So… the other day, a parcel turned up for me – some samples from Itead. One of the boxes contained 4 strips of LEDS and a controller. The strips are maybe 20mm wide aluminium with staggered SMT LEDs on them – first a warm LED, then a COLD LED then.. etc. Each strip is 500mm long and very thin.
The controller takes in 120-240v and gives out – wait for it…96-140v.
I must’ve stared at them for 20 minutes wondering why an EARTH anyone would want to have a set of lights working at such high DC voltages (I still remember as a VERY small child having one of the first battery power valve radios which had a pair of 90v batteries. I also remember being stretched out on the floor in front of the fire, having a great time playing with this new toy until I stuck my fingers across the battery connector, putting 180v DC straight across my chest – not nice).
Then there was the fact that the wires to the mains needed to be soldered to the board rather than screw fittings – and I put the thing to one side until one of our readers wrote in to say that he had figured out that the ESP8266-based controller had one LED on GPIO12 and the other on GPIO14. Well, I really could not be bothered to figure out how the default software on this WIFI-controlled lighting controller works) – so I made a change to my house control ESP software to allow GPIO14 to be an output (it’s on the source code and the OTA update elsewhere in the blog). I could do PWM but that is for another day, for now I simply added on-off control – and when testing I realised there’s a green indicator light in the unit which operates like a SONOFF – ie +v is OFF – my “sonoff:1” command makes that flash the right way.
So all well and good but I was still wondering what is wrong with ordinary LED STRIP. As this is serial you need a terminating connection at the far end taking the two ends from the lights to ground. I just used a blob of solder as somehow mine was missing out of the pack.
Over on the right you see the little stand-up processor board with the reset button and 4 way programming connector (3v3, serial and ground) – don’t try this at home with the mains plugged in!!
It was not until I turned the unit on complete with LED strips that I realised the point of the high voltage! BOY is that bright – and in the example you see above, only the COLD lights are on as I screwed up somewhere and the WARM lights are not on – I’ll fix that in daylight tomorrow. With both on, you could perform surgery there is so much light. In short – if you need overall lighting for a shed or small office – this absolutely does the job. They have screw holes all along the strip length – but I simply stuck double sided adhesive on the 4 lengths of strip and they’re holding onto the ceiling along with the controller, just fine.
If I could just convince Itead to use 32Mb (4MB) FLASH parts on all their products…