This project is an arena-style scoreboard with wireless remote control. There are 4 digits for the clock (timing) and 2 digits each for the team scores (8-digits total). Each digit is a 5x7 array consisting of 35 WS2811 LEDs (the pixels). Each digit is controlled by a GPIO line from an Arduino Mega 2650 (or similar). A 5x7 font ASCII character set is included.

The scoreboard and remote each have 3 switches. You can operate the 3 switches locally on the scoreboard or the 3 switches on the remote. Two switches control the score(s) and one other controls the clock timer. Press and hold a switch to clear its function. Press multiple switches at once to run test patterns (or create new features).

Scoreboard: The scoreboard is powered by an Arduino Mega 2650 (5VDC). There are 8 GPIO lines used to drive the data line for each string of WS2811 LEDs with 35 LEDs per string. The 3 momentary switches are wired to GPIO pins. Each switch is debounced in software using a state machine. An nRF24L01 2.4GHz radio transceiver (receiver) is wired to the SPI bus along with a GPIO for the radio's chip select CS. A GPIO relay circuit activates a buzzer when the time expires.

Remote: The remote is powered by a Feather 32u4 (3.3VDC). It is wired similar to the scoreboard in that 3 switches are wired to GPIO lines and the nRF24L01 radio transceiver (transmitter) is wired to the SPI bus with a chip select CS pin. A 1200mAh battery is connected to the VBAT+ charging connector on the Feather 32u4. The battery is recharged when this board is connected to a USB power source.

Bill of Materials (Electronics)

• Arduino Mega 2650 (chosen because of its pin count and 5V I/O)
• Switches, Momentary
• nRF24L01
• Power Supply, 5V 20A
• Wire, 22AWG
• Protoboard

• Adafruit Feather 32u4 Basic Proto #2771 (chosen because of its form factor, 3.3V I/O, onboard battery charger)
• Switches, Momentary
• nRF24L01
• Battery, LiPo 1200mAh
• Protoboard

This code is procedural and operates using the conventional Arduino setup/loop procedure.

Setup: The scoreboard's setup() function assigns the hardware pinouts and initializes the nRF24L01 radio as a receiver.

Loop: The scoreboard's loop() function performs these actions:

• Polling switches (debounce, press/release/hold state machine, creates a command based on what button was pressed)
• Polling radio receiver (for messages)
• Message Loop (decode)
• Timebase
• Time expired handler
• Rendering
• Fonts (5x7)

Setup: The remote's setup() function assigns the hardware pinouts and initializes the nRF24L01 radio as a transmitter.

Loop: The remote's loop() function performs these actions: Polling switches (same operation/code as scoreboards switches above)

Encodes and sends a message via the radio transmitter based on what button was pressed. See Protocol, next.

A minimalist message protocol sends a 1-byte command to indicate what button was pressed. A message header containing the characters "$SB>" indicates the start, device, and direction of the message. Optionally, a message length and checksum are added. The receive buffer on the nRF24L01 is 32-bytes.

The FastLED library is used to drive the LEDs.

The nRF24L01 library is used to drive the radio transceivers.

The main project is in the folder: scoreboard

The wireless remote project is in the folder: scoreboard_controller