion is a Human Machine Interface （HMI） solution combining an onboard processor and memory touch display with Nextion Editor software for HMI GUI project development.

Using the Nextion Editor software, you can quickly develop the HMI GUI by drag-and-drop components (graphics, text, button, slider, etc.) and ASCII text-based instructions for coding how components interact on the display side.

Nextion HMI display connects to peripheral MCU via TTL Serial (5V, TX, RX, GND) to provide event notifications that peripheral MCU can act on, the peripheral MCU can easily update progress, and status back to Nextion display utilizing simple ASCII text-based instructions.

ESP8266 has powerful on-board processing and storage capabilities that allow it to be integrated with the sensors and other application specific devices through its GPIOs with minimal development up-front and minimal loading during run-time.

The breakout has the TFT display soldered on (it uses a delicate flex-circuit connector) as well as a ultra-low-dropout 3.3V regulator and a 3/5V level shifter so that you can use it with 3.3V or 5V power and TTL control logic.

In the previous article (“WiFi OLED Mini Weather Station with ESP8266“) I have used the OLED kit from https://blog.squix.org. And as promised, this time it is about the “ESP8266 WiFi Color Display Kit”:

I had ordered both because I thought that the Color Display kit is needs the other kit as a base. Well, it turned out that both kits work independently. My bad. Actually this is good, as I have now two independent ESP8266 weather stations :-). An addition to that, they can exchange data (e.g. temperature/humidity) with a server, so that makes them a perfect dual weather station.

This time assembling the kit needs basic soldering skills. With the excellent tutorial by Daniel Eichhorn  (https://blog.squix.org/wifi-color-display-kit) this should be a piece of cake. The only consideration is what kind of headers to use. I opted for the ‘larger but flexible’ approach. That way I can separate the boards if needed.

Example code is available on GitHub (https://github.com/squix78/esp8266-weather-station-color). The code is very well documented I had no issues to make all the needed configuration (WiFi SSID and connection settings). After a few  hours I had the ESP8266 weather station up and running in the first prototype of the enclosure:

After a few hours, I have now my second ESP8266 WiFi weather station with touch LCD. It is not looking good and I very much enjoy it. The design is available on Thingiverse (https://www.thingiverse.com/thing:2527282).