Adding Accent Lighting To My Raspberry Pi B+ Case

[zunebuggy]

I hope I picked the right section. This seemed the closest fit for my question.

I got a Rasberry Pi B+ and I have an old external hard drive that died. The case for the drive is perfect for the Raspberry Pi.

The Pi has two LEDs when powered up. I do not want to solder on the Raspberry Pi at all for fear of ruining it, but I would like to use two phototransistors (one of each LED) and use them to power two decorative glow LEDs inside the case. The front of the case has a grill and I already turned on the LEDs inside and they look awesome. One of the glow LEDs is a multicolor LED that runs on 5 volts. The other though is an array 5 green LEDs all powered by a CR032 watch type battery (or CMOS batter). It is 1.5 volts.

The Raspberry Pi uses any 5 volt supply (same connector as my Galaxy S4 cell phone). I want to avoid having to have two power cords, but if I do have to then so be it.

Can anyone help me design (just need a schematic) a board that will incorporate the phototransistors, a 5 volt bus to run the multicolor array and the step-down circuit to run the 1.5 volt LEDs and how would you mount the phototransistors over the LEDs?

I was thinking shrink tubing and super-glue. Kinda permanent though. There may be a better way?

I am able to make my own board from a schematic. I've worked a lot with optoisolators on breadboards. I guess this is similar except the LEDs I am working with are external and not inside the optoisolators.

If I am going about this the hard way or all wrong, let me know. I will say that I do not have any equipment that would allow me to solder the micro-components on the Raspberry Pi. My hands are way to shaky and my eyesight isn't what it was. do have a large magnifying glass and looked at the Pi up close and thought no way and getting my soldering iron near that

Thank you very much in advance.

 

[Gryd3]

I hope I picked the right section. This seemed the closest fit for my question.

I got a Rasberry Pi B+ and I have an old external hard drive that died. The case for the drive is perfect for the Raspberry Pi.

The Pi has two LEDs when powered up. I do not want to solder on the Raspberry Pi at all for fear of ruining it, but I would like to use two phototransistors (one of each LED) and use them to power two decorative glow LEDs inside the case. The front of the case has a grill and I already turned on the LEDs inside and they look awesome. One of the glow LEDs is a multicolor LED that runs on 5 volts. The other though is an array 5 green LEDs all powered by a CR032 watch type battery (or CMOS batter). It is 1.5 volts.

The Raspberry Pi uses any 5 volt supply (same connector as my Galaxy S4 cell phone). I want to avoid having to have two power cords, but if I do have to then so be it.

Can anyone help me design (just need a schematic) a board that will incorporate the phototransistors, a 5 volt bus to run the multicolor array and the step-down circuit to run the 1.5 volt LEDs and how would you mount the phototransistors over the LEDs?

I was thinking shrink tubing and super-glue. Kinda permanent though. There may be a better way?

I am able to make my own board from a schematic. I've worked a lot with optoisolators on breadboards. I guess this is similar except the LEDs I am working with are external and not inside the optoisolators.

If I am going about this the hard way or all wrong, let me know. I will say that I do not have any equipment that would allow me to solder the micro-components on the Raspberry Pi. My hands are way to shaky and my eyesight isn't what it was. do have a large magnifying glass and looked at the Pi up close and thought no way and getting my soldering iron near that

Thank you very much in advance.

I think you should rethink you're aversion to soldering to the Pi.
Get a meter and measure one side of the LED with reference to the Pi's ground.
If the voltage here is too low, we need to find the resistor responsible for current limiting to the LED and measure the ends of those.
If you find a reasonable voltage, you can simply use a tiny wire (like a 32 guage or something...) tin the tip of the wire, and lightly touch it to the point with a solder iron. Takes less than a second to attach. It won't be as robust as a more solid connection, but will be more than capable of driving an LED with a transistor.
From here, use one of the Pi's GPIO pins as a voltage source, and another as a ground. You can now directly drive the LED from the Pi. Congrats!
If you need to remove your modification, simply touch a solder iron to the tiny wire you touched to the Pi to melt the solder and remove! (If the connection is small enough you can simply bend the wire back and forth a couple time and have it cleanly snap off)
This requires no additional power supply, and aside from the 1 wire lightly soldered to the Pi, the remaining connections are made to the GPIO pin header on the Pi.
Additionally, you can add more LEDs and control them with a script on you Pi. It could give you more info, like overall CPU load, webpage views, access attempts, etc.
(Please remember that the power supplied by the USB socket is limited! I think the B+ still uses poly fuses, so avoid using high power LEDs and try to keep your power usage low. Remember that the USB charger you are using should be at at least 1000mA, although it's the same as your phone, it will be unstable on the chaper 500mA chargers.)

 

[BobK]

Why not plug the LEDs into a GPIO connector on the Pi? Then you could also do some wicked awesome flashing patterns as well!

Bob

 

[Gryd3]

Why not plug the LEDs into a GPIO connector on the Pi? Then you could also do some wicked awesome flashing patterns as well!

Bob

Would be great for 'additional' LEDs, but the onboard LEDs light up for power and activity which the GPIO can't duplicate 100%. Up to the OP, he could easily make a GPIO attached LED blink every time a webpage is loaded, or a file is accessed.

 

[zunebuggy]

Thank you. I will give it a try and let you know how it goes. Sadly, I don't think I can use the multicolor LED. Looking at the spec it is actually 12volt although I have lit it up using a 5 volt charger. Strange. I guess it is way brighter and will even look better if I apply 12 volts. Maybe I will just buy a multicolor LED and search this forum for a circuit where I can put 3 buttons on my Raspberry Pi case and adjust the RGB values to anything I want. That is what I hoped to be able to do. If I felt like green one day, I'd choose green, or red, purple, etc... you get it. The LED I have has a remote but I could do three RGB buttons or potentiometers.

I am having a good time building this. It is going to connect to my TV via the HDMI connector and it is going to be a retro gaming (emulator) computer. I have a long range wireless key board, mouse and two wireless controllers. I also am going to connect a 1TB external drive.

Thanks again.