fritzing tft lcd made in china

Because its a mass product made to the lowest possible cost ( but still excellent in measuring performance ), there is NO WAY to access the digital mesured data and to exploit it differently then showing on the ( mostly poor and cheap and far from the eyes ) LCD of the original bathroom scale.

This is little bit frustrating if you desire to modify the scale design ( I like so much the mechanical column scale design ), improve the poor cheap LCD and place it remote from the scale glass plate, on the wall at eyes level. Also with extracting the measuring data, modifying how the scale behaves or adding connectivity to your smartphone ( WiFi, Bluetooth, IoT ) is then possible.

Operation :Press the TEST switch, Q1 is conducting, feeding VIN to the Nano. The Software is then activating Q2 to maintain Power ON until the measurements are made. ( Soft Power OFF ). Measurement via the HX711 module, with the 4 Load sensors mounted in a Wheatstone bridge. The Measured Value is displayed on the 2.4 Serial TFT LCD. After 10 sec., the UNO make an AUTO Shut Down by blocking Q2. This preserves the 9V Battery.

The enclosure contains the Nano, the 9V Battery, the Serial TFT Display, the TEST Button and the Auto Power OFF logic. The HX711 module stays under the Scale Glass plate.

Sometimes it is handy to have a small screen in your Arduino project. The 0.96 inch IPS color diplay is perfect for this. You can get the original Adafruit Color TFT display with SD card readerfor this for $20 (excluding shipping costs), but you can also find a clone on Chinese reseller websites or eBay. Mine did not include a SD card reader, but it was $3 (including shipping).

To make your project better to understand, you can also add board diagrams. This can be done using Fritzing. Just download the version supported by your OS. I have used the Windows 64-bit version and just needed to unzip it and start Fritzing.exe.

In my case I also needed a part that was not in the Fritzing database. Luckily there is a community that submits parts. It is located on the forum page.  Adafruit also has parts on their Github page. To import the part just click the icon in the Parts frame and select Import...

I was now able to create the breadboard diagram. Below you see the breadboard diagram created with Fritzing app of how to connect the display to Arduino Nano.

The display part is Adafruit based, but I have created a table on how to translate the Original Adafruit 0.96" 160x80 Color TFT Display to Chinese Clone IPS 0.96 inch 7P SPI ST7735 module

Finally, I ended up choosing a 2.2" 18-bit color TFT LCD display that was branded and transplanted onto a breakout board by Adafruit. It"s fairly large and has decently robust graphical rendering capabilities for it"s price, although it was somewhat overkill for this project.

I changed the Adafruit libraries for TFT: GFX , TFTLCD and TouchScreen. I join all in this one library, the library SPFD5408, to avoid problems with duplicate libraries and enables also have the original library Adafruit ready for use in other projects with another TFT hardware.

The next step in the Nextion Editor is to export the TFT file to the micro SD card. Click on File in the main menu and select TFT file output. Now you choose your FAT32 formatted micro SD card and export the file to the card. If you wish, you could check if the TFT file is on the SD card.

You can download every file I use in this example with the following download button. You download a zip file that includes the Nextion Editor TFT file, the used fonts, a picture and the Arduino script.

Now every site and component is set up and you can test if everything is working with the debug function of the Nextion Editor. After everything is working you can compile the project and export the TFT file to the micro SD card.

The next task is to connect the display with your microcontroller and all other components. I use my Arduino Uno as microcontroller, the DHT11 sensor module to measure the temperature and humidity as well as the 7 color flash LED (KY-034) as light. The following fritzing picture shows how to connect all the devices.

I did not buy it at that place, but mine looks the same, and the price was similar. I think it was called Sainsmart ..... They are available from many vendors. I just ordered a larger one for comparison and solving the dependencies of pysical resolution of the LCD vs. logical view at the controller interface.

My first approach was an Arduino Mega and a prebuild interface board. The UTFT Arduino library worked, but the interface board was lousy. I had to do so much rework on that board, that at the end it looked like a warfield.

The general Project: I want to set-up a battery operated info-device, which will be activated by an PIR sensor. Since the standby current of the Arduino board is pretty high, I had to switch it off. So I made a little extra board with an ATTiny, the PIR sensor and a PMOS transistor to switch the power. It worked, and had a standby current of about 150 µA, most of that consumed by the PIR Sensor, but it looked not nice. With PyBoard"s low standby current and fast wake-up times, that all can be combined in a single unit. And, since PyBoard runs at 3.3 V, I just have one power level, compared to the 5V and 3.3 V with the Arduino, even if the TFT has to be switched off for power saving. And the SD card is faster. And ...... I may add an ESP8266 for showing a web page too. I have a handfull of them in my drawer. But thats at the far end. Mechanical design comes first.