Micropython Seven segment display

This library implements a class for easier usage of seven segment displays with multiple digits.

It is only tested on the Raspberry Pi Pico (H) with micropython 1.19.1, but it should work on all newer versions of micropython and other boards, that support micropython and are fast enough, that the display doesn't flicker.

Usage

For the simplest example refer to the pinout of your display (found in the datasheet, for example this one). The example table uses the following pin names:

Connect the pins as folowing:

Raspberry Pi Pico	Display Pin
GPIO 16	1 (first digit)
GPIO 17	2 (second digit)
GPIO 18	3 (third digit)
GPIO 19	4 (fourth digit)
GPIO 15	a (top)
GPIO 14	b (top right)
GPIO 13	c (bottom right)
GPIO 12	d (bottom)
GPIO 11	e (bottom left)
GPIO 10	f (bottom right)
GPIO 9	g (top left
GPIO 8	p (point)

Use the following code:

digits = [16, 17, 18, 19]
segments = [15, 14, 13, 12, 11, 10, 9, 8]
display = sevSeg(digits, segments, sevSeg.COMMON_CATHODE)

display.setString("3.141")

while True:
    display.refreshDisplay()

Functions

Constructor sevSeg(digits, segments, common, led_on_time, digit_delay)

• digits (type list) specify the digit pins (numbers of GPIO Pins)
• segments (type list) specify the segment pins (numbers of GPIO Pins)
• common (either COMMON_CATHODE or COMMON_ANODE), default: COMMON_CATHODE
  • which one to choose is listed in the datasheet of your display
• led_on_time (type int): how long the led should be turned on per cycle [microseconds], default 5000us
• digit_delay (type int): how long all leds should be off between the digits [microseconds], default 0us

The combination of led_on_time and digit_delay define the refresh rate and brightness of your display. If your display is flickering, try adjusting these values.

sevSeg.setDigit(digit, character)

• digit (type int): which digit to set (0 = first digit)
• character (type string): which character to display (complete list below)

Sets the character to be displayed on the specified digit.

sevSeg.setComma(digit)

• digit (type int): which digit to set (0 = first digit)

Sets the comma to be displayed after the specified digit.

sevSeg.setString(string)

• string (type string): which string to display

The string can only contain the characters listed in the complete list below. It can only display as many digits as specified in the constructor and at max one dot/comma after each digit.

If the string contains two dots/commas, there will be inserted a space between them. If the first character is a dot/comma, the first digit will be empty.

The function supports both '.' and ',' as dot/comma (also mixed).

sevSeg.refreshDisplay()

Refreshes the display. This function has to be called in a loop, otherwise the display won't show anything.

Supported characters

CHAR	ABCDEFGP	ASCII DEC	ASCII HEX	Note
'0'	11111100	48	0x30
'1'	01100000	49	0x31
'2'	11011010	50	0x32
'3'	11110010	51	0x33
'4'	01100110	52	0x34
'5'	10110110	53	0x35
'6'	10111110	54	0x36
'7'	11100000	55	0x37
'8'	11111110	56	0x38
'9'	11110110	57	0x39
'A'	11101110	65	0x41
'b'	00111110	66	0x42
'C'	10011100	67	0x43
'd'	01111010	68	0x44
'E'	10011110	69	0x45
'F'	10001110	70	0x46
'G'	10111100	71	0x47
'H'	01101110	72	0x48
'I'	00001100	73	0x49
'J'	01110000	74	0x4A
'K'	01101110	75	0x4B	Same as 'H'
'L'	00011100	76	0x4C
'M'	00000000	77	0x4D	NO DISPLAY
'n'	00101010	78	0x4E
'O'	11111100	79	0x4F
'P'	11001110	80	0x50
'q'	11100110	81	0x51
'r'	00001010	82	0x52
'S'	10110110	83	0x53
't'	00011110	84	0x54
'U'	01111100	85	0x55
'V'	01111100	86	0x56	Same as 'U'
'W'	00000000	87	0x57	NO DISPLAY
'X'	01101110	88	0x58	Same as 'H'
'y'	01110110	89	0x59
'Z'	11011010	90	0x5A	Same as '2'
' '	00000000	32	0x20	BLANK
'-'	00000010	45	0x2D	DASH
'.'	00000001	46	0x2E	DOT/COMMA
'*'	11000110	42	0x2A	STAR
'_'	00010000	95	0x5F	UNDERSCORE