TM1637 Class Reference

API for the TM1637 7-Segment Display. More...

Detailed Description

• ID: tm1637
• Name: TM1637 7-Segment Display
• Other Names: Grove 4-Digit Display
• Category: display
• Manufacturer: seeed
• Connection: gpio

TM1637 is a display controller for LED-based 7-segment displays. It can be used to address and write data to multiple display digits. This driver is based on the Grove version of the TM1637 display that uses 4 digits, thus making it ideal for clock displays, timers, counters, or even score displays in a two-player arcade game.

    bool point = true;
    int timezone = -7; // Your UTC offset
    time_t rawtime;
    struct tm * gmt;
    char myTime[5];

    fprintf(stdout, "TM1637 Display Example\n");
    signal(SIGINT, sig_handler);

    TM1637 myDisplay = TM1637(0, 1); // TM1637 on pins 0 (clk) and 1 (dio)
    myDisplay.write(0x39, 0x09, 0x09); // Start a box using 7-segment encoding
    myDisplay.writeAt(3, ']'); // Finish box using writeAt function
    sleep(3); // Wait 3 seconds

    while(run)
    {
        time(&rawtime); // Update raw time
        gmt = gmtime(&rawtime); // Get current time

        int hour = (gmt) ? gmt->tm_hour : 0;
        int min = (gmt) ? gmt->tm_min : 0;
        // Format and store the time in 24 hour format
        snprintf(myTime, 5, "%2d%02d", (hour + timezone + 24) % 24, min);

        myDisplay.write(myTime); // Write to display as string
        myDisplay.setColon(point ^= true); // Toggle the dots on the display
        sleep(1); // Only update once every second
    }

Public Types
enum	M_FAST_GPIO { NO = 0, YES = 1 }

Public Member Functions
	TM1637 (int clk_pin, int dio_pin, int bright=3, M_FAST_GPIO mmio=YES)
	~TM1637 ()
mraa_result_t	write (uint8_t *digits)
mraa_result_t	write (int d,...)
mraa_result_t	writeAt (int index, char symbol)
mraa_result_t	write (std::string digits)
void	setColon (bool value)
void	setBrightness (int value)

Member Enumeration Documentation

enum M_FAST_GPIO

Enum for the memory-mapped GPIO

Constructor & Destructor Documentation

TM1637	(	int	clk_pin,
		int	dio_pin,
		int	bright = 3,
		M_FAST_GPIO	mmio = YES
	)

TM1637 constructor

Parameters

clk_pin	Clock pin the sensor is connected to
dio_pin	Data pin the sensor is connected to
bright	Initial brightness, from 0 (dark) to 7 (bright) (default is 3)
mmio	Fast memory-mapped GPIO writes; default is yes

~TM1637

(

)

TM1637 destructor

Member Function Documentation

mraa_result_t write

(

uint8_t *

digits

)

Writes digits to the display in a 7-segment encoding

Parameters

digits

Array of digits to send to the display

Returns

0 if successful, error code otherwise

mraa_result_t write	(	int	d,
			...
	)

Writes digits to the display in a 7-segment encoding

Parameters

d	List of multiple arguments to send to the display

Returns

0 if successful, error code otherwise

mraa_result_t writeAt	(	int	index,
		char	symbol
	)

Writes a symbol (digit or letter) to the display in a specified index

Parameters

index	0-based index of the digit to change from the left
symbol	Digit or letter to display

Returns

0 if successful, error code otherwise

mraa_result_t write

(

std::string

digits

)

Writes all the digits or letters to the display as a string

Parameters

digits

String of symbols to display

Returns

0 if successful, error code otherwise

void setColon

(

bool

value

)

Toggles the colon between digits on the display

Parameters

value

True to turn the colon on, false to turn it off

void setBrightness

(

int

value

)

Controls the brightness of the display

Parameters

value

Brightness, from 0 (darkest) to 7 (brightest)

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The documentation for this class was generated from the following files:

• /iotdk/jenkins/workspace/upm-doc-stable/src/tm1637/tm1637.h
• /iotdk/jenkins/workspace/upm-doc-stable/src/tm1637/tm1637.cxx