philkes / ledspielanzeige

LEDSpielAnzeige - Controller for LED Scoreboard

Display

• 2 x 8 7-Segment Displays
• Eacg Segment 7 LEDs in Series (Vfor=1.9V)
• Center Segments 8 LEDs in Series
• All Anodes (+) of the same Segments connected (all SegA,...) (Data)
• LEDs of a single 7-Segment Display have a common Cathode (-) (Address)
• DecimalPoint connections for ":",">","|",...

Connections

• 2x 16Pin Cable connections
• 8 Pin Address (only a single Bit "1" at a time)
• 8 Pin Data (7-Segments)
• Addresses are multiplexed

Schematic

Board

Mirrored Image for Soldering

Parts

• LM2596 Step-Down DC Buck Converter
• IC Sockel 14/16pin
• Perboard 16x10cm
• WeMos D1 mini
• DCAdapter 24V

Drivers

• UDN 2981(=TD62783AP) Source Driver
• ULN2803 NPN Darlington Arrays
• 74HC595 Shift Register

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Code

Wemos Arduino Sketch

• Multiplexing both Addressbusses (Common Cathodes) (ULN2803s "B1-B8"+"C1-C8") with 1x 74HC595 ("U2") output
• Loading 7-Segment Data (Anodes) for every Display concurrent to multiplexing with 2x 74HC595 ("U1"+"U3")
• Switch modes on WiFi commands

React Web App

• WebServer for User Interface
• Sending Commands over WiFi
• ESP8266-React Framework

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Links

• ULN2803 Function
• Arduino Forum Thread