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custom delay

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lilian 2016-12-01 12:48:16 +01:00 • committed by lilian
parent 5eae1664e5
commit 11d34df273
1 changed files with 10 additions and 4 deletions
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14
extras/i2c/i2c.c
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@ -24,14 +24,13 @@
#include <esp8266.h> #include <esp8266.h>
#include <espressif/esp_misc.h> // sdk_os_delay_us #include <espressif/esp_misc.h> // sdk_os_delay_us
#include <espressif/esp_system.h>
#include "i2c.h" #include "i2c.h"
// I2C driver for ESP8266 written for use with esp-open-rtos // I2C driver for ESP8266 written for use with esp-open-rtos
// Based on https://en.wikipedia.org/wiki/I²C#Example_of_bit-banging_the_I.C2.B2C_Master_protocol // Based on https://en.wikipedia.org/wiki/I²C#Example_of_bit-banging_the_I.C2.B2C_Master_protocol
// With calling overhead, we end up at ~320kbit/s
// With calling overhead, we end up at ~100kbit/s
#define CLK_HALF_PERIOD_US (1)
#define CLK_STRETCH (10) #define CLK_STRETCH (10)
@ -59,7 +58,14 @@ void i2c_init(uint8_t scl_pin, uint8_t sda_pin)
static inline void i2c_delay(void) static inline void i2c_delay(void)
{ {
sdk_os_delay_us(CLK_HALF_PERIOD_US); if (sdk_system_get_cpu_freq() == SYS_CPU_160MHZ)
{
for (volatile uint8_t __j = 0 ; __j < 5 ; __j++) {} ;
}
else
{
for (volatile uint8_t __j = 0 ; __j < 0 ; __j++) {} ;
}
} }
// Set SCL as input, allowing it to float high, and return current // Set SCL as input, allowing it to float high, and return current