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I have a RPi project where I want to build but alas I'm a programmer, not an electrical engineer. I can solder things, but I couldn't tell you what resistor I needed to put where.

Anyway, I looked around and there's lots of led strips, but I need 25-30 separated leds that are individually addressable for my project.

I looked a lot but found nothing, I figured if anybody would know, it would be you guys.

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You can buy a couple of MCP23017 port expanders and connect them to the Pi's I2C bus (GPIO 2/3, pins 3/5).

Each MCP23017 has 16 GPIO so that gives you 32 outputs to which you can connect LEDs. You can connect up to 8 MCP23017 to the I2C bus.

  • I'll give this a go. Still not sure how to wire it without burning something out but I found a tutorial that seems to do what I'm trying to do... raspberrypi-spy.co.uk/2013/07/… – stu Nov 28 '15 at 15:54
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In addition to @joan's answer see: Powering and controlling hundreds of LEDs with a Raspberry pi

Especially if an off-the-shelf solution is wanted, this might be worth a look: individually addressable LED strips, e.g. based on the LPD8806 (example) that seems to have a Pi library.

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NeoPixels worked well for me: NeoPixels on Raspberry Pi

Very programmer friendly. I got everything up and running with no soldering, and the python library is very easy to use.

Separated leds, like these?

  • hmmm... neat stuff, though you pay what you get for. ~$1.00 an led seems kinda steep, though I don't need many of them. I ordered all the other stuff (the mcp23017) so if I can't muster the brains to make that work, I'll try this. Thanks. – stu Nov 29 '15 at 20:11
  • you can find people selling WS2811/2812 LEDs on alibaba. for me the attraction was a ease of the API. – russau Nov 30 '15 at 1:17

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