Proxy LCD

ProxyLCD upgrades and content formatters

To use our beautiful ILi9325 display with ProxyLCD we need to manually edit settings.ini. This is not a good way:) Why is that? Because we cannot set a proper size. We are using a selector with predefined values. We need to change it to two text fields.

And we need theย formatters, what is that you may ask? You shall see ๐Ÿ™‚


ProxyLCD and graphical LCDs with HD44780 driver

Last time we wrote an HD44780 driver that takes GfxLCD compatible display and works with CharLCD package. This is nice because we can use big ILI9486 as a character display.

You may ask, why?
Because with ProxyLCD we can see a big output from Symfony ๐Ÿ™‚ And because we can ๐Ÿ™‚
Today we will focus on two bugs from a previous part and we will see if all chipsets can work with HD44780 driver.

Part 1


ProxyLCD – upgrades in Symfony bundle

I need to focus on my additional project in PHP. That means Doton and GfxLCD lib must wait but we will use this time to upgrade ProxyLCD project.

What is ProxyLCD? It is remote LCD that works on NodeMCU, stand alone desktop app in Python and Symfony’s bundle.
Bundle listens to dump() command and when a dump is called it parse object or array to a string, connects to an app and sends it. App gets this content and sends it to added remote LCDs.

Read more about ProxyLCD on the right column:)


Little tweaks in ProxyLCD

I found one annoying issue – when sending only number it crashes.

Crash was easy to fix but unexpected. While converting int to json, Python just convert it to number. I’m not sure if this is a bug or not. But I added additional check.

Lets make an app a little more talkative. When started it prints some useful info:

Config loaded. Starting app
TCP port:  5054
Broadcast IP:
Broadcast port:  5053
Name       | Node name  | Size    | Stream | Type
Debug      | node-40x4  | 40,4    | +      | charlcd
Info       | rpi1       | 20,4    | +      | charlcd
damaged    | node-2     | 16,2    | -      | charlcd

Symfony ProxyLCD bundle

Finally 3rd phase of project – integration with Symfony ๐Ÿ™‚ But I’m afraid it is not the last part ๐Ÿ™‚

What is the goal of this Symfony bundle? It will hook to dump() command and send content to ProxyLCD application. It will transform any array or object to string representation.
Source on GitHub
Install via composer, package name: kosci/proxy-lcd-bundle


Proxy LCD – desktop application

In first part we saw a summary (hardware and software) of remote LCD. Such remote LCD works on NodeMCU and can be accessed via network. It was first stage of bigger project.
Now is time for second part, a desktop application. Its main task is to manage remote LCDs and provide a way to send content from computer to display.
One may add/remove node and set a stream option. What is stream option?
App works in two ways (one for now :P, second option in 3rd phase) if it receive content and it is not a proper packet it iterates over all added lcds and streams data to them. Difference between display and stream is that stream as name says is just a data stream and it send chars one after another. When it reaches end of available space on display it starts over.
In case of packet it will send formatted content to node.

Get from GitHub

Part 1 – remote LCD

CLI on Raspberry Pi