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316 lines
9.2 KiB
316 lines
9.2 KiB
/******************************************************************************
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* Copyright 2013-2014 Espressif Systems (Wuxi)
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*
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* FileName: i2c_master.c
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*
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* Description: i2c master API
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*
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* Modification history:
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* 2014/3/12, v1.0 create this file.
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*******************************************************************************/
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#include "ets_sys.h"
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#include "osapi.h"
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#include "gpio.h"
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#include "driver/i2c_master.h"
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LOCAL uint8 m_nLastSDA;
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LOCAL uint8 m_nLastSCL;
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/******************************************************************************
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* FunctionName : i2c_master_setDC
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* Description : Internal used function -
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* set i2c SDA and SCL bit value for half clk cycle
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* Parameters : uint8 SDA
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* uint8 SCL
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* Returns : NONE
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*******************************************************************************/
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LOCAL void ICACHE_FLASH_ATTR
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i2c_master_setDC(uint8 SDA, uint8 SCL)
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{
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SDA &= 0x01;
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SCL &= 0x01;
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m_nLastSDA = SDA;
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m_nLastSCL = SCL;
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if ((0 == SDA) && (0 == SCL)) {
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I2C_MASTER_SDA_LOW_SCL_LOW();
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} else if ((0 == SDA) && (1 == SCL)) {
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I2C_MASTER_SDA_LOW_SCL_HIGH();
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} else if ((1 == SDA) && (0 == SCL)) {
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I2C_MASTER_SDA_HIGH_SCL_LOW();
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} else {
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I2C_MASTER_SDA_HIGH_SCL_HIGH();
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}
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}
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/******************************************************************************
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* FunctionName : i2c_master_getDC
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* Description : Internal used function -
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* get i2c SDA bit value
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* Parameters : NONE
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* Returns : uint8 - SDA bit value
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*******************************************************************************/
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LOCAL uint8 ICACHE_FLASH_ATTR
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i2c_master_getDC(void)
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{
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uint8 sda_out;
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sda_out = GPIO_INPUT_GET(GPIO_ID_PIN(I2C_MASTER_SDA_GPIO));
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return sda_out;
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}
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/******************************************************************************
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* FunctionName : i2c_master_init
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* Description : initilize I2C bus to enable i2c operations
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* Parameters : NONE
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* Returns : NONE
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*******************************************************************************/
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void ICACHE_FLASH_ATTR
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i2c_master_init(void)
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{
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uint8 i;
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i2c_master_setDC(1, 0);
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i2c_master_wait(5);
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// when SCL = 0, toggle SDA to clear up
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i2c_master_setDC(0, 0) ;
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i2c_master_wait(5);
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i2c_master_setDC(1, 0) ;
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i2c_master_wait(5);
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// set data_cnt to max value
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for (i = 0; i < 28; i++) {
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i2c_master_setDC(1, 0);
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i2c_master_wait(5); // sda 1, scl 0
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i2c_master_setDC(1, 1);
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i2c_master_wait(5); // sda 1, scl 1
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}
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// reset all
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i2c_master_stop();
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return;
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}
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/******************************************************************************
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* FunctionName : i2c_master_gpio_init
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* Description : config SDA and SCL gpio to open-drain output mode,
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* mux and gpio num defined in i2c_master.h
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* Parameters : NONE
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* Returns : NONE
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*******************************************************************************/
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void ICACHE_FLASH_ATTR
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i2c_master_gpio_init(void)
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{
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ETS_GPIO_INTR_DISABLE() ;
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// ETS_INTR_LOCK();
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PIN_FUNC_SELECT(I2C_MASTER_SDA_MUX, I2C_MASTER_SDA_FUNC);
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PIN_FUNC_SELECT(I2C_MASTER_SCL_MUX, I2C_MASTER_SCL_FUNC);
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GPIO_REG_WRITE(GPIO_PIN_ADDR(GPIO_ID_PIN(I2C_MASTER_SDA_GPIO)), GPIO_REG_READ(GPIO_PIN_ADDR(GPIO_ID_PIN(I2C_MASTER_SDA_GPIO))) | GPIO_PIN_PAD_DRIVER_SET(GPIO_PAD_DRIVER_ENABLE)); //open drain;
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GPIO_REG_WRITE(GPIO_ENABLE_ADDRESS, GPIO_REG_READ(GPIO_ENABLE_ADDRESS) | (1 << I2C_MASTER_SDA_GPIO));
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GPIO_REG_WRITE(GPIO_PIN_ADDR(GPIO_ID_PIN(I2C_MASTER_SCL_GPIO)), GPIO_REG_READ(GPIO_PIN_ADDR(GPIO_ID_PIN(I2C_MASTER_SCL_GPIO))) | GPIO_PIN_PAD_DRIVER_SET(GPIO_PAD_DRIVER_ENABLE)); //open drain;
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GPIO_REG_WRITE(GPIO_ENABLE_ADDRESS, GPIO_REG_READ(GPIO_ENABLE_ADDRESS) | (1 << I2C_MASTER_SCL_GPIO));
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I2C_MASTER_SDA_HIGH_SCL_HIGH();
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ETS_GPIO_INTR_ENABLE() ;
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// ETS_INTR_UNLOCK();
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i2c_master_init();
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}
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/******************************************************************************
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* FunctionName : i2c_master_start
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* Description : set i2c to send state
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* Parameters : NONE
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* Returns : NONE
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*******************************************************************************/
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void ICACHE_FLASH_ATTR
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i2c_master_start(void)
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{
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i2c_master_setDC(1, m_nLastSCL);
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i2c_master_wait(5);
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i2c_master_setDC(1, 1);
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i2c_master_wait(5); // sda 1, scl 1
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i2c_master_setDC(0, 1);
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i2c_master_wait(5); // sda 0, scl 1
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}
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/******************************************************************************
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* FunctionName : i2c_master_stop
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* Description : set i2c to stop sending state
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* Parameters : NONE
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* Returns : NONE
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*******************************************************************************/
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void ICACHE_FLASH_ATTR
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i2c_master_stop(void)
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{
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i2c_master_wait(5);
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i2c_master_setDC(0, m_nLastSCL);
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i2c_master_wait(5); // sda 0
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i2c_master_setDC(0, 1);
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i2c_master_wait(5); // sda 0, scl 1
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i2c_master_setDC(1, 1);
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i2c_master_wait(5); // sda 1, scl 1
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}
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/******************************************************************************
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* FunctionName : i2c_master_setAck
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* Description : set ack to i2c bus as level value
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* Parameters : uint8 level - 0 or 1
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* Returns : NONE
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*******************************************************************************/
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void ICACHE_FLASH_ATTR
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i2c_master_setAck(uint8 level)
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{
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i2c_master_setDC(m_nLastSDA, 0);
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i2c_master_wait(5);
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i2c_master_setDC(level, 0);
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i2c_master_wait(5); // sda level, scl 0
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i2c_master_setDC(level, 1);
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i2c_master_wait(8); // sda level, scl 1
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i2c_master_setDC(level, 0);
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i2c_master_wait(5); // sda level, scl 0
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i2c_master_setDC(1, 0);
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i2c_master_wait(5);
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}
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/******************************************************************************
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* FunctionName : i2c_master_getAck
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* Description : confirm if peer send ack
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* Parameters : NONE
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* Returns : uint8 - ack value, 0 or 1
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*******************************************************************************/
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uint8 ICACHE_FLASH_ATTR
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i2c_master_getAck(void)
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{
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uint8 retVal;
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i2c_master_setDC(m_nLastSDA, 0);
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i2c_master_wait(5);
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i2c_master_setDC(1, 0);
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i2c_master_wait(5);
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i2c_master_setDC(1, 1);
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i2c_master_wait(5);
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retVal = i2c_master_getDC();
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i2c_master_wait(5);
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i2c_master_setDC(1, 0);
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i2c_master_wait(5);
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return retVal;
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}
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/******************************************************************************
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* FunctionName : i2c_master_checkAck
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* Description : get dev response
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* Parameters : NONE
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* Returns : true : get ack ; false : get nack
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*******************************************************************************/
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bool ICACHE_FLASH_ATTR
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i2c_master_checkAck(void)
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{
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if(i2c_master_getAck()){
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return FALSE;
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}else{
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return TRUE;
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}
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}
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/******************************************************************************
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* FunctionName : i2c_master_send_ack
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* Description : response ack
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* Parameters : NONE
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* Returns : NONE
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*******************************************************************************/
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void ICACHE_FLASH_ATTR
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i2c_master_send_ack(void)
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{
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i2c_master_setAck(0x0);
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}
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/******************************************************************************
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* FunctionName : i2c_master_send_nack
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* Description : response nack
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* Parameters : NONE
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* Returns : NONE
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*******************************************************************************/
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void ICACHE_FLASH_ATTR
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i2c_master_send_nack(void)
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{
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i2c_master_setAck(0x1);
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}
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/******************************************************************************
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* FunctionName : i2c_master_readByte
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* Description : read Byte from i2c bus
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* Parameters : NONE
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* Returns : uint8 - readed value
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*******************************************************************************/
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uint8 ICACHE_FLASH_ATTR
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i2c_master_readByte(void)
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{
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uint8 retVal = 0;
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uint8 k, i;
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i2c_master_wait(5);
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i2c_master_setDC(m_nLastSDA, 0);
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i2c_master_wait(5); // sda 1, scl 0
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for (i = 0; i < 8; i++) {
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i2c_master_wait(5);
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i2c_master_setDC(1, 0);
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i2c_master_wait(5); // sda 1, scl 0
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i2c_master_setDC(1, 1);
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i2c_master_wait(5); // sda 1, scl 1
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k = i2c_master_getDC();
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i2c_master_wait(5);
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if (i == 7) {
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i2c_master_wait(3); ////
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}
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k <<= (7 - i);
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retVal |= k;
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}
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i2c_master_setDC(1, 0);
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i2c_master_wait(5); // sda 1, scl 0
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return retVal;
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}
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/******************************************************************************
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* FunctionName : i2c_master_writeByte
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* Description : write wrdata value(one byte) into i2c
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* Parameters : uint8 wrdata - write value
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* Returns : NONE
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*******************************************************************************/
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void ICACHE_FLASH_ATTR
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i2c_master_writeByte(uint8 wrdata)
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{
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uint8 dat;
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sint8 i;
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i2c_master_wait(5);
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i2c_master_setDC(m_nLastSDA, 0);
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i2c_master_wait(5);
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for (i = 7; i >= 0; i--) {
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dat = wrdata >> i;
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i2c_master_setDC(dat, 0);
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i2c_master_wait(5);
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i2c_master_setDC(dat, 1);
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i2c_master_wait(5);
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if (i == 0) {
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i2c_master_wait(3); ////
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}
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i2c_master_setDC(dat, 0);
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i2c_master_wait(5);
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}
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}
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