Bluetooth Low-Power ble: Controls gpio to light LEDs

This section describes the simplest and most basic things. The ios operation of the cc2540 uses the Port port as the gpio. If you don't talk much about it, let's look at it.

1. Hardware Circuit

The most simple hardware circuit is to use a gpio to control the LED light. Since gpio is used as the output, the gpio mode is not required.

It is quite simple to control the gpio on the left to switch the LED lights.

2. Related registers

P0sel	P0 [] registers, which are set as common I/O ports by default
P0indium	P0 [] can be used as the circuit mode register when the input port is used as the input port.
P0	P0 [] I/O registers addressable
P0dir	P0 port input and output settings register

P0sel 0: Common IO port 1: second function

P0dir 0: Input 1: Output

P0indium 0: Pull up/pull down 1: three States

3. Code Implementation

Let's take p1_0 as an example to see how it is implemented in the code.

Halledinit function in hal_led.c:

void HalLedInit (void){#if (HAL_LED == TRUE)  HalLedSet(HAL_LED_ALL, HAL_LED_MODE_OFF);  // Initialize all LEDs to OFF.  // Set LED GPIOs to outputs.  LED1_DDR |= LED1_BV;#if (!defined HAL_PA_LNA && !defined HAL_PA_LNA_CC2590)  LED2_DDR |= LED2_BV;#if (!defined CC2540_MINIDK && !defined HAL_BOARD_CC2540USB)  LED3_DDR |= LED3_BV;#endif#endif#if defined BLINK_LEDS  HalLedStatusControl.sleepActive = FALSE;  // Initialize sleepActive to FALSE.#endif#endif

Macro definition

/* 1 - Green */#define LED1_BV                        BV(0)#define LED1_SBIT                      P1_0#define LED1_DDR                       P1DIR#define LED1_POLARITY                  ACTIVE_HIG

Switch led

  #define HAL_TURN_OFF_LED1()       st( LED1_SBIT = LED1_POLARITY (0); )  #define HAL_TURN_OFF_LED2()       st( LED2_SBIT = LED2_POLARITY (0); )  #define HAL_TURN_OFF_LED3()       st( LED3_SBIT = LED3_POLARITY (0); )  #define HAL_TURN_OFF_LED4()       HAL_TURN_OFF_LED1()  #define HAL_TURN_ON_LED1()        st( LED1_SBIT = LED1_POLARITY (1); )  #define HAL_TURN_ON_LED2()        st( LED2_SBIT = LED2_POLARITY (1); )  #define HAL_TURN_ON_LED3()        st( LED3_SBIT = LED3_POLARITY (1); )  #define HAL_TURN_ON_LED4()        HAL_TURN_ON_LED1(

Extract the key code:

1) set p1_0 to output

P1_DIR |= 0x01;

2) Set p1_0 to a high level to light the LED

P1_0 = 1;

2) Set p1_0 to low and turn off the LED

P1_0 = 0;

In fact, it is not difficult to look at the Hal encapsulation for each interface in the protocol stack.

This section is here first.

Bluetooth Low-Power ble: Controls gpio to light LEDs