回顾下之前的章节:
本文我们将介绍下SPI的概念,以及如何使用三线SPI的时序驱动DS1302时钟芯片,同时我们也将给出用模拟IO方式驱动DS1302的方法。
关键字:STM32,GD32,SPI,DS1302,三线SPI,半双工SPI
串行外设接口(Serial Peripheral Interface,缩写为SPI)提供了基于SPI协议的数据发送和接收功能,可以工作于主机或从机模式。SPI接口支持具有硬件CRC计算和校验的全双工和单工模式。有些SPI口还支持SPI四线主机模式。
常规的SPI信号描述如下图:
常规SPI信号描述
DS1302是由美国DALLAS公司推出的具有涓细电流充电能力的低功耗实时时钟芯片。它可以对年、月、日、周、时、分、秒进行计时,并且具有闰年补偿等多种功能。(百度百科)
DS1302的管脚配置:
DS1302的时序:
DS1302时序
可以看到:除了CE高低电平不一样,这个时序跟半双工的SPI是一样的。
半双工SPI
DS1302的寄存器配置:
DS1302寄存器
DS1302的时钟频率:
DS1302时钟频率
半双工SPI的基本初始化:
发送流程:
接收流程:
从网上找的代码,其原理就是用IO口反转来模拟高低电平。
GD32代码:
#include "io.h"
#include "io_gd32.h"
#include "common.h"
//#define DS1302_USING_SPI
/* PF7-SCK PF8-CE PF9-DATA */
#define CURRENT_SPI SPI4
#define RTC_RCU RCU_GPIOF
#define RTC_GPIO GPIOF
#define RTC_SCK_PIN GPIO_PIN_7
#define RTC_CE_PIN GPIO_PIN_8
#define RTC_DATA_PIN GPIO_PIN_9
#ifdef DS1302_USING_SPI
#define READ_MODE spi_disable(CURRENT_SPI); \
spi_bidirectional_transfer_config(CURRENT_SPI, SPI_BIDIRECTIONAL_RECEIVE); \
spi_enable(CURRENT_SPI);
#define WRITE_MODE spi_disable(CURRENT_SPI); \
spi_bidirectional_transfer_config(CURRENT_SPI, SPI_BIDIRECTIONAL_TRANSMIT); \
spi_enable(CURRENT_SPI);
#define CE_HIGH gpio_bit_set(RTC_GPIO, RTC_CE_PIN);
#define CE_LOW gpio_bit_reset(RTC_GPIO, RTC_CE_PIN);
#else
#define READ_MODE gpio_init_input_mode(RTC_RCU, RTC_GPIO, RTC_DATA_PIN);
#define WRITE_MODE gpio_init_output_mode(RTC_RCU, RTC_GPIO, RTC_DATA_PIN, GPIO_OSPEED_50MHZ, 0);
#define CE_HIGH gpio_bit_set(RTC_GPIO, RTC_CE_PIN);
#define CE_LOW gpio_bit_reset(RTC_GPIO, RTC_CE_PIN);
#define CLK_HIGH gpio_bit_set(RTC_GPIO, RTC_SCK_PIN);
#define CLK_LOW gpio_bit_reset(RTC_GPIO, RTC_SCK_PIN);
#define DATA_HIGH gpio_bit_set(RTC_GPIO, RTC_DATA_PIN);
#define DATA_LOW gpio_bit_reset(RTC_GPIO, RTC_DATA_PIN);
#define DATA gpio_input_bit_get(RTC_GPIO, RTC_DATA_PIN)
#endif
#define WRITE_FLAG_ADDR 0xC0
#define READ_FLAG_ADDR 0xC1
#define RTC_INIT_FLAG 0xA5
#define YEAR_BASE 2021
/* 默认起始时间2021年1月1日,星期五 */
time_t init_time = {YEAR_BASE, 1, 1, 0, 0, 0, 5};
void spi1_init(){}
#ifdef DS1302_USING_SPI
void spi5_init(void)
{
spi_parameter_struct spi_init_struct;
spi_i2s_deinit(CURRENT_SPI);
rcu_periph_clock_enable(RCU_SPI4);
/* SPI_MOSI pf9 */
gpio_init_af_mode(RTC_RCU, RTC_GPIO, RTC_DATA_PIN, GPIO_OSPEED_50MHZ, GPIO_AF_5);
/* SPI_SCK pf7 */
gpio_init_af_mode(RTC_RCU, RTC_GPIO, RTC_SCK_PIN, GPIO_OSPEED_50MHZ, GPIO_AF_5);
/* RTC CE */
gpio_init_output_mode(RTC_RCU, RTC_GPIO, RTC_CE_PIN, GPIO_OSPEED_50MHZ, 0);
CE_LOW;
/* SPI parameter config */
spi_init_struct.trans_mode = SPI_TRANSMODE_BDTRANSMIT;
spi_init_struct.device_mode = SPI_MASTER;
spi_init_struct.frame_size = SPI_FRAMESIZE_8BIT;
spi_init_struct.clock_polarity_phase = SPI_CK_PL_LOW_PH_1EDGE;
spi_init_struct.nss = SPI_NSS_SOFT;
spi_init_struct.prescale = SPI_PSC_64;
spi_init_struct.endian = SPI_ENDIAN_LSB;
spi_init(CURRENT_SPI, &spi_init_struct);
/* enable */
spi_enable(CURRENT_SPI);
}
static void spi_rtc_send_byte(uint8_t byte)
{
/* loop while data register in not empty */
while(RESET == spi_i2s_flag_get(CURRENT_SPI, SPI_FLAG_TBE));
/* send byte through the SPI peripheral */
spi_i2s_data_transmit(CURRENT_SPI, byte);
while(spi_i2s_flag_get(CURRENT_SPI, SPI_FLAG_TRANS));
}
static void write_ds1302(uint8_t address, uint8_t data)
{
WRITE_MODE;
CE_HIGH;
spi_rtc_send_byte(address);
spi_rtc_send_byte(data);
CE_LOW;
}
static uint8_t read_ds1302(uint8_t address)
{
uint8_t data;
/* send addr */
WRITE_MODE;
CE_HIGH;
spi_rtc_send_byte(address);
/* recive data */
READ_MODE;
while(RESET == spi_i2s_flag_get(CURRENT_SPI, SPI_FLAG_RBNE));
CE_LOW;
WRITE_MODE;
data = spi_i2s_data_receive(CURRENT_SPI);
while(spi_i2s_flag_get(CURRENT_SPI, SPI_FLAG_TRANS));
return data;
}
#else
void spi5_init() {
gpio_init_output_mode(RTC_RCU, RTC_GPIO, RTC_SCK_PIN, GPIO_OSPEED_2MHZ, 0);
gpio_init_output_mode(RTC_RCU, RTC_GPIO, RTC_DATA_PIN, GPIO_OSPEED_2MHZ, 0);
gpio_init_output_mode(RTC_RCU, RTC_GPIO, RTC_CE_PIN, GPIO_OSPEED_50MHZ, 0);
}
static void rtc_delay(int count) {
while (count) {
count--;
}
}
static void spi_rtc_send_byte(uint8_t value)
{
uint8_t index;
WRITE_MODE;
for (index = 0; index < 8; index++)
{
CLK_LOW;
if (value&0x01)
{
DATA_HIGH;
}
else
{
DATA_LOW;
}
rtc_delay(1);
CLK_HIGH;
rtc_delay(1);
value >>= 1;
}
//CLK_LOW;
}
static void spi_rtc_recive_byte(u8 *value) {
uint8_t index;
READ_MODE;
for (index = 0; index < 8; index++)
{
*value >>= 1;
CLK_HIGH;
rtc_delay(1);
CLK_LOW;
rtc_delay(1);
if (DATA == 1) {
*value |= 0x80;
} else {
*value &= 0x7F;
}
}
}
static void write_ds1302(uint8_t address, uint8_t data)
{
CLK_LOW;
CE_HIGH;
spi_rtc_send_byte(address);
spi_rtc_send_byte(data);
CLK_LOW;
CE_LOW;
}
static uint8_t read_ds1302(uint8_t address)
{
uint8_t data = 0;
CLK_LOW;
CE_HIGH;
spi_rtc_send_byte(address);
spi_rtc_recive_byte(&data);
CE_LOW;
return data;
}
#endif
STM32代码:
#include "io.h"
#include "io_stm32.h"
#include "common.h"
//#define DS1302_USING_SPI
/* PA5-SCK PA6-CE PA7-DATA */
#define CURRENT_SPI SPI1
#define RTC_RCC RCC_APB2Periph_GPIOA
#define RTC_GPIO GPIOA
#define RTC_SCK_PIN GPIO_Pin_5
#define RTC_CE_PIN GPIO_Pin_6
#define RTC_DATA_PIN GPIO_Pin_7
#ifdef DS1302_USING_SPI
#define READ_MODE SPI_Cmd(CURRENT_SPI, DISABLE); \
SPI_BiDirectionalLineConfig(CURRENT_SPI, SPI_Direction_Rx); \
SPI_Cmd(CURRENT_SPI, ENABLE);
#define WRITE_MODE SPI_Cmd(CURRENT_SPI, DISABLE); \
SPI_BiDirectionalLineConfig(CURRENT_SPI, SPI_Direction_Tx); \
SPI_Cmd(CURRENT_SPI, ENABLE);
#define CE_HIGH GPIO_SetBits(RTC_GPIO, RTC_CE_PIN);
#define CE_LOW GPIO_ResetBits(RTC_GPIO, RTC_CE_PIN);
#else
#define READ_MODE gpio_init(RTC_RCC, RTC_GPIO, GPIO_Mode_IPU, GPIO_Speed_50MHz, RTC_DATA_PIN);
#define WRITE_MODE gpio_init(RTC_RCC, RTC_GPIO, GPIO_Mode_Out_PP, GPIO_Speed_50MHz, RTC_DATA_PIN);
#define CE_HIGH GPIO_SetBits(RTC_GPIO, RTC_CE_PIN);
#define CE_LOW GPIO_ResetBits(RTC_GPIO, RTC_CE_PIN);
#define CLK_HIGH GPIO_SetBits(RTC_GPIO, RTC_SCK_PIN);
#define CLK_LOW GPIO_ResetBits(RTC_GPIO, RTC_SCK_PIN);
#define DATA_HIGH GPIO_SetBits(RTC_GPIO, RTC_DATA_PIN);
#define DATA_LOW GPIO_ResetBits(RTC_GPIO, RTC_DATA_PIN);
#define DATA GPIO_ReadInputDataBit(RTC_GPIO, RTC_DATA_PIN)
#endif
#define WRITE_FLAG_ADDR 0xC0
#define READ_FLAG_ADDR 0xC1
#define RTC_INIT_FLAG 0x35
#define YEAR_BASE 2021
/* 默认起始时间2021年1月1日,星期五 */
time_t init_time = {YEAR_BASE, 1, 1, 1, 0, 0, 5};
void spi5_init(void){}
#ifdef DS1302_USING_SPI
void spi1_init(void)
{
SPI_InitTypeDef SPI_InitStructure;
SPI_I2S_DeInit(CURRENT_SPI);
RCC_APB2PeriphClockCmd(RCC_APB2Periph_SPI1, ENABLE);
/* SPI_MOSI PA7 */
gpio_init(RTC_RCC, RTC_GPIO, GPIO_Mode_AF_PP, GPIO_Speed_50MHz, RTC_DATA_PIN);
/* SPI_SCK PA5 */
gpio_init(RTC_RCC, RTC_GPIO, GPIO_Mode_AF_PP, GPIO_Speed_50MHz, RTC_SCK_PIN);
/* RTC CE */
gpio_init(RTC_RCC, RTC_GPIO, GPIO_Mode_Out_PP, GPIO_Speed_50MHz, RTC_CE_PIN);
CE_LOW;
/* SPI parameter config */
SPI_InitStructure.SPI_Direction = SPI_Direction_1Line_Tx;
SPI_InitStructure.SPI_Mode = SPI_Mode_Master;
SPI_InitStructure.SPI_DataSize = SPI_DataSize_8b;
SPI_InitStructure.SPI_CPOL = SPI_CPOL_Low;
SPI_InitStructure.SPI_CPHA = SPI_CPHA_1Edge;
SPI_InitStructure.SPI_NSS = SPI_NSS_Soft;
SPI_InitStructure.SPI_BaudRatePrescaler = SPI_BaudRatePrescaler_64;
SPI_InitStructure.SPI_FirstBit = SPI_FirstBit_LSB;
SPI_InitStructure.SPI_CRCPolynomial = 7;
SPI_Init(CURRENT_SPI, &SPI_InitStructure);
SPI_Cmd(CURRENT_SPI, ENABLE);
}
static void spi_rtc_send_byte(uint8_t byte)
{
/* loop while data register in not empty */
while(RESET == SPI_I2S_GetFlagStatus(CURRENT_SPI, SPI_I2S_FLAG_TXE));
/* send byte through the SPI peripheral */
SPI_I2S_SendData(CURRENT_SPI, byte);
while(SPI_I2S_GetFlagStatus(CURRENT_SPI, SPI_I2S_FLAG_BSY));
}
static void write_ds1302(uint8_t address, uint8_t data)
{
WRITE_MODE;
CE_HIGH;
spi_rtc_send_byte(address);
spi_rtc_send_byte(data);
CE_LOW;
}
static uint8_t read_ds1302(uint8_t address)
{
uint8_t data;
/* send addr */
WRITE_MODE;
CE_HIGH;
spi_rtc_send_byte(address);
/* recive data */
READ_MODE;
while(RESET == SPI_I2S_GetFlagStatus(CURRENT_SPI, SPI_I2S_FLAG_RXNE));
CE_LOW;
WRITE_MODE;
data = SPI_I2S_ReceiveData(CURRENT_SPI);
while(SPI_I2S_GetFlagStatus(CURRENT_SPI, SPI_I2S_FLAG_BSY));
return data;
}
#else
void spi1_init() {
gpio_init(RTC_RCC, RTC_GPIO, GPIO_Mode_Out_PP, GPIO_Speed_50MHz, RTC_DATA_PIN);
gpio_init(RTC_RCC, RTC_GPIO, GPIO_Mode_Out_PP, GPIO_Speed_50MHz, RTC_CE_PIN);
gpio_init(RTC_RCC, RTC_GPIO, GPIO_Mode_Out_PP, GPIO_Speed_50MHz, RTC_SCK_PIN);
GPIO_ResetBits(RTC_GPIO, RTC_DATA_PIN | RTC_SCK_PIN | RTC_CE_PIN);
}
static void rtc_delay(int count) {
while (count) {
count--;
}
}
static void spi_rtc_send_byte(uint8_t value)
{
uint8_t index;
WRITE_MODE;
for (index = 0; index < 8; index++)
{
CLK_LOW;
if (value&0x01)
{
DATA_HIGH;
}
else
{
DATA_LOW;
}
rtc_delay(1);
CLK_HIGH;
rtc_delay(1);
value >>= 1;
}
}
static void spi_rtc_receive_byte(u8 *value) {
uint8_t index;
READ_MODE;
for (index = 0; index < 8; index++)
{
*value >>= 1;
CLK_HIGH;
rtc_delay(1);
CLK_LOW;
rtc_delay(1);
if (DATA == 1) {
*value |= 0x80;
} else {
*value &= 0x7F;
}
}
}
static void write_ds1302(uint8_t address, uint8_t data)
{
CLK_LOW;
CE_HIGH;
spi_rtc_send_byte(address);
spi_rtc_send_byte(data);
CLK_LOW;
CE_LOW;
}
static uint8_t read_ds1302(uint8_t address)
{
uint8_t data = 0;
CLK_LOW;
CE_HIGH;
spi_rtc_send_byte(address);
spi_rtc_receive_byte(&data);
CE_LOW;
return data;
}
#endif
对外接口代码:
#define DS1302_UNLOCK write_ds1302(0x8e, 0x00);
#define DS1302_LOCK write_ds1302(0x8e, 0x80);
void rtc_time_init(void)
{
uint8_t hour;
uint8_t hour_24 = 0;
if (read_ds1302(READ_FLAG_ADDR) != RTC_INIT_FLAG)
{
write_ds1302(0x84, hour_24);
set_rtc(init_time);
return;
}
hour = read_ds1302(0x85);
if (hour > 0x80)
{
// 12小时制转为24小时制
hour_24 = (hour > 0xA0)?(hour&0x1F)|DEC2BCD(12):(hour&0x1F);
write_ds1302(0x84, hour_24);
}
}
void set_rtc(time_t t)
{
uint8_t year = t.year - YEAR_BASE;
if(year >= 100) year = 0;
DS1302_UNLOCK;
/* 写入已经设置时间标记 */
write_ds1302(WRITE_FLAG_ADDR, RTC_INIT_FLAG);
write_ds1302(0x80, DEC2BCD(t.second));
write_ds1302(0x82, DEC2BCD(t.minute));
write_ds1302(0x84, DEC2BCD(t.hour));
write_ds1302(0x86, DEC2BCD(t.day));
write_ds1302(0x88, DEC2BCD(t.month));
write_ds1302(0x8c, DEC2BCD(year));
write_ds1302(0x8a, DEC2BCD(t.week));
DS1302_LOCK;
}
time_t get_rtc(void)
{
time_t t;
uint16_t year = read_ds1302(0x8d);
uint8_t month = read_ds1302(0x89);
uint8_t day = read_ds1302(0x87);
uint8_t hour = read_ds1302(0x85);
uint8_t minute = read_ds1302(0x83);
uint8_t second = read_ds1302(0x81);
uint8_t week = read_ds1302(0x8b);
t.year = BCD2DEC(year) + YEAR_BASE;
t.month = BCD2DEC(month);
t.day = BCD2DEC(day);
t.hour = BCD2DEC(hour);
t.minute = BCD2DEC(minute);
t.second = BCD2DEC(second);
t.week = BCD2DEC(week);
return t;
}
DS1302时间打印
GD32三线SPI驱动DS1302
GD32三线SPI驱动DS1302 WEEK数据
GD32 IO口模拟驱动DS1302
GD32 IO口模拟驱动DS1302 WEEK数据
STM32三线SPI驱动DS1302
STM32三线SPI驱动DS1302 WEEK数据
STM32 IO口模拟驱动DS1302
STM32 IO口模拟驱动DS1302 WEEK数据
--EOF--