Uptime robot-robot

So.. 3 years with no posts .. wow..


My better half works with web sites and hosting. They rely on the service of UptimeRobot to notify them if any of their sites is down.

I though it would be fun, to create something physical, that could maybe blink or something.

Introducing.. The UptimeTimeRobot-robotstill working on the name ūüėČ

When the “robot” is connected to wifi, it will just sit there and blink every once in a while.

But whenever a server is down, we get this.

At the top, there’s a button to pause the alert until next cycle, where it calls the uptime robot api.

Click: Pause the alert until next cycle.
5 sec. press: Reset wifi settings.
10 sec. press: Checks for new firmware OTA

The body is 3d printed, and the interior is
– 1 x 5110 lcd display
– 1 x wemos d1
– 1 x push button
– 2 x leds (red and blue)

And here’s how it’s wired together:

Source code can be found here: https://github.com/kim82/esp8266UptimeRobot

Homebridge with Sonoff


I bought two of those cheap wifi remote controlled switches called Sonoff.
These switches allow you to turn them on and off with an app on your phone.

Inside these switches are a ESP8266 , which means that we can flash the chip with our own custom firmware.
And with the help of a Raspberry pi we can enable homekit.

Firstly I reflashed the sonoff with my custom firmware, using the Arduino IDE. (Google how to flash ESP8266)
(This disables the use of the official sonoff app)


Remember to change the hostname, if you have multiple sonoff.

#define HOSTNAME        "sonoff_00"

Raspberry Pi – Homebridge

Download and install Raspbian on the Raspberry Pi.

When this is done we can install Homebridge, which is the service that sits between your apple devices and the sonoff switch.

The full install guide can be found here:

TLDR; (Raspberry Pi 3)

sudo apt-get update
sudo apt-get upgrade
sudo apt-get install git make
sudo apt-get install g++
#install node
curl -sL https://deb.nodesource.com/setup_8.x | sudo -E bash -
sudo apt-get install -y nodejs
#install Avahi and other dependencies
sudo apt-get install libavahi-compat-libdnssd-dev


Next we need to install Script2, which is a homebridge plugin that allows you to run bash-scripts though the homebridge

npm install -g homebridge-script2

Start at bootup

Lastly we need to start Homebridge whenever the Raspberry pi boots up.
And the following method was found here:

We need to create the following two files.


# Defaults / Configuration options for homebridge
# The following settings tells homebridge where to find the config.json file and where to persist the data (i.e. pairing and others)
HOMEBRIDGE_OPTS=-U /var/lib/homebridge


Description=Node.js HomeKit Server 
After=syslog.target network-online.target


#could be /usr/local/bin/homebridge - check where the homebridge folder exists

ExecStart=/usr/bin/homebridge $HOMEBRIDGE_OPTS


And to enable the newly created service. (first time only)

sudo systemctl daemon-reload
sudo systemctl enable homebridge
sudo systemctl start homebridge

We also need to create a new user and the folder for the config.json file

#create a new user
sudo useradd -M --system homebridge

#creates a new folder
sudo mkdir /var/lib/homebridge

#changes the owner of the folder to new homebridge-user
sudo chown homebridge:homebridge /var/lib/homebridge


To configure the script2, we need to create a config.json file in the /var/lib/homebridge folder.

Mine looks like this:

    "bridge": {
        "name": "Sonoff",
        "username": "AA:BB:CC:DD:EE:FF", (THIS NEEDS TO BE CHANGED)
        "port": 40500,

    "description": "Sonoff Homebridge",

    "accessories": [
                    "accessory": "Script2",
                    "name": "Bedroom lamp",
                    "on": "curl http://sonoff_00.local/on",
                    "off": "curl http://sonoff_00.local/off",
                    "state": "curl --max-time 1 http://sonoff_00.local",
                    "fileState": "",
                    "on_value": "on"
                    "accessory": "Script2",
                    "name": "Living room lamp",
                    "on": "curl http://sonoff_01.local/on",
                    "off": "curl http://sonoff_01.local/off",
                    "state": "curl --max-time 1 http://sonoff_01.local",
                    "fileState": "",
                    "on_value": "on"

    "platforms": []

Restart the homebridge service

sudo systemctl restart homebridge

Now you should be able to add the sonoff homebridge to your Home-app on the iphone/ipad, and control the switches.

GIF frame – IOS app

My first idea was to add a ESP8266 to the GIF frame, so that I could control it remotely. But I haven’t had much success when tinkering the it. I can not get it to run a webserver without it freezing up.

But I had a Bluetooth Low Energy (BLE) laying around – Yes, I have a lot a stuff laying around ūüôā
I had bought it a while ago, but didn’t really got into code in Cocoa Touch for iOS- also I didn’t want to pay 100$ for the developer subscription – which was needed for you to get the app on the iPhone.

But with the latest release of xcode, you can install your own apps on your iPhone without the subscription! So everything kinda came together for this project ūüôā

The BLE device communicates with a serial port, and can talk directly to the Arduino.
I just need some small adjustments to the menu code – adding software serial. (and I included a power on/off option, while I was at it)

Download: GIF frame

And here it is:

GIF frame – software

The software for the animated gif frame, consist of 3 parts.

  1. code for the Arduino, that reads the sd-card and displays it on the ledstrips (main board)
  2. code for the Arduino, that runs the LCD menu (menu)
  3. code on the PC, which converts a GIF into a text file, with the color codes of the GIF.

Arduino sketch

The two Arduinos communicates via the serial ports.
At startup the main board, request the menu for the current settings. (it does this by sending a request_signal)

Serial.write(REQUEST_DATA);       // request for new data    - value is 155

The menu, then sends the settings in the following format

Serial.write(START_SIGNAL);       // 111
Serial.write(loadNext ? 1 : 0);   // next                    - values 0 or 1
Serial.write(menu.mode);          // mode (single/slideshow) - values 0 or 1
Serial.write(menu.repeat);        // slideshow duration      - values 1 to 50
Serial.write(menu.speed);         // speed                   - values 10 to 100
Serial.write(menu.brightness);    // brightness              - values 10 to 60
Serial.write(END_SIGNAL);         // 222

Whenever a change in the menu happens, it will also send this byte array to the main board.
The menu also,saves the changes to EPROM, so that the settings can be restored when power off and on.

Download the sketch + xcode here: GIF frame

PC software

On the PC side, I used this Processing sketch, but I think i really is just Java. Kinda like Arduino sketch is C/C++.

I modified the original code, so I only outputs the color codes, and not the Arduino sketch code.
Here is my version: GIF_Converter.pde