Blog - All Comments

RE: Color Classification on ESP32Cam

Lorenz — Mon, 23 Sep 2024 09:40:20 GMT

I am trying to partly replicate the project. Could you maybe post your entire Code or did you already do that? I especially am unsure what the values for the constants WIDTH and BLOCK_SIZE are in your funciton that converts the rgb565 buffer to the rgb888 array.

RE: Simple light flicker meter

peterw1956 — Sun, 25 Oct 2020 13:30:41 GMT

Thanks kk99. Finally got a sensor! Now I just need to figure out how to get the board out of the case.

RE: Simple light flicker meter

peterw1956 — Wed, 29 Jul 2020 06:41:04 GMT

II am in Australia and finding it difficult to source the TSL250R ic. Is there an alternative that would be suitable please?

RE: LEDGrid Display # 2 : The Laser Activated Display

davedarko — Thu, 04 Jun 2020 19:39:50 GMT

Nice project! Have you thought about using other LED colors for the outer ring? This has some spaceship docking guide vibes [View:/resized-image/__size/16x16/__key/commentfiles/f7d226abd59f475c9d224a79e3f0ec07-183f8c79-052e-4770-8fe0-d0d3e9f4b109/contentimage_5F00_1.png:16:16]

RE: Arduino MSGEQ7 Light Organ - high power LED banks for your backyard party

akshitagupta15june — Sun, 24 May 2020 09:45:01 GMT

Have a look at my entry and please like and share #badass Woman Project Entry - Akshita Gupta

RE: Arduino MSGEQ7 Light Organ - high power LED banks for your backyard party

robogary — Wed, 20 May 2020 02:05:17 GMT

Hi [mention:4fc1f8ec139d4a8c83f9a6eb56f43bbb:e9ed411860ed4f2ba0265705b8793d05] and [mention:d25512d61e65470296ce2f82f47741ab:e9ed411860ed4f2ba0265705b8793d05]

Finally had a break in the weather, installed the light organ under the railings of the deck in back of my house.

Here is a test run.

https://youtu.be/NHUzB_AjNY0

Next Step is adding more LEDs and loud music ! It only uses half the deck railings for now. Bigger is better.

RE: Arduino MSGEQ7 Light Organ - high power LED banks for your backyard party

hobbit25 — Tue, 19 May 2020 21:09:23 GMT

Awesome! What are the part numbers of the MOSFETs you used?

RE: Easily LED

alexdbird — Sun, 03 May 2020 07:28:35 GMT

The reason I think measurements are so variable is the same reason the longer leads don’t work. The output of the LED is very high impedance. You can solve this to some extent with a resistor, but as the LED also has a very low output that loses some sensitivity. For the best results you need to use an op-amp. Powering an op-amp is a PITA though, so try a single rail one like an MCP-601 that can run on the same supply as the Arduino. You can also change the Vref on some chips to make the analogue inputs more sensitive.
Sorry I’m not awake enough to actually explain the impedance thing!

RE: Easily LED

jw0752 — Sun, 19 Apr 2020 22:20:11 GMT

Hi Paj,

I enjoyed the trip you took us on through your experiments. While everything you learned could have been googled and read it was great to see you actually put the wisdom of the net to the test in your experiments. It is amazing how often new things are learned. One thing that I learned a while ago and that surprised me is that even with our precise manufacturing procedures most semi conductor, including LEDs, come out of the factory with slightly different specs. This is probably why you were reading different voltages on your LEDs of the same color. If one wants two identical components it is necessary to search through a bunch to find two that are within the tolerance of similarity to each other that the designer requires.

Thanks for your post.

John

RE: Ski Lamp

three-phase — Sat, 18 Apr 2020 20:16:24 GMT

This is a great project, you have put a lot of effort into the project and the blog. Well done.

Kind regards

RE: Easily LED

jc2048 — Fri, 17 Apr 2020 11:50:50 GMT

I was curious about your reverse measurements. It's not something that you normally ever look at if you design with LEDs, you just go by what the datasheet tells you (which is usually 5V).

I've tried it with a few LEDs, but unfortunately I don't know what they are as they are from old bags that have been lying around for years (once upon a time, LEDs were part of my day job and these are some from spares that were kept on a storeroom shelf and never used). This is with a test current of about 20mA, but it's all a bit approximate. This isn't a piece of professional test equipment; it's just a lash-up with an Arduino, so take the results with a little skepticism.

Here's a red, clear, high brighness, narrow viewing angle

[View:/resized-image/__size/480x234/__key/commentfiles/f7d226abd59f475c9d224a79e3f0ec07-25fdfc61-5907-48ae-b4f2-36c9ab662349/contentimage_5F00_206729.png:480:234]

Here's a green, fairly high brightness

[View:/resized-image/__size/480x234/__key/commentfiles/f7d226abd59f475c9d224a79e3f0ec07-25fdfc61-5907-48ae-b4f2-36c9ab662349/contentimage_5F00_206730.png:480:234]

Finally here's one I do know the part number of, it's a Kingbright L-7104ID red LED (GaAsP/GaP), which is impressive.

[View:/resized-image/__size/480x234/__key/commentfiles/f7d226abd59f475c9d224a79e3f0ec07-25fdfc61-5907-48ae-b4f2-36c9ab662349/contentimage_5F00_206731.png:480:234]

That last one is getting very 'iffy'. This is my test circuit without an LED

[View:/resized-image/__size/480x234/__key/commentfiles/f7d226abd59f475c9d224a79e3f0ec07-25fdfc61-5907-48ae-b4f2-36c9ab662349/contentimage_5F00_206732.png:480:234]

so it only reaches -180V anyway and at -170V it's running out of 'steam' [current really] and it's probably just increased leakage that's folding it over and not an actual, sustained avalache.

All the above were happy to repetitively avalanch twice a second, but I also tried an old Nichia high-brightness true-blue and that failed almost immediately after showing a breakdown at about -70V. When they first came out they had to be treated carefully as static-prone components, so I'm not surprised it died quickly.

The low datasheet figure might be down to what can be tolerated before it starts to compromise other things like the lifetime, rather than anything to do with where it breaks down and what damage might then ensue.

As [mention:87db22544d8844169f5ec3635dfac969:e9ed411860ed4f2ba0265705b8793d05] points out, there's a relationship between the forward current and the forward voltage that you need to understand. If your power supply works constant-current to a reasonable accuracy, you could try increasing the current from about 1mA in small steps and seeing what the forward voltage is for each step. If you plot it on a graph, current against voltage, you'll soon see why applying 5V directly across the diode is problematic.

RE: PiFace, Raspberry, LabVIEW and LEDs

genebren — Thu, 16 Apr 2020 17:00:13 GMT

Great project/tutorial. This is a great opportunity for people to learn a bit about Pi,i and LabVIEW.

Well done.

RE: PiFace, Raspberry, LabVIEW and LEDs

shabaz — Thu, 16 Apr 2020 14:11:15 GMT

Hi Jan,

Very useful mix of technologies : ) It's virtually a mini-tutorial on controlling equipment!

RE: Arduino MSGEQ7 Light Organ - high power LED banks for your backyard party

Fred27 — Thu, 16 Apr 2020 10:45:53 GMT

This is a nice project, but it would be great to see it done with some analog electronics. I know it's a cliché, but this is screaming out for a 555 (or maybe 4 x 556) to replace that Arduino.

RE: Easily LED

Fred27 — Thu, 16 Apr 2020 10:27:18 GMT

What's critical for an LED is controlling the current, not the voltage. Search for "LED current limiting resistor" and you'll find some useful information. This might be a good place to start.