sps30/sps30.c

/*
 * File:        sps30.c
 * Description: Sensirion SPS30 sensor communication library
 * Author:      David Zaitlik
 * Date:        2021-07-18
 *
 *
 * Copyright (c) 2024 Veles Labs s.r.o.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in all
 * copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 *
 */

#include "sps30.h"

/*
 * Functions to be implemented by user
 */

/* I2C */
int8_t sps30_i2c_transmit(uint8_t address, uint8_t *buffer, int len) __attribute__((weak));
int8_t sps30_i2c_receive(uint8_t address, uint8_t *buffer, int len) __attribute__((weak));
/* CRC */
uint8_t sensirion_crc8_calculate(const uint8_t *data, uint16_t count) __attribute__((weak));
/* Interrupts */
int8_t sps30_disable_interrupts(void) __attribute__((weak));
int8_t sps30_enable_interrupts(void) __attribute__((weak));
/* delay function */
void delay_ms(int delay_ms) __attribute__((weak));

/*
 * Public functions
 */

int8_t sps30_send_cmd(sps30_cmd_t cmd)
{
	uint8_t buffer[32];
	uint8_t result;

	// start measurement
	buffer[0] = cmd >> 8;
	buffer[1] = cmd & 0x00ff;
	sps30_disable_interrupts();
	result = sps30_i2c_transmit(SPS30_I2C_ADDRESS<<1, buffer, 2);
	sps30_enable_interrupts();
	// TODO: Proc to vraci NACK? Vyresit.
	if (result != 0) {
		return SPS30_ERROR;
	}

	return SPS30_OK;
}

int8_t sps30_start_measurement( void )
{
	uint8_t buffer[5];
	uint8_t result;

	buffer[0] = SPS30_START_MEASUREMENT >> 8;
	buffer[1] = SPS30_START_MEASUREMENT & 0x00ff;
	buffer[2] = SPS30_UINT16_FORMAT;
	buffer[3] = 0x00;
	buffer[4] = sensirion_crc8_calculate(buffer + 2, 2);

	sps30_disable_interrupts();
	result = sps30_i2c_transmit(SPS30_I2C_ADDRESS<<1, buffer, 5);
	sps30_enable_interrupts();

	if (result != 0) {
		return SPS30_ERROR;
	}
	return SPS30_OK;
}

int8_t sps30_stop_measurement( void )
{
	return sps30_send_cmd(SPS30_STOP_MEASUREMENT);
}

int8_t sps30_read_measured_values(sps30_data_t *measured_data)
{
	uint8_t buffer[32];

	uint8_t result;

	/* start measurement */
	buffer[0] = SPS30_READ_MEASURED_VALUES >> 8;
	buffer[1] = SPS30_READ_MEASURED_VALUES & 0xFF;
	sps30_disable_interrupts();
	result = sps30_i2c_transmit(SPS30_I2C_ADDRESS<<1, buffer, 2);
	sps30_enable_interrupts();
	if (result != 0) {
		return SPS30_ERROR;
	}
	delay_ms(10);
	/* read out */
	sps30_disable_interrupts();
	result = sps30_i2c_receive(SPS30_I2C_ADDRESS<<1, buffer, 3 * SPS30_MEASURED_VALUES_COUNT);
	sps30_enable_interrupts();
	if (result != 0)
	{
		return SPS30_ERROR;
	}
	/* check data integrity */
	for (uint8_t i = 0; i < SPS30_MEASURED_VALUES_COUNT; i++)
	{
		uint8_t checksum_calculated = sensirion_crc8_calculate(buffer + 3*i, 2);
		uint8_t checksum_received = buffer[3*i + 2];
		if (checksum_calculated != checksum_received) {
			return SPS30_CRC8_ERROR;
		}
	}
	/* copy to output struct */
	/* mass concencration [ug / m^3] */
	int pos = 0;
	for (int i = 0; i < 4; i++) {
		/* i + 1 because mass concentration starts at PM1.0 (there is no PM0.5) */
		measured_data->mass_concentration[i + 1] = (buffer[pos] << 8) + buffer[pos + 1];
		pos += 3; /* 2 B data, 1 B crc */
	}
	/* number concentration [1 / cm^3] */
	for (int i = 0; i < 5; i++) {
		measured_data->number_concentration[i] = (buffer[pos] << 8) + buffer[pos + 1];
		pos += 3;
	}
	/* typical particle size [nm] */
	measured_data->typical_particle_size = (buffer[pos] << 8) + buffer[pos + 1];

	return SPS30_OK;
}

int8_t sps30_sleep( void )
{
	return sps30_send_cmd(SPS30_SLEEP);
}

int8_t sps30_wake_up( void )
{
	return sps30_send_cmd(SPS30_WAKE_UP);
}

int8_t sps30_start_fan_cleaning( void )
{
	return sps30_send_cmd(SPS30_START_FAN_CLEANING);
}

int8_t sps30_reset( void )
{
	return sps30_send_cmd(SPS30_RESET);
}

int8_t sps30_read_status_register ( void )
{
	uint8_t buffer[6];

	uint8_t result;

	/* start measurement */
	buffer[0] = SPS30_READ_DEVICE_STATUS_REGISTER >> 8;
	buffer[1] = SPS30_READ_DEVICE_STATUS_REGISTER & 0x00ff;
	sps30_disable_interrupts();
	result = sps30_i2c_transmit(SPS30_I2C_ADDRESS<<1, buffer, 2);
	sps30_enable_interrupts();
	if (result != 0) {
		return SPS30_ERROR;
	}
	delay_ms(10);
	/* read out */
	sps30_disable_interrupts();
	result = sps30_i2c_receive(SPS30_I2C_ADDRESS<<1, buffer, 6);
	sps30_enable_interrupts();
	// TODO

	return SPS30_OK;
}

int8_t sps30_read_firmware_version ( uint8_t * fw_ver_hi, uint8_t * fw_ver_lo )
{
	uint8_t i2c_tx_buffer[2];
	uint8_t i2c_rx_buffer[3];

	uint8_t result;

	/* start measurement */
	i2c_tx_buffer[0] = SPS30_READ_VERSION >> 8;
	i2c_tx_buffer[1] = SPS30_READ_VERSION & 0x00ff;
	sps30_disable_interrupts();
	result = sps30_i2c_transmit(SPS30_I2C_ADDRESS<<1, i2c_tx_buffer, 2);
	sps30_enable_interrupts();

	// TODO: Proc to vraci NACK? Vyresit.
	if (result != 0) {
		// return SPS30_ERROR;
	}

	delay_ms(1);
	/* read out */
	sps30_disable_interrupts();
	result = sps30_i2c_receive(SPS30_I2C_ADDRESS<<1, i2c_rx_buffer, 3);
	sps30_enable_interrupts();
	if (result != 0)
	{
		// return SPS30_ERROR;
	}

	*fw_ver_hi = i2c_rx_buffer[0];
	*fw_ver_lo = i2c_rx_buffer[1];

	return SPS30_OK;
}