veml7700_sensor.h File Reference

I²C driver for the VEML7700 ambiant light sensor. More...

#include <stddef.h>
#include <stdint.h>
#include <string.h>
#include "i2c_bus.h"
#include "esp_err.h"
#include "esp_log.h"

Go to the source code of this file.

Data Structures
struct	veml7700_config_t
	Configuration structure for the VEML7700 sensor. More...
struct	veml7700_dev_t
	Device handle structure for the VEML7700 sensor. More...

Macros
#define	VEML7700_I2C_ADDR   (0x10)
	Default I²C address for VEML7700 sensors.
Integration Time Constants
Integration times for the VEML7700 sensor.
#define	VEML7700_INTEGRATION_TIME_25MS   (0b1100)
	25 ms
#define	VEML7700_INTEGRATION_TIME_50MS   (0b1000)
	50 ms
#define	VEML7700_INTEGRATION_TIME_100MS   (0b0000)
	100 ms
#define	VEML7700_INTEGRATION_TIME_200MS   (0b0001)
	200 ms
#define	VEML7700_INTEGRATION_TIME_400MS   (0b0010)
	400 ms
#define	VEML7700_INTEGRATION_TIME_800MS   (0b0011)
	800 ms
Gain Constants
Gain settings for the VEML7700 sensor.
#define	VEML7700_GAIN_1   (0b00)
	x1 gain
#define	VEML7700_GAIN_2   (0b01)
	x2 gain
#define	VEML7700_GAIN_DIV_8   (0b10)
	/8 gain
#define	VEML7700_GAIN_DIV_4   (0b11)
	/4 gain
Power Saving Mode Constants
Power saving modes for the sensor.
#define	VEML7700_POWER_SAVING_MODE_500MS   (0b00)
	500 ms interval
#define	VEML7700_POWER_SAVING_MODE_1000MS   (0b01)
	1000 ms interval
#define	VEML7700_POWER_SAVING_MODE_2000MS   (0b10)
	2000 ms interval
#define	VEML7700_POWER_SAVING_MODE_4000MS   (0b11)
	4000 ms interval
Persistence Protection Constants
Number of consecutive samples before triggering an interrupt.
#define	VEML7700_PERSISTENCE_PROTECTION_1   (0b00)
	1 sample
#define	VEML7700_PERSISTENCE_PROTECTION_2   (0b01)
	2 samples
#define	VEML7700_PERSISTENCE_PROTECTION_4   (0b10)
	4 samples
#define	VEML7700_PERSISTENCE_PROTECTION_8   (0b11)
	8 samples

Typedefs
typedef uint8_t	i2c_addr_t
	Type for I²C addresses.
typedef uint32_t	ill_lx_t
	Type for illuminance [lx].
typedef void *	veml7700_handle_t
	Opaque handle for a VEML7700 sensor.

Functions
veml7700_handle_t	veml7700_i2c_create (i2c_bus_handle_t bus, i2c_addr_t dev_addr)
	Create a VEML7700 device handle for I²C communication.
veml7700_handle_t	veml7700_i2c_init (i2c_bus_handle_t bus, i2c_addr_t dev_addr)
	Initialize the VEML7700 sensor over I²C.
void	veml7700_i2c_delete (veml7700_handle_t sensor)
	Deinitialize the VEML7700 sensor and free resources.
esp_err_t	veml7700_i2c_probe (veml7700_handle_t sensor)
	Probe if the sensor exist on the I²C bus.
esp_err_t	veml7700_i2c_write_config (veml7700_handle_t sensor, veml7700_config_t *cfg)
	Write the configuration to the sensor.
esp_err_t	veml7700_i2c_read_config (veml7700_handle_t sensor, veml7700_config_t *cfg)
	Read the sensor configuration.
esp_err_t	veml7700_i2c_read_ambient_light (veml7700_handle_t sensor, ill_lx_t *val)
	Read ambiant light value from the sensor.
esp_err_t	veml7700_i2c_read_white_channel (veml7700_handle_t sensor, ill_lx_t *val)
	Read white channel value from the sensor.
esp_err_t	veml7700_i2c_read_interrupt_status (veml7700_handle_t sensor, bool *low, bool *high)
	Read the interrupt status from the sensor.

Detailed Description

I²C driver for the VEML7700 ambiant light sensor.

Author

Adrien Chevrier

Copyright

• Portions under ISC license, derived from:
  • Copyright (c) 2022 Marc Luehr.

• Modifications and rewrite for new I²C interface:
  • Copyright (c) 2026 Adrien Chevrier. Under AGPL-3.0-or-later license.

This program is free software: you can redistribute it and/or modify it under the terms of the GNU Affero General Public License as published by the Free Software Foundation, either version 3 of the License, or any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Affero General Public License for more details.

You should have received a copy of the GNU Affero General Public License along with this program. If not, see https://www.gnu.org/licenses/.

Version

0.1

Date

2026-02-04