91 lines
2.1 KiB
C
91 lines
2.1 KiB
C
/*
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* Copyright (c) 2021 G-Technologies Sdn. Bhd.
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*
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* SPDX-License-Identifier: Apache-2.0
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*/
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#ifndef ZEPHYR_DRIVERS_SENSOR_MHZ19B_MHZ19B
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#define ZEPHYR_DRIVERS_SENSOR_MHZ19B_MHZ19B
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#include <kernel.h>
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#include <device.h>
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#include <drivers/uart.h>
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#define MHZ19B_BUF_LEN 9
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#define MHZ19B_TX_CMD_IDX 2
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#define MHZ19B_RX_CMD_IDX 1
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#define MHZ19B_CHECKSUM_IDX 8
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/* Arbitrary max duration to wait for the response */
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#define MHZ19B_WAIT K_SECONDS(1)
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enum mhz19b_cmd_idx {
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/* Command to poll for CO2 */
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MHZ19B_CMD_IDX_GET_CO2,
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/* Read range */
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MHZ19B_CMD_IDX_GET_RANGE,
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/* Get ABC status */
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MHZ19B_CMD_IDX_GET_ABC,
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/* Enable ABC */
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MHZ19B_CMD_IDX_SET_ABC_ON,
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/* Disable ABC */
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MHZ19B_CMD_IDX_SET_ABC_OFF,
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/* Set detection range to 2000 ppm */
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MHZ19B_CMD_IDX_SET_RANGE_2000,
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/* Set detection range to 5000 ppm */
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MHZ19B_CMD_IDX_SET_RANGE_5000,
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/* Set detection range to 10000 ppm */
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MHZ19B_CMD_IDX_SET_RANGE_10000,
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/* Number of supported commands */
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MHZ19B_CMD_IDX_MAX,
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};
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struct mhz19b_data {
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/* Max data length is 16 bits */
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uint16_t data;
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/* Command buf length is 9 */
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uint8_t xfer_bytes;
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bool has_rsp;
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uint8_t rd_data[MHZ19B_BUF_LEN];
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struct k_sem tx_sem;
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struct k_sem rx_sem;
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enum mhz19b_cmd_idx cmd_idx;
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};
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struct mhz19b_cfg {
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const struct device *uart_dev;
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uint16_t range;
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bool abc_on;
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uart_irq_callback_user_data_t cb;
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};
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#define MHZ19B_HEADER 0xff
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#define MHZ19B_RESERVED 0x01
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#define MHZ19B_NULL 0x00
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#define MHZ19B_NULL_1 MHZ19B_NULL
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#define MHZ19B_NULL_2 MHZ19B_NULL, MHZ19B_NULL_1
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#define MHZ19B_NULL_3 MHZ19B_NULL, MHZ19B_NULL_2
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#define MHZ19B_NULL_4 MHZ19B_NULL, MHZ19B_NULL_3
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#define MHZ19B_NULL_5 MHZ19B_NULL, MHZ19B_NULL_4
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#define MHZ19B_NULL_COUNT(c) MHZ19B_NULL_##c
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#define MHZ19B_ABC_ON 0xA0
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#define MHZ19B_ABC_OFF 0x00
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#define MHZ19B_RANGE_2000 0x07, 0xD0
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#define MHZ19B_RANGE_5000 0x13, 0x88
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#define MHZ19B_RANGE_10000 0x27, 0x10
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enum mhz19b_cmd {
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MHZ19B_CMD_SET_ABC = 0x79,
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MHZ19B_CMD_GET_ABC = 0x7D,
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MHZ19B_CMD_GET_CO2 = 0x86,
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MHZ19B_CMD_SET_RANGE = 0x99,
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MHZ19B_CMD_GET_RANGE = 0x9B,
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};
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#endif /* ZEPHYR_DRIVERS_SENSOR_MHZ19B_MHZ19B */
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