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reduce speed of i2c master bus reset routine and release sda

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jeremy 2018-09-30 19:26:09 +10:00 committed by morris
parent fe19ea977b
commit b810b32675
1 changed files with 12 additions and 3 deletions
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15
components/driver/i2c.c
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@ -541,14 +541,23 @@ static esp_err_t i2c_master_clear_bus(i2c_port_t i2c_num)
// because after some serious interference, the bus may keep high all the time and the i2c bus is out of service.
gpio_set_direction(scl_io, GPIO_MODE_OUTPUT_OD);
gpio_set_direction(sda_io, GPIO_MODE_OUTPUT_OD);
gpio_set_level(scl_io, 1);
int scl_half_period = 5; // use standard 100kHz data rate
gpio_set_level(sda_io, 1);
gpio_set_level(sda_io, 0);
ets_delay_us(scl_half_period);
gpio_set_level(scl_io, 1);
ets_delay_us(scl_half_period);
for (int i = 0; i < 9; i++) {
gpio_set_level(scl_io, 0);
ets_delay_us(scl_half_period);
gpio_set_level(scl_io, 1);
ets_delay_us(scl_half_period);
}
gpio_set_level(sda_io, 1);
gpio_set_level(sda_io, 0); // setup stop condition (this is an implicit start condition)
ets_delay_us(scl_half_period);
gpio_set_level(sda_io, 1); // generate stop condition
ets_delay_us(scl_half_period);
i2c_set_pin(i2c_num, sda_io, scl_io, 1, 1, I2C_MODE_MASTER);
return ESP_OK;
}