BIG 7-SEG R click

Description

BIG 7-SEG R click is what you need if you want to add a seven-segment LED display to your project. This click features an SC10-21SRWA seven-segment display. Communication between the MCU and the SC10-21SRWA display is established via serial-IN, parallel-OUT shift register 74HC595 IC.

The click runs on either 3.3V of 5V power supply and communicates with the target MCU over an SPI interface.

Display

The click displays letters, numbers and symbols in highly readable form. It can be used in any simple interface and combined with other click boards. The color of the displayed character is red, as the R in the name of the click states.

Light intensity

The light intensity on the display is controlled via the PWM pin on the board.

Applications

Adding a seven-segment LED display to your device with SPI interface.

Specifications

Pinout diagram

This table shows how the pinout on BIG 7-SEG R click corresponds to the pinout on the mikroBUS™ socket (the latter shown in the two middle columns).

Notes	Pin					Pin	Notes
	NC	1	AN	PWM	16	PWM	Display light intensity control
Master Reset for 74HC595	MR	2	RST	INT	15	NC
Latch for 74HC595	LAT	3	CS	TX	14	NC
Clock for 74HC595	CLK	4	SCK	RX	13	NC
Serial Data from 74HC595 to MCU	DSO	5	MISO	SCL	12	NC
Serial Data from MCU to 74HC595	DSI	6	MOSI	SDA	11	NC
Data line when interfaced with 3.3V MCU	3.3V	7	+3.3V	+5V	10	5V	Data line when interfaced with 5V MCU and also power supply pin for display and the whole click hardware
Ground	GND	8	GND	GND	9	GND	Ground

Jumpers and settings

Information about onboard jumpers:

Programming

This demo is using BIG 7-SEG R click board to display characters in an endless loop, with fixed time interval whilst changing its PWM duty.

• Operating Voltage Range: 2.0 to 6.0 V
• Operating Temperature: – 55 to 125 C

This example for STM32F107VC MCU ( EasyMx PRO v7 for ARM ), resets and initializes the BIG 7-SEG R click board takes characters from the static array and displays them while changing PWM duty cycle, all in an endless loop.

 1 extern char dig_array[MAX_CHARACTERS];
2 
3 // Variables
4 unsigned short counter;
5 unsigned int luminosity;
6 unsigned int pwm_period;
7 int8_t valid;
8 
9 char demo_array[20] =
10 { 'M', 'I', 'K', 'R', 'O',
11 'E', 'L', 'E', 'K', 'T', 'R', 'O', 'N', 'I', 'K', 'A',
12 '2', '0', '1', '6'
13 };
14 
15 void main() 
16 {
17 // MCU Init
18 GPIO_Digital_Output(&GPIOD_ODR, _GPIO_PINMASK_13); // Set PORTD.B13 as digital input
19 GPIO_Digital_Output(&GPIOC_ODR, _GPIO_PINMASK_2); // Set PORTC.B2 as digital output
20 
21 // SPI Init
22 SPI3_Init_Advanced( _SPI_FPCLK_DIV16, _SPI_MASTER | _SPI_8_BIT |
23 _SPI_CLK_IDLE_LOW | _SPI_FIRST_CLK_EDGE_TRANSITION |
24 _SPI_MSB_FIRST | _SPI_SS_DISABLE | _SPI_SSM_ENABLE |
25 _SPI_SSI_1, &_GPIO_MODULE_SPI3_PC10_11_12 );
26 
27 // PWM Init
28 pwm_period = PWM_TIM5_Init(5000); // PWM Init on 5kHz
29 PWM_TIM5_Set_Duty(100, _PWM_NON_INVERTED, _PWM_CHANNEL1);
30 PWM_TIM5_Start(_PWM_CHANNEL1, &_GPIO_MODULE_TIM5_CH1_PA0);
31 
32 // 74HC595 Init
33 HC595_LAT = 0;
34 HC595_RES = 0;
35 HC595_reset();
36 
37 // Init counter and segment luminosity
38 counter = 0;
39 luminosity = 0;
40 
41 // Endless loop
42 while (1)
43 {
44 valid = seg_7_display(demo_array[counter]);
45 PWM_TIM5_Set_Duty(100 + luminosity, _PWM_NON_INVERTED, _PWM_CHANNEL1);
46 delay_ms(750);
47 luminosity += 100;
48 counter++;
49 if (counter == 20)
50 counter = 0; 
51 if (luminosity == 4000) 
52 luminosity = 0; 
53 }
54 }