NodeESP

The door today reveals the counterpart to yesterday’s component, namely an IR diode. Now you can build a real remote-control for your TV and control it conveniently via smartphone and website. We will use the following setup. Setup of remote controls with IR receiver and transmitter diode Select the program for today. The board will start again in headless mode; the board’s website will not be available but you will have the board’s MQTT feature. To switch to default mode, remove the jumper on pin 23 and restart the board. ...

The door reveals a very special component today, namely an infrared receiver module. You can use it to 15. Tag receive customary infrared remote-control signals. We will use the following setup. This is how you properly connect the IR module to the board After the circuit is set up, select today’s program. Please note that you will not be able to reach the board’s website, because it is deactivated for our experiment today. The board works now in headless mode and has no visible interface. If you want to run the website again to activate other programs, for example, you only have to pull out the jumper from pin 23 and restart the board. Everything will run as usual. ...

The door of day 14 reveals another LED. Now we have two LEDs with resistors and two buttons and 14. Tag cables, enough to build a complex lighting system. We will use the following setup: Setup with four loose cables (yellow) as touch buttons Enable today’s program and install today’s flow. Don’t forget, replace [PID] with your personal ID and the easiest way is using the trick with the Editor. ...

Today we will find again a 1 kOhm resistor hidden behind the door of the Advent calendar. But we are not going to use it today. Instead I would like to show you how you can build a smart touch switch. We will use a simple setup that is made up of four loose hanging wires as touch buttons and a wire jumper to pin 23. Four yellow wires serving as touch buttons Our experiment today is special for its program, which you should activate now on the configuration page. Once enabled, you will notice that the status LED flashes briefly and then turns off, because the board is again running in the power-saving deep-sleep mode. It will not wake up after certain time however. It will wake up only, when you touch one of the touch buttons. The board then sends information via the touch button to the broker who triggered the wakeup. It will look something like this: ...

Today we will find again a button hidden behind the door of the Advent calendar. In our experiment today we will continue to cover the MQTT protocol, but this time in conjunction with Node-RED. We will also learn how two buttons can be evaluated simultaneously. The experiment today is structured as follows: Setup with two buttons So now we have two buttons that we can use. We activate the program for today. Then we import the Node-RED flow. You need to adapt it slightly by replacing [PID] in the topic with your personal MQTT ID. That’s pretty easy if you use this trick: ...

There is a cable set again hidden behind the door today. We will need it in the next few days when the setups become more complex. Over the past few days we have sent most of our data via UDP. This protocol is very convenient; on the one hand it has a small overhead (data is sent in addition to the actual application data) and on the other hand, it is a broadcasting system and can thus send data to several devices simultaneously. But today we will learn about a second protocol that plays a major role in IoT. This is the message protocol MQTT (Message Queue Telemetry Transport) and it was specifically developed for machine-to-machine communication (M2M). The reason that this is such a brilliant protocol is due to its compactness and simplicity when it comes to exchanging data between devices such as control data, measurement data or text. Compared to HTTP, the overhead is very small. That is why embedded devices such as microcontrollers like our NodeESP can process the data well. ...

There is a battery compartment for three A batteries (4.5 V) hidden behind the door today that will 10. Tag power the board independently of a power outlet. For economical battery operation, we have the deepsleep mode. This mode allows the board to go into a deep sleep where it uses almost no power at all. After a certain time, the board wakes up, performs a modest task and goes back to sleep shortly after. In this mode a lot of energy is saved due to the long sleep and short wake times and ultimately the batteries will supply power to the board for months. The setup we will use today includes again the light sensor and it gets a wire jumper that connects pin 23 and GND. ...

There is a photo transistor hidden behind the door today. We will use it to measure the ambient brightness. The potentiometer is in series with the phototransistor potentiometer in our circuit and you will be able to change the sensor sensitivity with the potentiometer. In this circuit the reading value will increase when dimming the sensor. Todays Circuit You will see this happening today in our user interface within the gauge element. But again, you first import and start today’s flow in your Node-RED environment and of course, you have to disable the one from yesterday. Also, do not forget to enable today’s program on the configuration page and adjust the IP of the UDP send node. ...

Breadboard Construction On the eighth day you will find a potentiometer behind the door. We are going to use it as voltage divider. You can set a voltage between 0 V and 3.3 V, which is measured by the board and sent to NodeRED. On top of to the functions of yesterday’s stairway light, you can also send the measured values. The Flow of Today External content from pastebin.com Loading it sends data such as your IP address to pastebin.com. Privacy Load content open directly ↗ As usual you can obtain today’s flow from here. Don’t forget to disable yesterday’s flow and you may need to adjust the send-IP. The flow of today also has a new node for the dashboard, namely a gauge to visually display the measured value. ...

There is a red LED hidden behind the door today. We are going to use this to build a simple stairway light with web interface. We will thus build the following circuit and, of course, activate today’s program. Breadboard Construction (short LED pin is up) Locate the Node-RED flow below and import. Deactivate yesterday’s flow after the import to make sure the UDP receive nodes do not get in your way. This time the flow also has a send node besides the receiving node. You may need to adapt the send node to reflect your broadcast IP. A message that arrives at the UDP will be converted back to a JSON object by means of a JSON string, which is pure text. The difference here is that you can now access also individual attributes. ...