see the previous posts Wireless Challenge .... the other bit -2 Wireless Challenge .... the other bit Beyond the Phone - eLIST progress 3  eLIST progress 2 , eLIST progress , eLIST - KOBO Touch , 5W Load Schematic


In my last post I was using was using off the shelf Wireless Charging Receivers.

While these aren't using Wurth's coils (sorry Simon), they are using TI's BQ51013A or B chips.



This one is hard to see as the sticky label/cover has removed part of the colouring on the IC.




As you can tell they simply change the tail to suit either a wired or Micro USB



The nice bit about both of these is the various options for where to take the 5v from. In some applications it may be more suitable to use the side.




Adafruit version.



Interestingly in all three of these units, the business end is on a film style PCB, and as far as I can see isn't 4 layers.

It's definitely flexible, unlike the ferrite material which has masses of cracks.




While I was ordering I brought a 1200mA LiPo

The battery is thinner than the one shown in the previous post, and of course contains protection.


and a suitable charger

The charger is default at 100mA, but you solder a jumper and it gives you 500mA



The charger includes two LEDs which show red when charging and green when completed.


I'm currently reconfiguring my layout to make these visible through the opaque disc.







The Item

In the previous post I had eluded to this mystery device, that you couldn't just buy.

Part of that mystery was trying to photograph it, since I needed daylight and some room.



Luckily today worked out fine and dry, and after a quick mounting onto a suitable fixture.


It's an illuminated Beer Tap.



Normally these have a small lamp inside the disc.



Two wires run down the neck and they are powered.


The opaque discs are larger than the ring and need to be persuaded into it. I was lucky they hadn't become fragile, but I imagine they would.

Getting the discs out is not a 5 min job, so replacing the lamp can't be a favorite job





In NZ we like our beer cold, and the better bars even chill the glasses ..they don't like you when you hand it back due to the glass being hot from coming out the sterilizer.

The Tap contains a refrigerant pipe loop and in most bars the entire neck is frozen, this ensures the beer is cold when it hits the glass.

This would not help when you wanted to swap lamps.






I've had the ATtiny85 running the neopixel ring, and its BRIGHT.

The code is simple

#include <Adafruit_NeoPixel.h>

#define PIN 2
int val =0;

// Parameter 1 = number of pixels in strip
// Parameter 2 = Arduino pin number (most are valid)
// Parameter 3 = pixel type flags, add together as needed:
//   NEO_KHZ800  800 KHz bitstream (most NeoPixel products w/WS2812 LEDs)
//   NEO_KHZ400  400 KHz (classic 'v1' (not v2) FLORA pixels, WS2811 drivers)
//   NEO_GRB     Pixels are wired for GRB bitstream (most NeoPixel products)
//   NEO_RGB     Pixels are wired for RGB bitstream (v1 FLORA pixels, not v2)
Adafruit_NeoPixel strip = Adafruit_NeoPixel(12, PIN, NEO_GRB + NEO_KHZ800);

// IMPORTANT: To reduce NeoPixel burnout risk, add 1000 uF capacitor across
// pixel power leads, add 300 - 500 Ohm resistor on first pixel's data input
// and minimize distance between Arduino and first pixel.  Avoid connecting
// on a live circuit...if you must, connect GND first.

void setup() {
  strip.begin();; // Initialize all pixels to 'off'

void loop() {
  // Some example procedures showing how to display to the pixels:

  for (int i=0; i<11; i++)
     strip.setPixelColor(i, 255, 255, 255);  //white;



While I was playing I added a pot to control the brightness.


      int val = analogRead(0);     
      val = map(val, 0, 1023, 0, 255);   // AnalogRead is between 0 and 1023, we need to set it between the 0 and 255

  for (int i=0; i<11; i++)
     strip.setPixelColor(i, 255, 255, 255);  //white;


Line11 allows the entire string brightness to be set, and makes it easier to see once you look away.



At this point I'm working on sleep modes, and reducing the standby to a few uA

Nick Gammon has a very detailed blog which explains it all, and it should be possible to get to 500nA standby.

Electronics : Microprocessors : Interrupts


Because I'm using the Digispark and the extra library, I'm having trouble waking it up, so more work is required.

This may be because of the usb arrangement they have where some pins are held using pullups, or the IDE and how it interacts, but it isn't waking so that's a problem.


However now that I have a freestanding tap, I can remove the lamp holder and metal stand, and set about determining how bright it needs to be.

I'm also undecided if I should have it plain white or do some color.





The neopixels offer some very interesting pattern options, along with changing the whole ring's color.

One of the problems with the color changing is how to control it, what color suits, and under what lighting conditions.

I also have a product label to attach when I'm complete, so it has to fit with that.


I had thought of adding a receiver and using this


So I have some code searching to see if its possible.


I have already decided that a hall effect switch will allow it to be turned on/off using a magnet .... otherwise I still have two wires coming down the neck.





If it doesn't work out, I need to connect the tap, talk to my friendly beer Rep about supply and drown my sorrows .... so either way it's a win win situation.