Project: SpaceState ESP Clock
Name	SpaceState ESP Clock
Initiator	zeno4ever
Status	60%
Skills	Basic Electronics, Arduino Software (C)
Summary	Show space open/close state with nodeMCU / ESP-12E / ESP8266

I wanted to see if the TkkrLab hackerspace is open on my clock. For this I used an nodeMCU with a RGB led to request the spaceapi every 10 mins and display open (green) or closed (red) status. The nodeMCU is a developer board with an ESP8266 / ESP12-E chip. There are a few different types of nodemcu's, check out this article for more information about these

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Resources

Parts List

• Clock
• nodeMCU v2
• diffuse 10 mm RGB LED
• 1x 1K resistor (you can alter this depending how brite the LED should be)

Software

• source code for nodeMCU : https://github.com/zeno4ever/spacestatus_ESP
• Library for json processing https://bblanchon.github.io/ArduinoJson/
• Arduino IDE for uploading source to nodeMCU

Steps

I used male breadboard connectors to connect everything to the nodeMCU, you can solder the RGB led directly on the wire (with one resistor on the anode (+))

The clock I have has a 6v that is connected to the Vin and GND of the nodeMCU

• Check the clock you want to use if there is enough space inside to put nodeMCU inside and where to place the LED.
• Check if you can use the power of the clock and this is good for Vin. In my case i had 6 V, this in within the range of 4.5V ~ 9V. If you have a other version of nodeMCU check the documentation.
• Download the source and change the settings for your hackerspace.
• Upload code to nodeMCU via USB
• Connect the RGB LED and power in the the nodeMCU

LED remarks

If you order a LED chip check what type you buy, you have commen anode and commen cathode types. These have to be connected different I uses an common anode. I include setting you can change. I have no tested this part so there may more changes needed to make this work.

I also use one resistor since i only show one color all times. If you want to use more then one color at a time then you should use a resistor per color, so 3 for R,G,B.

You can cut a part of the LED as long you dont touch the parts where the electroncs are. For me I 'decapped' the LED with a iron saw and sanding it down to have a flat surface.