I purchased two Neopixel rings (16 leds).
One of the rings works flawlessly, but the second has a weird behavior: when I address led n.0, led 14 lights too, if I address led n.1, led 15 lights too.
If I address led 14 or led 15 nothing happens.
Leds 0 and 14 seem coupled together and so leds 1 and 15.
16 leds Neopixel ring
Moderators: adafruit_support_bill, adafruit
Please be positive and constructive with your questions and comments.
- adafruit_support_mike
- Posts: 67454
- Joined: Thu Feb 11, 2010 2:51 pm
Re: 16 leds Neopixel ring
That's definitely unusual. Could you post a photo of the front and back of the ring please?
-
- Posts: 3
- Joined: Fri Mar 21, 2014 1:23 pm
Re: 16 leds Neopixel ring
here are pictures:
#include <Adafruit_NeoPixel.h>
#define PIN 2
Adafruit_NeoPixel pixels = Adafruit_NeoPixel(16, PIN);
//uint32_t color = 0xFF0000; // Start red
void setup() {
pixels.begin();
pixels.setBrightness(20);
// switch on led 0, color pale red
pixels.setPixelColor(0, 0xFF0000);
pixels.show();
}
void loop() {
}
This is the code I used to switch led 0 and 14 (or 1 and 15) on:#include <Adafruit_NeoPixel.h>
#define PIN 2
Adafruit_NeoPixel pixels = Adafruit_NeoPixel(16, PIN);
//uint32_t color = 0xFF0000; // Start red
void setup() {
pixels.begin();
pixels.setBrightness(20);
// switch on led 0, color pale red
pixels.setPixelColor(0, 0xFF0000);
pixels.show();
}
void loop() {
}
- adafruit_support_mike
- Posts: 67454
- Joined: Thu Feb 11, 2010 2:51 pm
Re: 16 leds Neopixel ring
Check for a solder bridge here:
Pixel 0 is actually two spaces clockwise of the IN pad, as shown. We had to backtrack the signals a little to make all the connections work.
The pin closest to the IN pad on pixel 1 is DATA-OUT, which connects to DATA-IN on pixel 2. If a bit of stray solder connected the IN pad to pixel 1's DATA-OUT, the ring would see signals entering at two places. The results would match what you're seeing.
Pixel 0 is actually two spaces clockwise of the IN pad, as shown. We had to backtrack the signals a little to make all the connections work.
The pin closest to the IN pad on pixel 1 is DATA-OUT, which connects to DATA-IN on pixel 2. If a bit of stray solder connected the IN pad to pixel 1's DATA-OUT, the ring would see signals entering at two places. The results would match what you're seeing.
-
- Posts: 3
- Joined: Fri Mar 21, 2014 1:23 pm
Re: 16 leds Neopixel ring
I checked leds contacts and I didn't notice any stray solder, tomorrow I'll try to remove all the solder paste with a desoldering braid.
However some weird behaviors remain.
I thought the pixel 0 was the one you call pixel 2 because:
a) when I switch on pixels 0 two pixels light (now I know be 0 and 2)
b) when I switch on pixels 14 and 15 nothing happens
c) when I switch on pixels 2, 3 to pixel 13, all of them light in the same order starting from the position now I know be 4
so I wrongly guessed that all pixels was shifted toward left by two positions.
A short summary (using correct pixels numbers):
if I switch on pixel 0, pixels 0 and 2 light;
if I switch on pixel 1, pixels 1 and 3 light;
if I switch on pixels 2 to 13, pixels 4 to 15 light
if I switch on pixel 14 or 15, nothing happens.
Is this behavior compatible with false contacts near IN pad?
Thank you for all extremely quick answers.
However some weird behaviors remain.
I thought the pixel 0 was the one you call pixel 2 because:
a) when I switch on pixels 0 two pixels light (now I know be 0 and 2)
b) when I switch on pixels 14 and 15 nothing happens
c) when I switch on pixels 2, 3 to pixel 13, all of them light in the same order starting from the position now I know be 4
so I wrongly guessed that all pixels was shifted toward left by two positions.
A short summary (using correct pixels numbers):
if I switch on pixel 0, pixels 0 and 2 light;
if I switch on pixel 1, pixels 1 and 3 light;
if I switch on pixels 2 to 13, pixels 4 to 15 light
if I switch on pixel 14 or 15, nothing happens.
Is this behavior compatible with false contacts near IN pad?
Thank you for all extremely quick answers.
- adafruit_support_mike
- Posts: 67454
- Joined: Thu Feb 11, 2010 2:51 pm
Re: 16 leds Neopixel ring
That's exactly what I'd expect from a connection between the input line and DIN for pixel #2.
Try getting well-lit macro photos of the front and back of the ring in the area around the DIN pin. If you don't have a solder bridge, there might be a stray connection in the PBC. Those are rare but not impossible, and the black soldermask would make it hard to see one without looking for it specifically.
Try getting well-lit macro photos of the front and back of the ring in the area around the DIN pin. If you don't have a solder bridge, there might be a stray connection in the PBC. Those are rare but not impossible, and the black soldermask would make it hard to see one without looking for it specifically.
Please be positive and constructive with your questions and comments.