Update readme

Author: aeraterta

README.md

@@ -1 +1,135 @@
-# lsm303
+# LSM303DLHC Support Library in C
+
+This project is designed to interface the [LSM303DLHC](https://www.st.com/resource/en/datasheet/lsm303dlhc.pdf) using C language.
+
+## Usage
+
+### Shims
+First update I2C shim functions to let this library communicate with your system:
+
+>**Note**: These shims are initially design to work in Zephyr RTOS using the build flag PLATFORM_ZEPHYR.
+
+For I2C Write: 
+
+```
+/**
+ * @brief Writes data to a register of the LSM303 device over I2C.
+ *
+ * This function writes data to a specified register of the LSM303 device
+ * using the provided data buffer.
+ *
+ * @param device      Pointer to the LSM303 device structure.
+ * @param address     I2C address of the LSM303 device.
+ * @param data_buffer Pointer to the buffer containing the data to be written.
+ *
+ * @return
+ *   - 0 on success.
+ *   - Non-zero error code on failure.
+ */
+int8_t lsm303_i2c_write(lsm303_dev *device, uint8_t address,
+                        uint8_t *data_buffer) {
+#ifdef PLATFORM_ZEPHYR
+  uint32_t bytecount = 2;
+  return i2c_write(device->i2c0_dev, data_buffer, bytecount, address);
+#endif
+}
+```
+
+FOr I2C Read:
+
+```
+/**
+ * @brief Reads a register value from the LSM303 device via I2C.
+ *
+ * Reads a single register from the LSM303 device and stores the retrieved value
+ * in the specified buffer.
+ *
+ * @param device      Pointer to the LSM303 device structure.
+ * @param address     I2C address of the LSM303 device.
+ * @param reg         Register address to read from.
+ * @param read_data   Pointer to the buffer where the read value will be stored.
+ *
+ * @return
+ *   - 0 on success.
+ *   - Non-zero error code on failure.
+ */
+int8_t lsm303_i2c_read(lsm303_dev *device, uint8_t address, uint8_t reg,
+                       uint8_t *read_data) {
+#ifdef PLATFORM_ZEPHYR
+  uint32_t bytecount = 1;
+
+  if (i2c_write(device->i2c0_dev, &reg, bytecount, address) !=
+      LSM303_STATUS_SUCCESS) {
+    return LSM303_STATUS_API_ERR;
+  }
+
+  if (i2c_read(device->i2c0_dev, read_data, sizeof(*read_data), address) != 0) {
+    return LSM303_STATUS_API_ERR;
+  }
+
+  return LSM303_STATUS_SUCCESS;
+#endif
+```
+
+### Application
+
+You may refer to [mcu-dev/dev-apps](https://github.com/mcu-dev/dev-apps) repository written for Zephyr RTOS for a sample application.
+
+```
+static lsm303_dev dev;
+static lsm303_init_param dev_param;
+static lsm303_axes_data lsm303_acc_data;
+uint8_t addr = 0x00;
+
+int main(void){
+    dev_param.acc_power_mode = ACC_NORMAL;
+    dev_param.acc_odr = ACC_ODR_1HZ;
+    dev_param.acc_scale = ACC_SCALE_8G;
+    dev_param.acc_resolution = ACC_RESOLUTION_LOW;
+    dev_param.acc_axes_config.acc_axes = ACC_AXES_ENABLE_XYZ;
+
+    if (lsm303_setup(&dev, dev_param) == LSM303_STATUS_SUCCESS) {
+        /* Successful */
+    } else {
+        /* Error occur */
+    }
+
+    while(1){
+        if (lsm303_data_ready(&dev) == LSM303_STATUS_SUCCESS) {
+            if (dev.acc_axes_config.enable.x) {
+                if (dev.acc_axes_config.ready.x) {
+                    if (lsm303_get_x_raw_data(&dev, &lsm303_acc_data) ==
+                        LSM303_STATUS_SUCCESS) {
+                        /* Get raw value or get G equivalent */
+                    }
+                }
+            }
+
+            if (dev.acc_axes_config.enable.y) {
+                if (dev.acc_axes_config.ready.y) {
+                    if (lsm303_get_y_raw_data(&dev, &lsm303_acc_data) ==
+                        LSM303_STATUS_SUCCESS) {
+                        /* Get raw value or get G equivalent */
+                    }
+                }
+            }
+
+            if (dev.acc_axes_config.enable.z) {
+                if (dev.acc_axes_config.ready.z) {
+                    if (lsm303_get_z_raw_data(&dev, &lsm303_acc_data) ==
+                        LSM303_STATUS_SUCCESS) {
+                        /* Get raw value or get G equivalent */
+                    }
+                }
+            }
+        }
+        /* Delay to handle polling */
+    }
+    return 0;
+}
+
+```
+
+## License
+
+Licensed under the MIT license.