Merge pull request #510 from JellevanKraaij/master

feat(ds18b20): Add single device mode (no enumeration 1-Wire bus) (BSP-637)

Author: suda-morris

components/ds18b20/CHANGELOG.md

@@ -1,3 +1,7 @@
+## 0.1.2
+
+- Add single device function (ds18b20_new_single_device) to create a new DS18B20 device instance without enumerating all devices on the bus.
+
 ## 0.1.1
 
 - Fix the issue that sign-bit is not extended properly when doing temperature value conversion.

components/ds18b20/idf_component.yml

@@ -1,4 +1,4 @@
-version: "0.1.1"
+version: "0.1.2"
 description: DS18B20 device driver
 url: https://github.com/espressif/esp-bsp/tree/master/components/ds18b20
 dependencies:

components/ds18b20/include/ds18b20.h

@@ -42,6 +42,21 @@ typedef struct {
  */
 esp_err_t ds18b20_new_device(onewire_device_t *device, const ds18b20_config_t *config, ds18b20_device_handle_t *ret_ds18b20);
 
+/**
+ * @brief Create a new singe device bus DS18B20 device based on a 1-Wire bus (not enumerated)
+ *        this function assumes that the device is a DS18B20 device and there is only one device on the bus
+ *
+ * @param[in] bus 1-Wire bus handle
+ * @param[in] config DS18B20 configuration
+ * @param[out] ret_ds18b20 Returned DS18B20 device handle
+ * @return esp_err_t
+ *      - ESP_OK: Create DS18B20 device successfully
+ *      - ESP_ERR_INVALID_ARG: Create DS18B20 device failed due to invalid argument
+ *      - ESP_ERR_NO_MEM: Create DS18B20 device failed due to out of memory
+ *      - ESP_FAIL: Create DS18B20 device failed due to other reasons
+ */
+esp_err_t ds18b20_new_single_device(onewire_bus_handle_t bus, const ds18b20_config_t *config, ds18b20_device_handle_t *ret_ds18b20);
+
 /**
  * @brief Delete DS18B20 device
  *

components/ds18b20/src/ds18b20.c

@@ -35,6 +35,7 @@ typedef struct  {
 
 typedef struct ds18b20_device_t {
     onewire_bus_handle_t bus;
+    bool single_mode;
     onewire_device_address_t addr;
     uint8_t th_user1;
     uint8_t tl_user2;
@@ -61,6 +62,22 @@ esp_err_t ds18b20_new_device(onewire_device_t *device, const ds18b20_config_t *c
     return ESP_OK;
 }
 
+esp_err_t ds18b20_new_single_device(onewire_bus_handle_t bus, const ds18b20_config_t *config, ds18b20_device_handle_t *ret_ds18b20)
+{
+    ds18b20_device_t *ds18b20 = NULL;
+    ESP_RETURN_ON_FALSE(bus && config && ret_ds18b20, ESP_ERR_INVALID_ARG, TAG, "invalid argument");
+
+    ds18b20 = calloc(1, sizeof(ds18b20_device_t));
+    ESP_RETURN_ON_FALSE(ds18b20, ESP_ERR_NO_MEM, TAG, "no mem for ds18b20");
+    ds18b20->bus = bus;
+    ds18b20->addr = 0;
+    ds18b20->single_mode = true;
+    ds18b20->resolution = DS18B20_RESOLUTION_12B; // DS18B20 default resolution is 12 bits
+
+    *ret_ds18b20 = ds18b20;
+    return ESP_OK;
+}
+
 esp_err_t ds18b20_del_device(ds18b20_device_handle_t ds18b20)
 {
     ESP_RETURN_ON_FALSE(ds18b20, ESP_ERR_INVALID_ARG, TAG, "invalid argument");
@@ -70,6 +87,11 @@ esp_err_t ds18b20_del_device(ds18b20_device_handle_t ds18b20)
 
 static esp_err_t ds18b20_send_command(ds18b20_device_handle_t ds18b20, uint8_t cmd)
 {
+    // No addres mode (singe device connectd to the bus) created using ds18b20_new_single_device
+    if (ds18b20->single_mode) {
+        uint8_t tx_buffer[2] = {ONEWIRE_CMD_SKIP_ROM, cmd};
+        return onewire_bus_write_bytes(ds18b20->bus, tx_buffer, sizeof(tx_buffer));
+    }
     // send command
     uint8_t tx_buffer[10] = {0};
     tx_buffer[0] = ONEWIRE_CMD_MATCH_ROM;