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I was just about to hook up an AdaFruit 8x8 LED matrix to the little round board from 4Troniks when they sent me something even better.


The version 0.2 board came with straight headers and an interesting daughter board full of WS2812B compatible LEDs. These are dead easy to code as they all take a common data line and work with the FastLED LED animation library for Arduino.

2016-07-22 16.22.05.jpg 2016-07-22 12.43.36.jpg

The new board is fractionally larger and can be quite tall when stacked up. However I was also given a protoshield which can be soldered in-between the two. I've still to design a badge to host the board so have been playing about with designs in OpenSCAD. I did mange to knock up a quick demo to see the LEDs in action. Perhaps this could be wired to a sound sensor so that the mouth moves when you speak?



#include "FastLED.h" //From FastLED LED animation library for Arduino (formerly FastSPI_LED) 

#define NUM_LEDS 14
#define DATA_PIN 4


void setup() {
  FastLED.addLeds<NEOPIXEL, DATA_PIN>(leds, NUM_LEDS);

void loop() {

void face() {

void eyes() {
  leds[0] = CRGB::Blue;
  leds[2] = CRGB::Blue;

void smile()
  leds[7] = CRGB::Red;
  leds[10] = CRGB::Red;
  leds[11] = CRGB::Red;
  leds[12] = CRGB::Red;
  leds[13] = CRGB::Red;
  leds[8] = CRGB::Black;
  leds[9] = CRGB::Black;

void talk()
  leds[7] = CRGB::Black;
  leds[10] = CRGB::Black;
  leds[8] = CRGB::Red;
  leds[9] = CRGB::Red;
  leds[11] = CRGB::Black;
  leds[12] = CRGB::Red;
  leds[13] = CRGB::Black;

I am a relative newcomer to arduino, but I need to make a display in the house which will tell me how much water is stored in my water tanks (max 15,000 litres) 30 meters from the house, I think the best method would be to use differential pressure and transmit the reading by wi-fi to an LCD screen in the house. Has anyone done this before? Can anyone help?

I've been given a new board from 4tronix to RoadTest, which is compatible with an Arduino UNO but with a significantly different form factor. The board is still in beta so has yet to gain a proper name.


The board is 27mm in diameter about the same size as a£2 coin it has a ATMega328P-AU microcontroller and a CH340G USB interface A blue LED is attached to pin 13 4 digital and 4 analogue pins are broken out along each size with the power connectors top and bottom


On the back of the board is a rechargeable Lithium ION coin cell which 4tronix thought should have a run time of about 1 hour. There is a small power switch so you can turn it off to save the battery or to speed up charging.


My first thought was to see if we could increase that with some power management. So I created the following "sleepyblink" code which flashes the LED for just 100ms before sleeping for 1s. The board uploads quickly, although I did see that the board changed COM port number when I powered it off an on which might cause irritation when programming it.



//Library from
#include "LowPower.h"
int ledPin = 13;                 // LED connected to pin 13
void setup()
  pinMode(ledPin, OUTPUT);      // sets the digital pin as output
  delay(5000);                 // Nice long delay to help with reprogramming    
void loop()
  digitalWrite(ledPin, HIGH);    // sets the LED off
  digitalWrite(ledPin, LOW);   // sets the LED on
  LowPower.powerDown(SLEEP_1S, ADC_OFF, BOD_OFF);


The battery lasted over 33hrs, it stopped over night whilst I was asleep so I know it was less than 41hrs.


Next up is to make a simple badge.

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