Difference between revisions of "LED Matrix Failure"
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* Left->Right Left->Right | * Left->Right Left->Right | ||
+ | The Dotstar LEDs are arranged in a chained sequence. the intention was to cut the strips and align them with on the fabric in a left to right sequence similar to tradition LCD panels. this sequence is typically something like this for an 5x5 pixel example: | ||
+ | <pre> | ||
+ | 01 02 03 04 05 | ||
+ | 06 07 08 09 10 | ||
+ | 11 12 13 14 15 | ||
+ | 16 17 18 19 20 | ||
+ | 21 22 23 24 25 | ||
+ | </pre> | ||
+ | |||
+ | the issue with this that to implement this with the LED strips, two wires need to connect the end of one LED strip to the beginning of the next, in the 5x5 pixel example above, the SPI clock and data need to connect from the end at 05 to the beginning of the next line at 06. this creates a wiring nightmare on the back side of the design: | ||
+ | [[File:Backside-wiring-led.jpg|300px]] | ||
+ | [[File:Backside-closeup-led.jpg|300px]] | ||
+ | |||
* Left->Right Right->Left | * Left->Right Right->Left | ||
− | |||
= Connections = | = Connections = |
Revision as of 13:07, 2 September 2015
Goal
Document the failure and redesign of a LED Matrix display consisting of 30 strips of Adafruit Dotstar LEDs.
Components
- 57" x 30" Black Upholstery Fabric
- Metal Grommet Press
- Adafruit DotStar Digital LED Strip - Black 60 LED - Per Meter - BLACK
- Power Supply 5V@60A 350W
- Connectors
Layout
- Left->Right Left->Right
The Dotstar LEDs are arranged in a chained sequence. the intention was to cut the strips and align them with on the fabric in a left to right sequence similar to tradition LCD panels. this sequence is typically something like this for an 5x5 pixel example:
01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25
the issue with this that to implement this with the LED strips, two wires need to connect the end of one LED strip to the beginning of the next, in the 5x5 pixel example above, the SPI clock and data need to connect from the end at 05 to the beginning of the next line at 06. this creates a wiring nightmare on the back side of the design:
- Left->Right Right->Left
Connections
- power connections
- long wires
- broken flex pads
Signal Issues
- long SPI signals
- quick fix
PCB Design
- signals
- layout
- features
- eagle files
- soldering