16 X 16 Pixel RGB LED Artboard Part 3

This is the third post in the 16 X 16 Pixel RGB LED Artboard project, Part1 and Part2  links just in case you showed up late!

In this post I will discuss the building of a pine framed box to house the pixel array. It has a glass cover on the front for easy cleaning and finished look.

First part was cutting the frame pieces, used a miter box and hand saw to cut all four sides.

Frame of pine

Next I carved out a groove for the glass, the location of the grooves was marked onto the wood with a pencil, square and metal ruler.

Then I used a small 1/4″ wood chisel to slowly carve out the groove to a depth of approximately 1/4″ deep. The glass was cut 1/2″ (13mm) larger on both sides than the wood frame. So a groove about 3/16″ to 1/4″ holds the glass in place and hides the edge.

Laying out the grooves
Cutting the grooves
Fitting the glass

Ok so that went fairly quickly, it was a lot of fun carving the wood. I love the smell of fresh cut wood.

Once I was totally satisfied with the fit, wood glue was applied to each joint and painters tape used to hold the sides in tension with each other.

Holding the frame together while glue dries

The panel is held in place with offcuts from making the sides.

Completed frame with led array in place

Right away I tested it out!!

Very first full panel tests!!

And the first tests were successful!

This panel is power hunnngggry though!! The small bench power supply I used for this test immediately started to smell like burning electronics, so I shut it down… Need to find a 5V 4A power supply, 10A would be even better!

The pattern shown on the panel  is being fed via wifi to an ESP8266 mounted on the back of the panel. The ESP8266 is running an Artnet Node with two universes. I’m feeding the data from a windows PC running Jinx…. ive also tested it with GLEDiator as well and it works fine.

To be continued…. Programming, ESP8266, Artnet in the next post.

16 X 16 Pixel RGB LED Artboard Part 2

So continuing from Part 1 of the Series on designing and building a 16 X 16 RGB LED Artboard...

At first, I had such grandiose ideas of this stunning foam core frame for the LED panel… well this didn’t work out for me. Let me explain why.

Have you ever tried to cut intricate foam core shapes with an exacto knife… the foam either gummed up the blade resulting in horrible edges that basically ended up pulling and ripping that paper backings on both sides…

Grid design for holding WS2812B RGB LED’sI tried multiple techniques and decided life was too short, plus I have a 3D printer at my disposal!! ….. 

Look it just wasn’t my thing. So instead I went with a 3D printed design. Now I could make precise squares, with thin walls. And I could make the exact shape of the LED as  cut out and pop the suckers in…. it all made sense now and I began to come up with printable design…

With this design the LEDS simply “snap” into place on the side opposing the open face of the array.

Here’s a shot of the first piece being printed on my FDM printer:

Populating the first panel with LED’s:

Laying down copper:

Testing the first panel:

Four panels tested and ready for final connections:

After wiring all four panels together, tested finished 16 X 16 panel using Arduino Duemilanove and a 5V 4A power supply 😀

Conclusion of Series in part 3 – Programming and Finishing in Wood/Glass Frame

Wifi Temperature Sensor (ESP8266 + DHT11 + MQTT)

So on cold tuesday night in late December I thought this would be a good evening project – take a nodemcu esp8266 development board from ebay, a dht11 temperature sensor and make a wifi temperture sensor that will publish MQTT messages to my local network.

Seems easy enough… Heres my code for the ESP board:

#include <PubSubClient.h>
#include <ESP8266mDNS.h>
#include <WiFiUdp.h>
#include <ArduinoOTA.h>
#include <DHT11.h>

// Update these with values suitable for your network.

const char* ssid = "SSID";
const char* password = "PASSWORD";
const char* mqtt_server = "";
const char* brokerusername = "openhabian";
const char* brokerpassword = "openhabian";

IPAddress ip(192, 168, 0, 112); // where xx is the desired IP Address
IPAddress gateway(192, 168, 0, 1); // set gateway to match your network
IPAddress subnet(255, 255, 255, 0); // set subnet mask to match your network

WiFiClient espClient;
PubSubClient client(espClient);
long lastMsg = 0;
char msg[50];
int value = 0;

//dht11 stuff
const int pin=D0;
int err;
float temp, humi;
char Temperature[10];

DHT11 dht11(pin); 

void setup_wifi() {

  // We start by connecting to a WiFi network
  Serial.print("Connecting to ");

  WiFi.config(ip, gateway, subnet);

  WiFi.begin(ssid, password);

  while (WiFi.status() != WL_CONNECTED) {


  Serial.println("WiFi connected");
  Serial.println("IP address: ");

void callback(char* topic, byte* payload, unsigned int length) {
  Serial.print("Message arrived [");
  Serial.print("] ");
  for (int i = 0; i < length; i++) {

  // Switch on the LED if an 1 was received as first character
  if ((char)payload[0] == '0') {
    digitalWrite(BUILTIN_LED, LOW);   // Turn the LED on (Note that LOW is the voltage level
    // but actually the LED is on; this is because
    // it is acive low on the ESP-01)
  } else { }

if ((char)payload[0] == '1') {
    digitalWrite(BUILTIN_LED, HIGH);   // Turn the LED on (Note that LOW is the voltage level


void reconnect() {
  // Loop until we're reconnected
  while (!client.connected()) {
    Serial.print("Attempting MQTT connection...");
    // Create a random client ID
    String clientId = "ESP8266Client-";
    clientId += String(random(0xffff), HEX);
    // Attempt to connect
    if (client.connect(clientId.c_str(), brokerusername, brokerpassword)) {
    } else {
      Serial.print("failed, rc=");
      Serial.println(" try again in 5 seconds");
      // Wait 5 seconds before retrying

void setup() {
  client.setServer(mqtt_server, 1883);

  ArduinoOTA.onStart([]() {
  ArduinoOTA.onEnd([]() {
  ArduinoOTA.onProgress([](unsigned int progress, unsigned int total) {
    Serial.printf("Progress: %u%%\r", (progress / (total / 100)));
  ArduinoOTA.onError([](ota_error_t error) {
    Serial.printf("Error[%u]: ", error);
    if (error == OTA_AUTH_ERROR) Serial.println("Auth Failed");
    else if (error == OTA_BEGIN_ERROR) Serial.println("Begin Failed");
    else if (error == OTA_CONNECT_ERROR) Serial.println("Connect Failed");
    else if (error == OTA_RECEIVE_ERROR) Serial.println("Receive Failed");
    else if (error == OTA_END_ERROR) Serial.println("End Failed");

void loop() {

  if (!client.connected()) {

if((err=dht11.read(humi, temp))==0)
delay(DHT11_RETRY_DELAY); //delay for reread


client.publish("apartment/livingroom/temp/state", Temperature);




It works perfect! Currently its set to publish the measured temp to an MQTT topic (in my case apartment/livingroom/temp/state) every ten seconds. My openhab server listens for any MQTT messages and displays the temperature on a webpage.

I plan on using these little sensors to report the temps to my home automation system so it can adjust the heating or cooling automatically.

Finished sensor with 3d printed case, plugs into standard micro usb phone charger. Only needs power all data is sent over wifi, so no usb data connection is required.

3D object files for case here: https://www.thingiverse.com/thing:1128026