We have a remote LCD Node that works on NodeMCU board. It has a 40×4 char LCD attached to it and displays text received via a network message. We also can use Raspberry Pi as a remote LCD. But all those LCDs are small. We need something bigger and we have it! This something is an ILI9325 graphical display. There is a huge difference between char and graphic but we can simulate char interface. Our GfxLCD library has an ability to display a text and with a little bit of tinkering, it should work :D.
This could bring nice results, imagine a dump from Symfony with multiline formatting thanks to the ProxyLCD project. Nice 🙂
Last part was strange, we wrote a direct driver that has no real usage. We done it only because we kept compatibility. This time we will do something more useful, WiFi content driver. We will try and do in such way that only content is send. This is more friendly for network and sanity 😛
What does it mean? It means that we will add another driver to CharLCD. This will allow us to use remote LCD with Raspberry Pi and later with any application in Python. It should be possible to use it with LCD Manager package and this is something very interesting 🙂
As a remote LCD we will use HD44780 (40×4) hooked to NodeMCU via i2c (but we know that we can plug any LCD via gpio or i2c 😛 ) and it will listen to broadcast messages.
Rpi (with CharLCD and driver) will broadcast UDP messages into network.
Time to take another step with NodeMCU and HD44780. This time we will separate driver logic from lcd logic. Why? Because it is much more flexible for our lcd (direct and bffered) to have general write, set_xy and move wiring specific logic to driver. This way we can just swap gpio with i2c without any problems.
This imply that we will also write i2c driver 🙂
Another matter is hooking screens with size 40×4. In fact they are two smaller lcds, 40×2, with shared all signals except E1 and E2. How it works? You set required signals and select top screen with E1 or bottom with E2.
Lets get to work.
Code is available in boilerplate (more…)
Our module displays strings as soon as function write is called. It is mostly enough but sometimes it is better to prepare what we want to display and then display it. Such action uses buffer and that why I’m calling this buffered mode.
We made something like this in CharLCD so we can convert idea to NodeMCU. Due to LUA characteristic both modes are combined into one module.
We played a little with lcd and we know that it works 🙂 It is a good idea to create a class that can be used in any project. Such class must allow setting width, height and pins if they are different from default one. It’s behaviour is based on lcd direct from CharLCD python class.
That means it is gonna display chars directly without buffer.
Another post about ESP8266!. This time we will attach a char display based on HD44780, something we already done for Raspberry Pi.
It will require some wiring and writing.
This time I’m also using NodeMCU v3 board because it has 5V on VU pin and we gonna power our display from it.
As for the display I have a nice 16×2 lcd.
What I need is ability to read content of LCDs via network. With our manager it should be easy. We will add such service to Display class. It will start server and react according to request. For now I think about two commands, one for getting list of all managers and second for getting a content from needed.
In this article we will work on views and create our first view for home tab. We could put all code into one file but it would be a mess. So lets take a different approach, we will create a separate file for each view. Next we will work on button widget and create quit game action. Don’t forget that Piader is a tool to improve LCDManager.