From 33a03fd31f37c343712bfa2b877891397743139c Mon Sep 17 00:00:00 2001 From: David Antliff Date: Fri, 4 Aug 2017 16:49:09 +1200 Subject: [PATCH] Add support for multiple devices on single 1-Wire bus. --- main/ds18b20.c | 232 ++++++++-------- main/ds18b20_main.c | 91 +++++-- main/ds18b20_static.h | 8 +- main/owb.c | 610 ++++++++++++++++++++++++++---------------- main/owb.h | 23 +- main/owb_static.h | 8 +- 6 files changed, 591 insertions(+), 381 deletions(-) diff --git a/main/ds18b20.c b/main/ds18b20.c index 14d54e6..2c4113f 100644 --- a/main/ds18b20.c +++ b/main/ds18b20.c @@ -29,143 +29,145 @@ struct _DS18B20_Info { - bool init; - bool use_crc; - OneWireBus * bus; - uint64_t rom_code; + bool init; + bool use_crc; + OneWireBus * bus; + uint64_t rom_code; }; static bool _is_init(const DS18B20_Info * ds18b20_info) { - bool ok = false; - if (ds18b20_info != NULL) - { - if (ds18b20_info->init) - { - // OK - ok = true; - } - else - { - ESP_LOGE(TAG, "ds18b20_info is not initialised"); - } - } - else - { - ESP_LOGE(TAG, "ds18b20_info is NULL"); - } - return ok; + bool ok = false; + if (ds18b20_info != NULL) + { + if (ds18b20_info->init) + { + // OK + ok = true; + } + else + { + ESP_LOGE(TAG, "ds18b20_info is not initialised"); + } + } + else + { + ESP_LOGE(TAG, "ds18b20_info is NULL"); + } + return ok; } DS18B20_Info * ds18b20_malloc(void) { - DS18B20_Info * ds18b20_info = malloc(sizeof(*ds18b20_info)); - if (ds18b20_info != NULL) - { - memset(ds18b20_info, 0, sizeof(*ds18b20_info)); - ESP_LOGD(TAG, "malloc %p", ds18b20_info); - } - else - { - ESP_LOGE(TAG, "malloc failed"); - } - - return ds18b20_info; + DS18B20_Info * ds18b20_info = malloc(sizeof(*ds18b20_info)); + if (ds18b20_info != NULL) + { + memset(ds18b20_info, 0, sizeof(*ds18b20_info)); + ESP_LOGD(TAG, "malloc %p", ds18b20_info); + } + else + { + ESP_LOGE(TAG, "malloc failed"); + } + + return ds18b20_info; } void ds18b20_free(DS18B20_Info ** ds18b20_info) { - if (ds18b20_info != NULL && (*ds18b20_info != NULL)) - { - ESP_LOGD(TAG, "free %p", *ds18b20_info); - free(*ds18b20_info); - *ds18b20_info = NULL; - } + if (ds18b20_info != NULL && (*ds18b20_info != NULL)) + { + ESP_LOGD(TAG, "free %p", *ds18b20_info); + free(*ds18b20_info); + *ds18b20_info = NULL; + } } void ds18b20_init(DS18B20_Info * ds18b20_info, OneWireBus * bus, uint64_t rom_code) { - if (ds18b20_info != NULL) - { - ds18b20_info->bus = bus; - ds18b20_info->rom_code = rom_code; - ds18b20_info->use_crc = false; - ds18b20_info->init = true; - } - else - { - ESP_LOGE(TAG, "ds18b20_info is NULL"); - } + if (ds18b20_info != NULL) + { + ds18b20_info->bus = bus; + ds18b20_info->rom_code = rom_code; + ds18b20_info->use_crc = false; + ds18b20_info->init = true; + } + else + { + ESP_LOGE(TAG, "ds18b20_info is NULL"); + } } void ds18b20_use_crc(DS18B20_Info * ds18b20_info, bool use_crc) { - if (_is_init(ds18b20_info)) - { - ds18b20_info->use_crc = use_crc; - ESP_LOGD(TAG, "use_crc %d", ds18b20_info->use_crc); - } + if (_is_init(ds18b20_info)) + { + ds18b20_info->use_crc = use_crc; + ESP_LOGD(TAG, "use_crc %d", ds18b20_info->use_crc); + } } float ds18b20_get_temp(DS18B20_Info * ds18b20_info) { - float temp = 0.0f; - if (_is_init(ds18b20_info)) - { - OneWireBus * bus = ds18b20_info->bus; - if (owb_reset(bus)) - { - //owb_write_byte(bus, OWB_ROM_SKIP); - owb_write_byte(bus, OWB_ROM_MATCH); - owb_write_rom_code(bus, ds18b20_info->rom_code); - owb_write_byte(bus, DS18B20_FUNCTION_TEMP_CONVERT); - vTaskDelay(750 / portTICK_PERIOD_MS); - - // reset - owb_reset(bus); - owb_write_byte(bus, OWB_ROM_SKIP); - owb_write_byte(bus, DS18B20_FUNCTION_SCRATCHPAD_READ); - - uint8_t temp_LSB = 0; - uint8_t temp_MSB = 0; - if (ds18b20_info->use_crc) - { - // Without CRC: - temp_LSB = owb_read_byte(bus); - temp_MSB = owb_read_byte(bus); - owb_reset(bus); // terminate early - } - else - { - // with CRC: - uint8_t buffer[9]; - owb_read_bytes(bus, buffer, 9); - - temp_LSB = buffer[0]; - temp_MSB = buffer[1]; - - uint8_t crc = 0; - for (int i = 0; i < 9; ++i) - { - crc = owb_crc8(crc, buffer[i]); - } - ESP_LOGD(TAG, "crc 0x%02x", crc); - - if (crc != 0) - { - ESP_LOGE(TAG, "CRC failed"); - temp_LSB = temp_MSB = 0; - } - } - - ESP_LOGD(TAG, "temp_LSB 0x%02x, temp_MSB 0x%02x", temp_LSB, temp_MSB); - temp = (float)(((temp_MSB << 8) + temp_LSB) >> 4); - } - else - { - ESP_LOGE(TAG, "ds18b20 device not responding"); - } - } - - return temp; + float temp = 0.0f; + if (_is_init(ds18b20_info)) + { + OneWireBus * bus = ds18b20_info->bus; + if (owb_reset(bus)) + { + //owb_write_byte(bus, OWB_ROM_SKIP); + owb_write_byte(bus, OWB_ROM_MATCH); + owb_write_rom_code(bus, ds18b20_info->rom_code); + owb_write_byte(bus, DS18B20_FUNCTION_TEMP_CONVERT); + vTaskDelay(750 / portTICK_PERIOD_MS); + + // reset + owb_reset(bus); + //owb_write_byte(bus, OWB_ROM_SKIP); + owb_write_byte(bus, OWB_ROM_MATCH); + owb_write_rom_code(bus, ds18b20_info->rom_code); + owb_write_byte(bus, DS18B20_FUNCTION_SCRATCHPAD_READ); + + uint8_t temp_LSB = 0; + uint8_t temp_MSB = 0; + if (ds18b20_info->use_crc) + { + // Without CRC: + temp_LSB = owb_read_byte(bus); + temp_MSB = owb_read_byte(bus); + owb_reset(bus); // terminate early + } + else + { + // with CRC: + uint8_t buffer[9]; + owb_read_bytes(bus, buffer, 9); + + temp_LSB = buffer[0]; + temp_MSB = buffer[1]; + + uint8_t crc = 0; + for (int i = 0; i < 9; ++i) + { + crc = owb_crc8(crc, buffer[i]); + } + ESP_LOGD(TAG, "crc 0x%02x", crc); + + if (crc != 0) + { + ESP_LOGE(TAG, "CRC failed"); + temp_LSB = temp_MSB = 0; + } + } + + ESP_LOGD(TAG, "temp_LSB 0x%02x, temp_MSB 0x%02x", temp_LSB, temp_MSB); + temp = (float)(((temp_MSB << 8) + temp_LSB) >> 4); + } + else + { + ESP_LOGE(TAG, "ds18b20 device not responding"); + } + } + + return temp; } diff --git a/main/ds18b20_main.c b/main/ds18b20_main.c index b7d5573..f7aa57f 100644 --- a/main/ds18b20_main.c +++ b/main/ds18b20_main.c @@ -4,6 +4,7 @@ #include "freertos/task.h" #include "esp_system.h" +// Uncomment to enable static (stack-based) allocation of instances and avoid malloc/free. //#define USE_STATIC 1 #ifdef USE_STATIC @@ -16,44 +17,90 @@ #define GPIO_DS18B20_0 (GPIO_NUM_4) +#define MAX_DEVICES (8) void app_main() { - // Create a 1-Wire bus + // Create a 1-Wire bus #ifdef USE_STATIC - OneWireBus_Static owb_static; // static allocation - OneWireBus * owb = &owb_static; + OneWireBus_Static owb_static; // static allocation + OneWireBus * owb = &owb_static; #else - OneWireBus * owb = owb_malloc(); // heap allocation + OneWireBus * owb = owb_malloc(); // heap allocation #endif - owb_init(owb, GPIO_DS18B20_0); + owb_init(owb, GPIO_DS18B20_0); owb_use_crc(owb, true); // enable CRC check for ROM code - //owb_search(); // find all connected devices - //OneWireBusROMCode rom_code = 0x1162e87ccee28; - uint64_t rom_code = owb_read_rom(owb); - printf("1-Wire ROM code 0x%08" PRIx64 "\n", rom_code); + // find all connected devices + uint8_t device_rom_codes[8][MAX_DEVICES] = {0}; + int num_devices = 0; + OneWireBus_SearchState search_state = {0}; + bool found = owb_search_first(owb, &search_state); + while (found) + { + printf("Device %d found: ", num_devices); + for (int i = 7; i >= 0; i--) + { + device_rom_codes[num_devices][i] = search_state.rom_code[i]; + printf("%02x", search_state.rom_code[i]); + } + printf("\n"); + ++num_devices; + found = owb_search_next(owb, &search_state); + } + + //uint64_t rom_code = 0x0001162e87ccee28; // pink + //uint64_t rom_code = 0xf402162c6149ee28; // green + //uint64_t rom_code = 0x1502162ca5b2ee28; // orange + //uint64_t rom_code = owb_read_rom(owb); + //printf("1-Wire ROM code 0x%08" PRIx64 "\n", rom_code); - // Create a DS18B20 device on the 1-Wire bus + // Create a DS18B20 device on the 1-Wire bus #ifdef USE_STATIC - DS18B20_Info_Static ds18b20_info_static; // static allocation - DS18B20_Info * ds18b20_info = &ds18b20_info_static; + DS18B20_Info_Static ds18b20_info_static; // static allocation + DS18B20_Info * ds18b20_info = &ds18b20_info_static; + DS18B20_Info devices_static[MAX_DEVICES] = {0}; + DS18B20_Info * devices[MAX_DEVICES] = {0}; + for (int i = 0; i < MAX_DEVICES; ++i) + { + devices[i] = &(devices_static[i]); + } #else - DS18B20_Info * ds18b20_info = ds18b20_malloc(); // heap allocation + DS18B20_Info * ds18b20_info = ds18b20_malloc(); // heap allocation + DS18B20_Info * devices[MAX_DEVICES] = {0}; #endif - ds18b20_init(ds18b20_info, owb, rom_code); // associate with bus and device - //ds18b20_init_solo(ds18b20_info, owb); // only one device on bus - ds18b20_use_crc(ds18b20_info, true); // enable CRC check for temperature readings + for (int i = 0; i < num_devices; ++i) + { +#ifdef USE_STATIC + DS18B20_Info * ds18b20_info = devices[i]; +#else + DS18B20_Info * ds18b20_info = ds18b20_malloc(); // heap allocation + devices[i] = ds18b20_info; +#endif + uint64_t rom_code = 0; + for (int j = 7; j >= 0; --j) + { + rom_code |= ((uint64_t)device_rom_codes[i][j] << (8 * j)); + } + printf("1-Wire ROM code 0x%08" PRIx64 "\n", rom_code); + + ds18b20_init(ds18b20_info, owb, rom_code); // associate with bus and device + //ds18b20_init_solo(ds18b20_info, owb); // only one device on bus + ds18b20_use_crc(ds18b20_info, true); // enable CRC check for temperature readings + } - while (1) - { - float temp = ds18b20_get_temp(ds18b20_info); - printf("Temp %.1f degrees C\n", temp); + while (1) + { + for (int i = 0; i < num_devices; ++i) + { + float temp = ds18b20_get_temp(devices[i]); + printf("Temp %d: %.1f degrees C\n", i, temp); + } vTaskDelay(1000 / portTICK_PERIOD_MS); - } + } for (int i = 10; i >= 0; i--) { printf("Restarting in %d seconds...\n", i); @@ -61,7 +108,7 @@ void app_main() } ds18b20_free(&ds18b20_info); - owb_free(&owb); + owb_free(&owb); printf("Restarting now.\n"); fflush(stdout); diff --git a/main/ds18b20_static.h b/main/ds18b20_static.h index 3501098..ed7d6e3 100644 --- a/main/ds18b20_static.h +++ b/main/ds18b20_static.h @@ -14,10 +14,10 @@ extern "C" { struct _DS18B20_Info { - bool init; - bool use_crc; - OneWireBus * bus; - uint64_t rom_code; + bool init; + bool use_crc; + OneWireBus * bus; + uint64_t rom_code; }; typedef struct _DS18B20_Info DS18B20_Info_Static; diff --git a/main/owb.c b/main/owb.c index 1fba20b..50b025a 100644 --- a/main/owb.c +++ b/main/owb.c @@ -12,64 +12,54 @@ #define TAG "owb" - struct _OneWireBus_Timing { - int A, B, C, D, E, F, G, H, I, J; + int A, B, C, D, E, F, G, H, I, J; }; // 1-Wire timing delays (standard) in ticks (quarter-microseconds). static const struct _OneWireBus_Timing _StandardTiming = { - 6 * 4, - 64 * 4, - 60 * 4, - 10 * 4, - 9 * 4, - 55 * 4, - 0, // G - 480 * 4, // H - 70 * 4, // I - 410 * 4, // J + 6 * 4, + 64 * 4, + 60 * 4, + 10 * 4, + 9 * 4, + 55 * 4, + 0, // G + 480 * 4, // H + 70 * 4, // I + 410 * 4, // J }; -//struct _OneWireBus -//{ -// bool init; -// int gpio; -// const struct _OneWireBus_Timing * timing; -// bool use_crc; -//}; - static void _tick_delay(int ticks) { - // Each tick is 0.25 microseconds. - float time_us = ticks / 4.0; - ets_delay_us(time_us); + // Each tick is 0.25 microseconds. + float time_us = ticks / 4.0; + ets_delay_us(time_us); } -static bool _is_init(const OneWireBus * bus) +bool _is_init(const OneWireBus * bus) { - bool ok = false; - if (bus != NULL) - { - if (bus->init) - { - // OK - ok = true; - } - else - { - ESP_LOGE(TAG, "bus is not initialised"); - } - } - else - { - ESP_LOGE(TAG, "bus is NULL"); - } - return ok; + bool ok = false; + if (bus != NULL) + { + if (bus->init) + { + // OK + ok = true; + } + else + { + ESP_LOGE(TAG, "bus is not initialised"); + } + } + else + { + ESP_LOGE(TAG, "bus is NULL"); + } + return ok; } - /** * @brief Generate a 1-Wire reset. * @param[in] bus Initialised bus instance. @@ -77,26 +67,26 @@ static bool _is_init(const OneWireBus * bus) */ static bool _reset(const OneWireBus * bus) { - bool present = false; - if (_is_init(bus)) - { - gpio_set_direction(bus->gpio, GPIO_MODE_OUTPUT); - - _tick_delay(bus->timing->G); - gpio_set_level(bus->gpio, 0); // Drive DQ low - _tick_delay(bus->timing->H); - gpio_set_level(bus->gpio, 1); // Release the bus - _tick_delay(bus->timing->I); - - gpio_set_direction(bus->gpio, GPIO_MODE_INPUT); - int level1 = gpio_get_level(bus->gpio); - _tick_delay(bus->timing->J); // Complete the reset sequence recovery - int level2 = gpio_get_level(bus->gpio); - - present = (level1 == 0) && (level2 == 1); // Sample for presence pulse from slave - ESP_LOGD(TAG, "reset: level1 0x%x, level2 0x%x, present %d", level1, level2, present); - } - return present; + bool present = false; + if (_is_init(bus)) + { + gpio_set_direction(bus->gpio, GPIO_MODE_OUTPUT); + + _tick_delay(bus->timing->G); + gpio_set_level(bus->gpio, 0); // Drive DQ low + _tick_delay(bus->timing->H); + gpio_set_level(bus->gpio, 1); // Release the bus + _tick_delay(bus->timing->I); + + gpio_set_direction(bus->gpio, GPIO_MODE_INPUT); + int level1 = gpio_get_level(bus->gpio); + _tick_delay(bus->timing->J); // Complete the reset sequence recovery + int level2 = gpio_get_level(bus->gpio); + + present = (level1 == 0) && (level2 == 1); // Sample for presence pulse from slave + ESP_LOGD(TAG, "reset: level1 0x%x, level2 0x%x, present %d", level1, level2, present); + } + return present; } /** @@ -106,16 +96,16 @@ static bool _reset(const OneWireBus * bus) */ static void _write_bit(const OneWireBus * bus, int bit) { - if (_is_init(bus)) - { - int delay1 = bit ? bus->timing->A : bus->timing->C; - int delay2 = bit ? bus->timing->B : bus->timing->D; - gpio_set_direction(bus->gpio, GPIO_MODE_OUTPUT); - gpio_set_level(bus->gpio, 0); // Drive DQ low - _tick_delay(delay1); - gpio_set_level(bus->gpio, 1); // Release the bus - _tick_delay(delay2); - } + if (_is_init(bus)) + { + int delay1 = bit ? bus->timing->A : bus->timing->C; + int delay2 = bit ? bus->timing->B : bus->timing->D; + gpio_set_direction(bus->gpio, GPIO_MODE_OUTPUT); + gpio_set_level(bus->gpio, 0); // Drive DQ low + _tick_delay(delay1); + gpio_set_level(bus->gpio, 1); // Release the bus + _tick_delay(delay2); + } } /** @@ -124,21 +114,21 @@ static void _write_bit(const OneWireBus * bus, int bit) */ static int _read_bit(const OneWireBus * bus) { - int result = 0; - if (_is_init(bus)) - { - gpio_set_direction(bus->gpio, GPIO_MODE_OUTPUT); - gpio_set_level(bus->gpio, 0); // Drive DQ low - _tick_delay(bus->timing->A); - gpio_set_level(bus->gpio, 1); // Release the bus - _tick_delay(bus->timing->E); - - gpio_set_direction(bus->gpio, GPIO_MODE_INPUT); - int level = gpio_get_level(bus->gpio); - _tick_delay(bus->timing->F); // Complete the timeslot and 10us recovery - result = level & 0x01; - } - return result; + int result = 0; + if (_is_init(bus)) + { + gpio_set_direction(bus->gpio, GPIO_MODE_OUTPUT); + gpio_set_level(bus->gpio, 0); // Drive DQ low + _tick_delay(bus->timing->A); + gpio_set_level(bus->gpio, 1); // Release the bus + _tick_delay(bus->timing->E); + + gpio_set_direction(bus->gpio, GPIO_MODE_INPUT); + int level = gpio_get_level(bus->gpio); + _tick_delay(bus->timing->F); // Complete the timeslot and 10us recovery + result = level & 0x01; + } + return result; } /** @@ -148,15 +138,15 @@ static int _read_bit(const OneWireBus * bus) */ static void _write_byte(const OneWireBus * bus, uint8_t data) { - if (_is_init(bus)) - { - ESP_LOGD(TAG, "write 0x%02x", data); - for (int i = 0; i < 8; ++i) - { - _write_bit(bus, data & 0x01); - data >>= 1; - } - } + if (_is_init(bus)) + { + ESP_LOGD(TAG, "write 0x%02x", data); + for (int i = 0; i < 8; ++i) + { + _write_bit(bus, data & 0x01); + data >>= 1; + } + } } /** @@ -166,20 +156,20 @@ static void _write_byte(const OneWireBus * bus, uint8_t data) */ static uint8_t _read_byte(const OneWireBus * bus) { - uint8_t result = 0; - if (_is_init(bus)) - { - for (int i = 0; i < 8; ++i) - { - result >>= 1; - if (_read_bit(bus)) - { - result |= 0x80; - } - } - ESP_LOGD(TAG, "read 0x%02x", result); - } - return result; + uint8_t result = 0; + if (_is_init(bus)) + { + for (int i = 0; i < 8; ++i) + { + result >>= 1; + if (_read_bit(bus)) + { + result |= 0x80; + } + } + ESP_LOGD(TAG, "read 0x%02x", result); + } + return result; } /** @@ -191,11 +181,11 @@ static uint8_t _read_byte(const OneWireBus * bus) */ static uint8_t * _read_block(const OneWireBus * bus, uint8_t * buffer, unsigned int len) { - for (int i = 0; i < len; ++i) - { - *buffer++ = _read_byte(bus); - } - return buffer; + for (int i = 0; i < len; ++i) + { + *buffer++ = _read_byte(bus); + } + return buffer; } /** @@ -207,11 +197,11 @@ static uint8_t * _read_block(const OneWireBus * bus, uint8_t * buffer, unsigned */ static const uint8_t * _write_block(const OneWireBus * bus, const uint8_t * buffer, unsigned int len) { - for (int i = 0; i < len; ++i) - { - _write_byte(bus, buffer[i]); - } - return buffer; + for (int i = 0; i < len; ++i) + { + _write_byte(bus, buffer[i]); + } + return buffer; } /** @@ -222,27 +212,148 @@ static const uint8_t * _write_block(const OneWireBus * bus, const uint8_t * buff */ static uint8_t _calc_crc(uint8_t crc, uint8_t data) { - // https://www.maximintegrated.com/en/app-notes/index.mvp/id/27 - static const uint8_t table[256] = { - 0, 94, 188, 226, 97, 63, 221, 131, 194, 156, 126, 32, 163, 253, 31, 65, - 157, 195, 33, 127, 252, 162, 64, 30, 95, 1, 227, 189, 62, 96, 130, 220, - 35, 125, 159, 193, 66, 28, 254, 160, 225, 191, 93, 3, 128, 222, 60, 98, - 190, 224, 2, 92, 223, 129, 99, 61, 124, 34, 192, 158, 29, 67, 161, 255, - 70, 24, 250, 164, 39, 121, 155, 197, 132, 218, 56, 102, 229, 187, 89, 7, - 219, 133, 103, 57, 186, 228, 6, 88, 25, 71, 165, 251, 120, 38, 196, 154, - 101, 59, 217, 135, 4, 90, 184, 230, 167, 249, 27, 69, 198, 152, 122, 36, - 248, 166, 68, 26, 153, 199, 37, 123, 58, 100, 134, 216, 91, 5, 231, 185, - 140, 210, 48, 110, 237, 179, 81, 15, 78, 16, 242, 172, 47, 113, 147, 205, - 17, 79, 173, 243, 112, 46, 204, 146, 211, 141, 111, 49, 178, 236, 14, 80, - 175, 241, 19, 77, 206, 144, 114, 44, 109, 51, 209, 143, 12, 82, 176, 238, - 50, 108, 142, 208, 83, 13, 239, 177, 240, 174, 76, 18, 145, 207, 45, 115, - 202, 148, 118, 40, 171, 245, 23, 73, 8, 86, 180, 234, 105, 55, 213, 139, - 87, 9, 235, 181, 54, 104, 138, 212, 149, 203, 41, 119, 244, 170, 72, 22, - 233, 183, 85, 11, 136, 214, 52, 106, 43, 117, 151, 201, 74, 20, 246, 168, - 116, 42, 200, 150, 21, 75, 169, 247, 182, 232, 10, 84, 215, 137, 107, 53 - }; - - return table[crc ^ data]; + // https://www.maximintegrated.com/en/app-notes/index.mvp/id/27 + static const uint8_t table[256] = { + 0, 94, 188, 226, 97, 63, 221, 131, 194, 156, 126, 32, 163, 253, 31, 65, + 157, 195, 33, 127, 252, 162, 64, 30, 95, 1, 227, 189, 62, 96, 130, 220, + 35, 125, 159, 193, 66, 28, 254, 160, 225, 191, 93, 3, 128, 222, 60, 98, + 190, 224, 2, 92, 223, 129, 99, 61, 124, 34, 192, 158, 29, 67, 161, 255, + 70, 24, 250, 164, 39, 121, 155, 197, 132, 218, 56, 102, 229, 187, 89, 7, + 219, 133, 103, 57, 186, 228, 6, 88, 25, 71, 165, 251, 120, 38, 196, 154, + 101, 59, 217, 135, 4, 90, 184, 230, 167, 249, 27, 69, 198, 152, 122, 36, + 248, 166, 68, 26, 153, 199, 37, 123, 58, 100, 134, 216, 91, 5, 231, 185, + 140, 210, 48, 110, 237, 179, 81, 15, 78, 16, 242, 172, 47, 113, 147, 205, + 17, 79, 173, 243, 112, 46, 204, 146, 211, 141, 111, 49, 178, 236, 14, 80, + 175, 241, 19, 77, 206, 144, 114, 44, 109, 51, 209, 143, 12, 82, 176, 238, + 50, 108, 142, 208, 83, 13, 239, 177, 240, 174, 76, 18, 145, 207, 45, 115, + 202, 148, 118, 40, 171, 245, 23, 73, 8, 86, 180, 234, 105, 55, 213, 139, + 87, 9, 235, 181, 54, 104, 138, 212, 149, 203, 41, 119, 244, 170, 72, 22, + 233, 183, 85, 11, 136, 214, 52, 106, 43, 117, 151, 201, 74, 20, 246, 168, + 116, 42, 200, 150, 21, 75, 169, 247, 182, 232, 10, 84, 215, 137, 107, 53 + }; + + return table[crc ^ data]; +} + +static bool _search(const OneWireBus * bus, OneWireBus_SearchState * state) +{ + // Based on https://www.maximintegrated.com/en/app-notes/index.mvp/id/187 + + // initialize for search + int id_bit_number = 1; + int last_zero = 0; + int rom_byte_number = 0; + int id_bit = 0; + int cmp_id_bit = 0; + uint8_t rom_byte_mask = 1; + uint8_t search_direction = 0; + bool search_result = false; + uint8_t crc8 = 0; + + if (_is_init(bus)) + { + // if the last call was not the last one + if (!state->last_device_flag) + { + // 1-Wire reset + if (!_reset(bus)) + { + // reset the search + state->last_discrepancy = 0; + state->last_device_flag = false; + state->last_family_discrepancy = 0; + return false; + } + + // issue the search command + _write_byte(bus, OWB_ROM_SEARCH); + + // loop to do the search + do + { + // read a bit and its complement + id_bit = _read_bit(bus); + cmp_id_bit = _read_bit(bus); + + // check for no devices on 1-wire + if ((id_bit == 1) && (cmp_id_bit == 1)) + break; + else + { + // all devices coupled have 0 or 1 + if (id_bit != cmp_id_bit) + search_direction = id_bit; // bit write value for search + else + { + // if this discrepancy if before the Last Discrepancy + // on a previous next then pick the same as last time + if (id_bit_number < state->last_discrepancy) + search_direction = ((state->rom_code[rom_byte_number] & rom_byte_mask) > 0); + else + // if equal to last pick 1, if not then pick 0 + search_direction = (id_bit_number == state->last_discrepancy); + + // if 0 was picked then record its position in LastZero + if (search_direction == 0) + { + last_zero = id_bit_number; + + // check for Last discrepancy in family + if (last_zero < 9) + state->last_family_discrepancy = last_zero; + } + } + + // set or clear the bit in the ROM byte rom_byte_number + // with mask rom_byte_mask + if (search_direction == 1) + state->rom_code[rom_byte_number] |= rom_byte_mask; + else + state->rom_code[rom_byte_number] &= ~rom_byte_mask; + + // serial number search direction write bit + _write_bit(bus, search_direction); + + // increment the byte counter id_bit_number + // and shift the mask rom_byte_mask + id_bit_number++; + rom_byte_mask <<= 1; + + // if the mask is 0 then go to new SerialNum byte rom_byte_number and reset mask + if (rom_byte_mask == 0) + { + crc8 = _calc_crc(crc8, state->rom_code[rom_byte_number]); // accumulate the CRC + rom_byte_number++; + rom_byte_mask = 1; + } + } + } + while(rom_byte_number < 8); // loop until through all ROM bytes 0-7 + + // if the search was successful then + if (!((id_bit_number < 65) || (crc8 != 0))) + { + // search successful so set LastDiscrepancy,LastDeviceFlag,search_result + state->last_discrepancy = last_zero; + + // check for last device + if (state->last_discrepancy == 0) + state->last_device_flag = true; + + search_result = true; + } + } + + // if no device found then reset counters so next 'search' will be like a first + if (!search_result || !state->rom_code[0]) + { + state->last_discrepancy = 0; + state->last_device_flag = false; + state->last_family_discrepancy = 0; + search_result = false; + } + } + return search_result; } @@ -250,145 +361,176 @@ static uint8_t _calc_crc(uint8_t crc, uint8_t data) OneWireBus * owb_malloc() { - OneWireBus * bus = malloc(sizeof(*bus)); - if (bus != NULL) - { - memset(bus, 0, sizeof(*bus)); - ESP_LOGD(TAG, "malloc %p", bus); - } - else - { - ESP_LOGE(TAG, "malloc failed"); - } - return bus; + OneWireBus * bus = malloc(sizeof(*bus)); + if (bus != NULL) + { + memset(bus, 0, sizeof(*bus)); + ESP_LOGD(TAG, "malloc %p", bus); + } + else + { + ESP_LOGE(TAG, "malloc failed"); + } + return bus; } void owb_free(OneWireBus ** bus) { - if (bus != NULL && (*bus != NULL)) - { - ESP_LOGD(TAG, "free %p", *bus); - free(*bus); - *bus = NULL; - } + if (bus != NULL && (*bus != NULL)) + { + ESP_LOGD(TAG, "free %p", *bus); + free(*bus); + *bus = NULL; + } } void owb_init(OneWireBus * bus, int gpio) { - if (bus != NULL) - { - bus->gpio = gpio; - bus->timing = &_StandardTiming; - bus->init = true; - - // platform specific: - gpio_pad_select_gpio(bus->gpio); - } - else - { - ESP_LOGE(TAG, "bus is NULL"); - } + if (bus != NULL) + { + bus->gpio = gpio; + bus->timing = &_StandardTiming; + bus->init = true; + + // platform specific: + gpio_pad_select_gpio(bus->gpio); + } + else + { + ESP_LOGE(TAG, "bus is NULL"); + } } void owb_use_crc(OneWireBus * bus, bool use_crc) { - if (_is_init(bus)) - { - bus->use_crc = use_crc; - ESP_LOGD(TAG, "use_crc %d", bus->use_crc); - } + if (_is_init(bus)) + { + bus->use_crc = use_crc; + ESP_LOGD(TAG, "use_crc %d", bus->use_crc); + } } int owb_rom_search(OneWireBus * bus) { - // TODO - return 0; + // TODO + return 0; } uint64_t owb_read_rom(const OneWireBus * bus) { - uint64_t rom_code = 0; - if (_is_init(bus)) - { - if (_reset(bus)) - { - uint8_t buffer[8] = { 0 }; - _write_byte(bus, OWB_ROM_READ); - _read_block(bus, buffer, 8); - - // device provides LSB first - for (int i = 7; i >= 0; --i) - { - // watch out for integer promotion - rom_code |= ((uint64_t)buffer[i] << (8 * i)); - } - - if (bus->use_crc) - { - // check CRC - uint8_t crc = 0; - for (int i = 0; i < 8; ++i) - { - crc = _calc_crc(crc, buffer[i]); - } - ESP_LOGD(TAG, "crc 0x%02x", crc); - - if (crc != 0) - { - ESP_LOGE(TAG, "CRC failed"); - rom_code = 0; - } - - ESP_LOGD(TAG, "rom_code 0x%08" PRIx64, rom_code); - } - } - else - { - ESP_LOGE(TAG, "ds18b20 device not responding"); - } - } - return rom_code; + uint64_t rom_code = 0; + if (_is_init(bus)) + { + if (_reset(bus)) + { + uint8_t buffer[8] = { 0 }; + _write_byte(bus, OWB_ROM_READ); + _read_block(bus, buffer, 8); + + // device provides LSB first + for (int i = 7; i >= 0; --i) + { + // watch out for integer promotion + rom_code |= ((uint64_t)buffer[i] << (8 * i)); + } + + if (bus->use_crc) + { + // check CRC + uint8_t crc = 0; + for (int i = 0; i < 8; ++i) + { + crc = _calc_crc(crc, buffer[i]); + } + ESP_LOGD(TAG, "crc 0x%02x", crc); + + if (crc != 0) + { + ESP_LOGE(TAG, "CRC failed"); + rom_code = 0; + } + + ESP_LOGD(TAG, "rom_code 0x%08" PRIx64, rom_code); + } + } + else + { + ESP_LOGE(TAG, "ds18b20 device not responding"); + } + } + return rom_code; } bool owb_reset(const OneWireBus * bus) { - return _reset(bus); + return _reset(bus); } void owb_write_byte(const OneWireBus * bus, uint8_t data) { - _write_byte(bus, data); + _write_byte(bus, data); } uint8_t owb_read_byte(const OneWireBus * bus) { - return _read_byte(bus); + return _read_byte(bus); } uint8_t * owb_read_bytes(const OneWireBus * bus, uint8_t * buffer, unsigned int len) { - return _read_block(bus, buffer, len); + return _read_block(bus, buffer, len); } const uint8_t * owb_write_bytes(const OneWireBus * bus, const uint8_t * buffer, unsigned int len) { - return _write_block(bus, buffer, len); + return _write_block(bus, buffer, len); } void owb_write_rom_code(const OneWireBus * bus, uint64_t rom_code) { - uint8_t buffer[sizeof(uint64_t)] = {0}; - for (int i = 0; i < sizeof(buffer); ++i) - { - // LSB first - buffer[i] = rom_code & 0xFF; - rom_code >>= 8; - } - _write_block(bus, buffer, sizeof(buffer)); + uint8_t buffer[sizeof(uint64_t)] = {0}; + for (int i = 0; i < sizeof(buffer); ++i) + { + // LSB first + buffer[i] = rom_code & 0xFF; + rom_code >>= 8; + } + _write_block(bus, buffer, sizeof(buffer)); } uint8_t owb_crc8(uint8_t crc, uint8_t data) { - return _calc_crc(crc, data); + return _calc_crc(crc, data); } +bool owb_search_first(const OneWireBus * bus, OneWireBus_SearchState * state) +{ + bool result = false; + if (state != NULL) + { + memset(state->rom_code, 0, sizeof(state->rom_code)); + state->last_discrepancy = 0; + state->last_family_discrepancy = 0; + state->last_device_flag = false; + result = _search(bus, state); + } + else + { + ESP_LOGE(TAG, "state is NULL"); + } + return result; +} + +bool owb_search_next(const OneWireBus * bus, OneWireBus_SearchState * state) +{ + bool result = false; + if (state != NULL) + { + result = _search(bus, state); + } + else + { + ESP_LOGE(TAG, "state is NULL"); + } + return result; +} diff --git a/main/owb.h b/main/owb.h index f28693a..927e401 100644 --- a/main/owb.h +++ b/main/owb.h @@ -2,6 +2,7 @@ #define ONE_WIRE_BUS_H #include +#include #ifdef __cplusplus extern "C" { @@ -54,6 +55,9 @@ void owb_use_crc(OneWireBus * bus, bool use_crc); */ uint64_t owb_read_rom(const OneWireBus * bus); +// TODO +bool owb_verify_rom(const OneWireBus * bus, uint64_t rom_code); + /** * @brief Reset the 1-Wire bus. * @param[in] bus Pointer to initialised bus instance. @@ -100,13 +104,28 @@ const uint8_t * owb_write_bytes(const OneWireBus * bus, const uint8_t * buffer, */ void owb_write_rom_code(const OneWireBus * bus, uint64_t rom_code); - /** +/** * @brief 1-Wire 8-bit CRC lookup. * @param[in] crc Starting CRC value. Pass in prior CRC to accumulate. * @param[in] data Byte to feed into CRC. * @return Resultant CRC value. */ - uint8_t owb_crc8(uint8_t crc, uint8_t data); +uint8_t owb_crc8(uint8_t crc, uint8_t data); + + +// Search API +struct OneWireBus_SearchState +{ + uint8_t rom_code[8]; + int last_discrepancy; + int last_family_discrepancy; + int last_device_flag; +}; +typedef struct OneWireBus_SearchState OneWireBus_SearchState; + +bool owb_search_first(const OneWireBus * bus, OneWireBus_SearchState * state); +bool owb_search_next(const OneWireBus * bus, OneWireBus_SearchState * state); + #ifdef __cplusplus diff --git a/main/owb_static.h b/main/owb_static.h index 17a8b2e..7d8fd67 100644 --- a/main/owb_static.h +++ b/main/owb_static.h @@ -13,10 +13,10 @@ extern "C" { struct _OneWireBus { - bool init; - int gpio; - const struct _OneWireBus_Timing * timing; - bool use_crc; + bool init; + int gpio; + const struct _OneWireBus_Timing * timing; + bool use_crc; }; typedef struct _OneWireBus OneWireBus_Static;