Those who (jokingly) complain that their wallets empty out every time they read my blog will be in heaven today… backlit and non-back-lit touch switches for as little as FIFTEEN PENCE !!! It’s a winner!
Could these be the world’s cheapest backlit touch-switches? (Updated September 07 2017)
There aren’t any catches here – you can buy one at a time for slightly more – or 10 at a time – they have different colours etc.
My pal Jonathan introduced these to me a few days ago and I am SO glad he did! So basically this is what you get – a panel maybe 20mm x 16mm (finger size!) and they have a 3-way 0.1” connector on the back – power, ground, output. Power is 3v6 to 6v. Operation is simple – bring your finger near the panel – it lights up and the output is on – move your finger away, it goes off. If you want momentary action there’s a tiny pair of solder links for that, too. The proximity switching works through plastic – maybe 3mm or more?
Now that last point is really important as these really are not too much use on their own, not that pretty and with a band at the top – but they do light up evenly and brightly and that’s the point – with a case with some kind of legend, maybe a negative sheet with shapes – you know, my friend and I were responsible for the world’s first video jukeboxes (no, really, we were) and one of our first designs was a Perspex front with a large negative behind it – black with clear track titles etc… at the front we had large amusement machine-type buttons.. If ONLY these things had been available at the time !!!!
Sorry the picture is so crap, this is pre-digital camera, pre-Internet. But you can see the backlit negative. The mechanical buttons could have been completely replaced with touch areas.
Today, I’m thinking – negative with down (left triangle), menu (menu) and up (right triangle) – three of these on an ESP and some kind of display (the cheap SD1306 OLEDs at under £3) and you have a marvellous menu control for whatever – lighting, heating, house control – you name it. Just a little visual imagination… or maybe if you’re lucky enough to have a tiny engraver – engraved in a plastic front panel deep enough to let the light through – the list goes on. See what can be done with star-trek style control panels.. This example of a backlit panel got me fired up…
Want to take my Jukebox to futuristic extremes – check this out – stunning – and you could do this with these touch panels, a bit of plastic and a negative.. for VERY little outlay…
Oh, you want to see these in operation – I made a video and near the end of this short video where I talk about other stuff in the postbag… and here is the cheapest price I could find – including postage (well, the postage is free) 0.767 pence each… so many possibilities…
HOWEVER – as we look through the adverts it turns out there is a similar non-backlit version which is a lot cheaper. Do your own backlight? Edge lighting? Check this AliExpress link out.. Worth a play?
Yes, I have a pack of 20 of them and they work a treat. Stuck behind a plastic panel you can use them as simple switches or toggles. Normally the output is low until you touch (or get very near to) the switch – but this can be inverted by shorting junction A (and this is necessary if you want to use them with GPIO2 on an ESP8266 – well, mine anyway as they don’t like having GPIO2 low on power-up). As these work out at only a few pence each and avoid the need for input debouncing software, they are WELL worth considering.
So for example – the wall display – here is my QD-tech-based wall wifi information panel. See that space near the button under the display – well, I’ve fitted one of these touch switches (glue) on the inside – as above with the A link shorted (essential) – to GPIO2. See that TIME section up at the top – well, now when you touch the display, the SET heating temperature takes over that area for a while – repeatedly touching the box rotates the temperature up to 27c then back down to 14c and back up again… hence forming a dust-proof control for heating with no extra holes and only a few pence cost. Works a treat – check out the video – https://youtu.be/ac44RjPDHa8