“A cheap, but quality product, which I used for colour-coded notifications on my Zero and 3B. I would have preferred diffused LED lenses, but I'm guessing that would sacrifice brightness. At low brightness levels, the red green and blue LED elements are clearly visible while working near to the Pi. Nevertheless, that's a minor quibble, as I'm delighted with the product.
A possible tip for David M. above, and perhaps others: I experienced the same colour balance issues if "set_brightness" was anything other than 1, so ensure that you have "blinkt.set_brightness(1)" somewhere.”
“Brilliant piece of kit. First time I've ever plugged anything into my RPi and I was a little nervous, but this fitted really well and felt secure. Was able to get up and running in no time thanks to the Pimoroni libraries.”
“Great little addition to the pi, used as a status display in my application can be dimmed to be very untrusive at night, or really eye-catching during the day. Could be used for a wide range of projects, the LEDs are all nicely balanced too with similar colour consistency.”
“Blinkt! is £5 retail in quantities of one so set your expectations accordingly, but you won't do better for the money and it's worth getting if you need something like this.
Colour balance is rather off and also non-linear (but so it goes with LEDs: lux/mA is highly wavelength-dependent). To my eye, green is subjectively at least twice the strength of red and blue, and red is a little stronger than blue. 0xffff00 and 0x00ffff respectively give a yellow and cyan somewhat indistinct from green, and the problem is worse at the lowest levels where the discrete colour LEDs don't combine as well.
As a first approximation, divide the green value by two and you'll get better saturation and linearity than you would otherwise (at the cost of losing one bit of luminosity resolution, not that output levels are remotely a problem!) At the lowest levels, the divisor might need to be closer to three or four but two will do.
I recommend that you improvise a diffuser to provide better colour mixing and avoid the worst of the nonlinearity, especially if you want to use it in a low-lit environment. Without, it's much much too bright and you won't be able to make use of the full dynamic range without blinding yourself. A piece of medium-weight card or translucent plastic would probably do. A diffuser means higher output power and therefore more heat dissipation, so take care to allow for that. Be sure to use a decent power supply.”
