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 http://www.rocketscream.com/blog/2011/07/04/lightweight-low-power-arduino-library/#sthash.PhJ0PF9f.dpuf
#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.