I loaded the ring test onto my LuMini setup (daisy chained), and it looked great when connected to my computer. Once I switched over to 3.7V LiPo battery or 4.5V AA battery, it looked barely on, as you can see here. Any ideas for what’s happening here and how I could fix the issue? Thanks in advance!
They’re being run via an ESP32 Thing. I used the following Arduino IDE code:
#include <FastLED.h>
// How many leds in your strip?
#define NUM_LEDS 40 // Two 1-inch rings, 20 LEDs each
// The LuMini rings need two data pins connected
#define DATA_PIN 16
#define CLOCK_PIN 17
// Define the array of leds
CRGB ring[NUM_LEDS];
void setup() {
LEDS.addLeds<APA102, DATA_PIN, CLOCK_PIN, BGR>(ring, NUM_LEDS);
LEDS.setBrightness(255);
}
void fadeAll() {
for (int i = 0; i < NUM_LEDS; i++)
{
ring[i].nscale8(250);
}
}
void loop() {
static uint8_t hue = 0;
//Rotate around the circle
for (int i = 0; i < NUM_LEDS; i++) {
// Set the i’th led to the current hue
ring[i] = CHSV(hue++, 150, 255); //display the current hue, then increment it.
// Show the leds
FastLED.show();
fadeAll(); //Reduce the brightness of all LEDs so our LEDs fade off with every frame.
// Wait a little bit before we loop around and do it again
delay(5);
}
}
How big is the LiPo? These need a lot of current, 3 AA batteries or a small capacity LiPo are not going to be able to provide that.
1 Like
Like Yellowdog said - you can test with only one LuMini hooked up to confirm (it’ll be much brighter than powering several)
If you have a benchtop power supply you can power the setup that way and determine the current draw of your setup to be able to calculate how big of a LiPo you’ll need
Hi YellowDog, thank you for that answer. That makes sense-- the LiPo is this one. I was under the misapprehension that just providing the right voltage would be enough. Do you think one of these would be enough? (Would one with higher mAh be even better, and is there a “too high mAh” that I should be aware of?)
Re. TS-Russell’s reply, I don’t have a benchtop power supply to check how much current it draws; is there a way to estimate that based on number of LEDs/brightness?-- And then how can you estimate how much current a given battery setup can deliver, since as far as I can tell it’s not a listed spec on the product pages?
Hi Russell, I don’t have a benchtop power supply to check how much current it draws; is there a way to estimate that based on number of LEDs/brightness?-- And then how can you estimate how much current a given battery setup can deliver, since as far as I can tell it’s not a listed spec on the product pages? (Would a battery with higher mAh be better, and is there a “too high mAh” that I should be aware of?)
Your comment also reminded me that at one point, I did test just one Lumini ring on the battery and it lit up well, it that provides any helpful benchmark.
The hookup guide says you can estimate using 60mA * number of LEDs to guesstimate the current needed @ full brightness…which is 3.6A in your case
So, the 2Ah battery above would last like 33 minutes, probably less…and 3.6A is probably near the max for those wires long-term
I’d look into something much bigger if they need to be run for any extended amount of time…or a wired supply if possible
Thank you, I appreciate that info.
I’m going to try to program them to use half (or fewer) of the LEDs at any given time, intuitively I think that should require less current and give better battery life. I’ll update to say how that goes once I get a chance to try.
