Hello,
I am considering options for LED power supply or the selection of LED in general.
Let me outline the objective/some prior knowledge:
- I want to light a custom 3D print. I would like something more robust than a puck light with remote. It turns out the Bambulab Lab puck remote is defective that I have is a strange issue (the remote wont shut it off) which means I would have to dismantle the project to turn off the light. I have rockers for reliable power control.
- I would prefer it were using alkaline batteries in a compact space, up to 3AA's. That's 4.5v roughly. I am using RP2040 XIAO, they take in 5v but only send 3v3 signal. I figure I would need to wire the supply to a boost converter at minimum for a 5v LED and directly to the 5050RGB at 5 VIN, so not directly through the XIAO. Use the RP2040 only on the 3v3 digital input because the I/O at 5v will destroy it. The XIAO takes 5VIN, out 3v3 to D0 on the LED, the 5VIN to the 5050RGB LED. The 5050 LED has the Arduino driver board.
- For boost converter, I don't know what sort of risks I need to calculate here, the resistor is a concern as I am seeing mixed answers regarding LED resistors. Some use just Ohm's law which 5v in and 5v drop makes it nearly no resistance, but I am seeing 100-200 ohm resistors recommended for microcontroller controlled LED's. Why is that if the calculation is getting me about about 0v? V = I*R, or in this case the change in voltage and power. R = [(DeltaV)/I]*1000, the resistance and watts calculate to zero in the deltaV, so these requirements don't make sense to me.
- I have never used a boost converter before, I am studying up on it. So if you could help in regards to using the component would be grateful. It concerns me that if you use one the increased voltage might burn up something, or if you forget to turn it down. I am thinking of gluing with DP100 the knob to fix it at 5v using a multimeter.
- Battery life is a major hurdle, I aim at using just 3 batteries, so I need to figure out how to calculate the battery life using 20 mA RGB LED after boost converter. Artificial intelligence brought up that it may reduce battery life quite a bit, maybe to last no more than 20 hours? or 100 hours? It was giving confusing results. Typical puck light lasts 40 hours with one RGB LED inside it. It makes the DYI circuit kind of pointless if there's no better solution.
- Do 5v LEDs get real hot too if they have a MCU support board?
- I do not believe 3V RGB single LED's exist, or do they?
So I aim to learn more about boost converter safety, resistors, and LED options here.
I am considering just using a 3v white LED of some sort which would not need the PWM, otherwise just use PWM as a timer or dimmer control. Not sure where to find a good bright 3v LED for night light. However, the RGB is more impressive and of course with batteries a challenge.
RP2040 datasheets are at the bottom of the page.
I figure I am missing pieces of the puzzles, so I apologize if I couldn't be more specific.