In each cycle, the display is automatically cleared before the lambda is executed. Option called lambda: which will be called every time ESPHome wants to re-render the display. So, first a few basics: When setting up a display platform in ESPHome there will be a configuration Please note that this only applies to displays that can control each pixel In this section we will be discussing how to use ESPHome’s display rendering engine from ESPHomeĪnd some basic commands. So when you want to write some text or sensor values to the screen you will be writing in C++ codeīe simple and to be used without programming experienceīut also be flexible enough to work with more complex tasks like displaying an analog clock. To achieve all this flexibility displays tie in directly into ESPHome’s lambda system. Many things like draw some basic shapes, print text with any font you want, or even show images. Text based displays like 7-Segment displays orĭisplays like the Nextion TFT LCD Display that have their own processors for rendering.īinary displays which can toggle ON/OFF any pixel, like E-Paper displays orįor the last type, ESPHome has a powerful rendering engine that can do Fundamentally, there are these types of displays:

We will define our array as a const integer since it will never change, we will need 10 unique arrays to store 0-9 values with 7 positions in each array, one for each segment.The display component houses ESPHome’s powerful rendering and displayĮngine. Multi-dimensional arrays may sound scary if you have never used one, however if you are familiar with basic arrays already then you can think of them simply as an array of arrays. One easy solution is to use something called a truth table, to store our truth table we will need to create a multi-dimensional array. That’s it, pretty simple right! Now how can we do this pragmatically? It’s pretty obvious when you look at the diagram above where the name came from, any digit 0-9 can be shown by activating the right combination of 7 segments.

Lets start by looking at why they call it a 7-segment display. Luckily this display is a lot more capable than the vacuum fluorescent and 7-segment displays of the past, we should be able to overcome this dilemma with some simple code.įirst things first before we can write any code, we first have to understand the basic operation of a 7-segment display. The only problem, I was using a 128×64 OLED driven by a SSD1306 driver.

I had a project come up recently where I needed to display some numbers that looked like an old 7-segment display.

Segment display font