This is unique and cost effective solution to add seven segment display to your microcontroller based product with one microcontroller pin only. This seven segment display unit take commands in form of RS232/UART/TTL signal at 9600 baudrate. You have to just send 10 Bytes to display on seven segment.
Packet information as following.
Byte No : 0 1 2 3 4 5 6 7 8 9
Byte Value : 0xAA I D7 D6 D5 D4 D3 D2 D1 0xBB
0xAA - Start of packet
I - Intensity control (0-9)
D7:D1 - Seven Segment Display Value of each digit
0xBB - End of packet
Input : 5V DC
Display Digit : 7
Baudrate : 9600