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--- 2019_leds [2019/02/04 23:39] – created tell
+++ 2019_leds [2022/03/01 20:55] (current) – tell
@@ Line 1: / Line 1: @@
 After our success [[2018 LEDs | last year]] with status and decoration LED strips on the robot, we're doing somthing similar but better this year.
-Parts for 2019:
+====== Parts for 2019 ======
-  * Addressable LED strip http://www.revrobotics.com/rev-11-1198/
+  * Addressable LED strip http://www.revrobotics.com/rev-11-1198/  based on WS2812B chip
   * Arduino Uno processor  https://store.arduino.cc/usa/arduino-uno-rev3
   * Arduino proto shield  https://store.arduino.cc/usa/arduino-proto-shield-rev3-assembled
   * LM2596-based DC buck regulator board https://www.amazon.com/eBoot-LM2596-Converter-3-0-40V-1-5-35V/dp/B01GJ0SC2C
+  * silicon rectifier diodes 1N4004, 1N4005, 1N4006, or 1N4007. https://cdn.sparkfun.com/assets/2/c/2/d/6/1N400x-D.PDF
   * wire and connectors
+====== The general idea ======
+Its easy to hack up the addressable LED strip to an arduino and get it to blink following any of the tutorials on the web.  (TODO link here)
+In order to provide useful feedback to the drivers and spectators, the RoboRio will have to tell the arduino to change color or blink patterns.  If only a few patterns are needed, we can select these by changing the state of one or more Digitial Output wires from the rio, connected to digital inputs on the arduino.  If many complex patttern choices are needed, we'll change to a TTL or USB serial port for communication.
+The LED strip can easily use more +5v power than the arduino can provide: its rated 3 amps per meter if all LEDs at full brightness.   So we'll use a DC regulator board
+to turn 12v from the PDP into plenty of +5v current.  This is a similar function to what the VRM does.
+We'll mount the regulator board and some headers onto the arduino proto shield, so that it can all be plugged
+onto the top of the  arduino Uno board.  After wiring it all up, we'll design and 3d print an enclosure to protect the whole thing.
+====== Schematic ======
+**NOTE CHANGE from earlier:   Do not connect regulator board +5v to arduino UNO +5v.  It could backfeed into the USB connector when used for power and programming.  Drawing has been updated**
+We power the arduino with robot battery voltage, and let its internal regulator and power switching handle it.  Two series diodes drop the voltage of a fully-charged battery (13v) to below the arduino's maximum of 12v.
+{{ :ledhookup-cropped.png?600 |}}
+====== Caution ======
+** Caution: the arduino Uno and its proto board has power terminals marked +5v.  Do not connect them to LED strip power or to the regulator board.**
+====== Code ======
+https://github.com/Team-4795/Arduino-LEDs-2019
+====== Finished Hardware ======
+Here's the fully wired hardware.
+The arduino uno is on the bottom, with the custom wiring all
+located on the protoshield board.
+We decided not to use DIO pins to signal from the RoboRIO to the arduino, instead we planned to use
+the USB port.
+{{ :img_20190226_192524588.jpg?400 |}}
+But this arduino project never actually made it onto the robot.  Not enough time was allowed for integrating the arduino code with the RoboRIO code.