MIKROE-2153

Page 1 of 2 LED ring R click From MikroElektonika Documentation LED ring R click carries a ring of 32 red LEDs driven by four 8-bit 74HC595 serial-in, parallel-out shift registers. The ring is 25 mm in diameter. The click communicates with the target MCU through the mikroBUS™ SPI interface, with RST, CS, SCK, MISO and MOSI pins marked MR#, LAT, CLK, DSOUT, DSIN, respectively. Other LED colors will also be available. The board is designed to use either a 3.3V or 5V power supply only. LED ring R click Features and usage notes LED ring click is one of several click boards that employ 74HCP595 shift registers to drive LEDs. Rotary click use the same, as well as Bargraph click, 7-Seg click and 7x10 click. Using 8-bit shift registers to drive an array of LEDs is simply good practice, because it leaves more available pins on the target MCU, allowing you to either use a cheaper, lower pin count main MCU, or use the leftover pins for other purposes. Schematic also available in PDF (http://cdndocs.mikroe.com/images/9/94/LED_ring_R_click_sch The end result is a smaller, more cost effective design. Programming The following code snippet demonstrates different ways to communicate with the click and initializes a clockwork pattern with a single LED at a time. LED Ring R click IC/Module Led ring, 74HC595 serial in parallel out shift registers x4 Interface SPI Power 3.3V, 5V supply Website www.mikroe.com/click/led-ring-r (http://www.mikroe.com/click/led-ring-r) 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 sbit sbit #include #include LRR_LAT at GPIOD_ODR.B13; LRR_RST at GPIOC_ODR.B2; "led_ring_hw.h" void main() { uint8_t test_bfr[4]; uint8_t i = 0; uint16_t var_time = 500; uint32_t led = 0x00000001; // set latch and reset pins as output GPIO_Digital_Output(&GPIOD_BASE, _GPIO_PINMASK_13); GPIO_Digital_Output(&GPIOC_BASE, _GPIO_PINMASK_2); // initalize SPI SPI3_Init_Advanced( _SPI_FPCLK_DIV16, _SPI_MASTER | _SPI_8_BIT | _SPI_CLK_IDLE_LOW | _SPI_FIRST_CLK_EDGE_TRANSITION | _SPI_MSB_FIRST | _SPI_SS_DISABLE | _SPI_SSM_ENABLE | _SPI_SSI_1, &_GPIO_MODULE_SPI3_PC10_11_12); led_ring_hal_init(); led_ring_start(); test_bfr[0] test_bfr[1] test_bfr[2] test_bfr[3] = = = = 0xAA; 0xAA; 0xAA; 0xAA; led_ring_hal_write(&test_bfr, 4); // demonstration of HAL write function led_ring_latch(); Delay_ms(1000); led_ring_send_32 ( 0xFAFAFAFA ); // demonstration of writing 4 bytes Delay_ms(2000); led_ring_send_8 led_ring_send_8 led_ring_send_8 led_ring_send_8 ( ( ( ( test_bfr[0] test_bfr[0] test_bfr[0] test_bfr[0] while (1) { led_ring_send_32 ( led ); vDelay_ms(var_time); led = led