Hardware recommendations

[phenze]

Since a few people(including me) have several problems with their LED stripes can anybody recommend any LED Stripe which is working without trouble ?

Perhaps we can update the hardware list in the documentation with some points you have to pay attention when buying the hardware ?

It is kind frustrating when building the clock with cheap/broken LED Stripes and then searching errors for weeks.

[FrankX0]

I am not sure if there are LED strips out there which cause the problems people are facing (but probably there are). As long as you make sure they are based on WS2818B LEDs you should be fine. But of course there will be differences in strip quality regarding the manufacturing and the quality of the rest of the material. For what it's worth, I'm successfully using these. In my opinion the rest of the components and the routing of the connections are as important, probably even more important:

1. Use a level-shifter! Without one you cannot reliably interface the (3.3V) Pi to the (5V) strip. The minimum high voltage of the WS2812B is 0.7VDD, which result in a nominal value of 3.5V. The output high level of the Pi will be about 3V. So theoretically you cannot guarantee this to work without the level-shifter.
2. The quality of the 5V power-supply The cheap Chinese ones tend to generate a lot of noise, which especially in combination with not using a level-shifter will result in random flickering of the LEDs. I even had a supply which produced so much noise that it damaged the first LED in the strip, causing the entire strip to fail. Advise: use the smallest power-rating possible. Bigger is certainly not better!
3. Routing of interconnections Each LED can draw op to 50mA. Switching on 100 LED's at the same time can cause 5V power drops and ground shifts. If the routing of the interconnections is not done properly, this can interfere with the communication to the LEDs. Which then could result in wrong colours or incorrect LEDs turning on. Also in combination with a noise power-supply (and not using a level-shifter) this can cause all sorts of incorrect LED behaviour. Also make sure that the wiring from the power supply to the LED strip has a proper cross-section to deal with the currents. Use same/similar wiring as used by the manufacturer of the strip.
4. Decoupling Although I did not need it in my case, decoupling close to the LED strip could improve the stability of the power running through the strip.

Hope this helps.

[phenze]

Hello @FrankX0 , thank you for your input! (and for the great new Web Interface by the way !!)

Regarding your points i have the following input:

1. I will try this. Thank you. Is it complicated to connect the level shifter ?
2. Im wondering about that point. When you use the power supply you mentioned you have not enough power to get full brightness. The Strip you have mentioned have a Power Consumption of 18W/m (i guess thats for 60led/m). So our strips will have 9W/m. This means we need about 7A to get the full power ( 9W / 30 led = 0,3 W/led --> 114*0,3 / 5 = 6,84A). Do you have full brightness with your power supply ?
3. Do you have any recommendations for "soldering noobs". Is there any easy way to connect the strips ?
4. Don't know what that means ? Sorry.

[kimthostrup]

HI @phenze For point number 3, I have considered using these : https://www.ebay.com/itm/232374294719

[phenze]

@kimthostrup that's great !

Thank you !

[MaxZimmermann99]

Setup which works for me right now:

LED: https://www.amazon.de/gp/product/B07439RXD3/ref=oh_aui_detailpage_o01_s00?ie=UTF8&psc=1 PI: Raspberry Pi Zero Power: https://www.amazon.de/gp/product/B00MWQF08C/ref=oh_aui_detailpage_o02_s00?ie=UTF8&psc=1

Pi powered with 5V from LED power supply (did not work with Pi on USB) No levelshifter No buttons

Working fine, power supply only getting warm with all LEDs turned on.

[ruedli]

Regarding the power supply: I have built 3 clocks where I for each use an old notebook power supply (23V) and I use 5V step-down convertors to step down to 5V. I use minimal 5: one for the Pi and 4 for 4 groups of LEDS. The ground is common for all step-down convertors. All 3 clocks work. Advantages:

• No voltage loss over the cable of the otherwise 5V power supply, when you loose voltage of the 23V, it is compensated by the subsequent step-down convertor.
• The step-downs are quite close to the LEDS, so less power loss with the 5V circuitry.
• No common 5V between Pi and LEDS
• So far no interference, the clocks are running for many years now, I am building the 4th one now.

Because I also use servos and motors in my clocks, they use different step-downs set to 6V.

The build deviates from the current description, but so far my experience is quite good. Anyone else gone this route?