1 /* 2 * Copyright (c) 2021 G-Technologies Sdn. Bhd. 3 * 4 * SPDX-License-Identifier: Apache-2.0 5 */ 6 7 #ifndef ZEPHYR_DRIVERS_SENSOR_MHZ19B_MHZ19B 8 #define ZEPHYR_DRIVERS_SENSOR_MHZ19B_MHZ19B 9 10 #include <zephyr/kernel.h> 11 #include <zephyr/device.h> 12 #include <zephyr/drivers/uart.h> 13 14 #define MHZ19B_BUF_LEN 9 15 16 #define MHZ19B_TX_CMD_IDX 2 17 #define MHZ19B_RX_CMD_IDX 1 18 #define MHZ19B_CHECKSUM_IDX 8 19 20 /* Arbitrary max duration to wait for the response */ 21 #define MHZ19B_WAIT K_SECONDS(1) 22 23 enum mhz19b_cmd_idx { 24 /* Command to poll for CO2 */ 25 MHZ19B_CMD_IDX_GET_CO2, 26 /* Read range */ 27 MHZ19B_CMD_IDX_GET_RANGE, 28 /* Get ABC status */ 29 MHZ19B_CMD_IDX_GET_ABC, 30 /* Enable ABC */ 31 MHZ19B_CMD_IDX_SET_ABC_ON, 32 /* Disable ABC */ 33 MHZ19B_CMD_IDX_SET_ABC_OFF, 34 /* Set detection range to 2000 ppm */ 35 MHZ19B_CMD_IDX_SET_RANGE_2000, 36 /* Set detection range to 5000 ppm */ 37 MHZ19B_CMD_IDX_SET_RANGE_5000, 38 /* Set detection range to 10000 ppm */ 39 MHZ19B_CMD_IDX_SET_RANGE_10000, 40 /* Number of supported commands */ 41 MHZ19B_CMD_IDX_MAX, 42 }; 43 44 struct mhz19b_data { 45 /* Max data length is 16 bits */ 46 uint16_t data; 47 /* Command buf length is 9 */ 48 uint8_t xfer_bytes; 49 bool has_rsp; 50 51 uint8_t rd_data[MHZ19B_BUF_LEN]; 52 53 struct k_sem tx_sem; 54 struct k_sem rx_sem; 55 56 enum mhz19b_cmd_idx cmd_idx; 57 }; 58 59 struct mhz19b_cfg { 60 const struct device *uart_dev; 61 uint16_t range; 62 bool abc_on; 63 uart_irq_callback_user_data_t cb; 64 }; 65 66 #define MHZ19B_HEADER 0xff 67 #define MHZ19B_RESERVED 0x01 68 #define MHZ19B_NULL 0x00 69 #define MHZ19B_NULL_1 MHZ19B_NULL 70 #define MHZ19B_NULL_2 MHZ19B_NULL, MHZ19B_NULL_1 71 #define MHZ19B_NULL_3 MHZ19B_NULL, MHZ19B_NULL_2 72 #define MHZ19B_NULL_4 MHZ19B_NULL, MHZ19B_NULL_3 73 #define MHZ19B_NULL_5 MHZ19B_NULL, MHZ19B_NULL_4 74 #define MHZ19B_NULL_COUNT(c) MHZ19B_NULL_##c 75 76 #define MHZ19B_ABC_ON 0xA0 77 #define MHZ19B_ABC_OFF 0x00 78 #define MHZ19B_RANGE_2000 0x07, 0xD0 79 #define MHZ19B_RANGE_5000 0x13, 0x88 80 #define MHZ19B_RANGE_10000 0x27, 0x10 81 82 enum mhz19b_cmd { 83 MHZ19B_CMD_SET_ABC = 0x79, 84 MHZ19B_CMD_GET_ABC = 0x7D, 85 MHZ19B_CMD_GET_CO2 = 0x86, 86 MHZ19B_CMD_SET_RANGE = 0x99, 87 MHZ19B_CMD_GET_RANGE = 0x9B, 88 }; 89 90 #endif /* ZEPHYR_DRIVERS_SENSOR_MHZ19B_MHZ19B */ 91
