Adafruit 0.56" 7-Segment Backpack and SAMD21 Xplained pro

if you want to display numbers using 7 segment , there are many choices to choose from , in this quick tutorial I will use Adafruit 0.56" 7-Segment Backpack based on HT16K33 (controlled through I2C ).

I re-write the code based on Adafruit library to work with Atmel studio and ASF4

you can use any ATMEL/Microchip Xplained pro / mini board to run this code "but you need to setup your configuration first on Atmel start

Connection

7segment samd21 xplained Pro

SCL >> PA09

SDA >> PA08

VCC >> VCC(3.3V)

GND >> GND

I write the code without a library so you can use it to build your own library

functions

begin(address)

start I2C communication , default address 0x70

void setBrightness(uint8_t b)

set the brightness for the 7 segment ,where

b : brightness level ( 0 - 15 )

writeDigitNum(digit ,number,dot)

write a number to a specific digit

where

digit : where to write the number

number : number to display

dot : if you want the dot to be on or off

void printNumber(long n, uint8_t base)

display an integer number , where

n: number

base: number format (BIN,DEC,HEX)

void printFloat(double n, uint8_t fracDigits, uint8_t base)

print a float number ,where

n: number

fracDigits: number of fractional number to display

base:number format (BIN,DEC,HEX)

void drawColon(bool state)

void writeColon(void)

draw a colon and active it using writeColon function

simple Code:

simple demo code to show you the basic functions

download the code from github

display Time using built-in RTC

this is another code to display time on the 7 segment

disadvantage: SAMD21 doesn't have a backup battery (no VDD line for RTC voltage source) so you will lost the time whenever you power it off or reset the board .