uvis25.cpp

00001 /* Copyright (c) 2009 Nordic Semiconductor. All Rights Reserved.
00002  *
00003  * The information contained herein is property of Nordic Semiconductor ASA.
00004  * Terms and conditions of usage are described in detail in NORDIC
00005  * SEMICONDUCTOR STANDARD SOFTWARE LICENSE AGREEMENT.
00006  *
00007  * Licensees are granted free, non-transferable use of the information. NO
00008  * WARRANTY of ANY KIND is provided. This heading must NOT be removed from
00009  * the file.
00010  *df
00011  */
00012 
00013 #include <stdbool.h>
00014 #include <stdint.h>
00015 
00016 #include <mbed.h>
00017 #include "uvis25.h"
00018 
00019 I2C i2c_uvi(p22, p20);    //SDA, SCL
00020 
00021 static const char uvis25_expected_who_am_i = 0xCAU; //!< Expected value to get from WHO_AM_I register.
00022 
00023 bool uvis25_init(void)
00024 {   
00025   bool transfer_succeeded = true;
00026 
00027   i2c_uvi.frequency(400000);
00028     uvis25_register_write(0x20 , 0x01); 
00029                                 
00030   // Read and verify product ID
00031   transfer_succeeded &= uvis25_verify_product_id();
00032 
00033   return transfer_succeeded;
00034 }
00035 
00036 bool uvis25_verify_product_id(void)
00037 {
00038     char who_am_i[1];
00039     uvis25_register_read(UVIS25_ADDRESS_WHO_AM_I, &who_am_i[0], 1);
00040     if (who_am_i[0] != uvis25_expected_who_am_i) return false;
00041     else return true;
00042 }
00043 
00044 void uvis25_register_write(uint8_t register_address, uint8_t value)
00045 {   
00046     char w2_data[2];
00047     
00048     w2_data[0] = register_address;
00049     w2_data[1] = value;
00050     i2c_uvi.write(UVIS25_WriteADDE, w2_data, 2);      
00051 
00052 }
00053 
00054 void uvis25_register_read(char register_address, char *destination, uint8_t number_of_bytes)
00055 {
00056   i2c_uvi.write(UVIS25_WriteADDE, &register_address, 1, 1);
00057   i2c_uvi.read(UVIS25_WriteADDE, destination, number_of_bytes);  
00058 }
00059                
00060     
00061 uint8_t UVIS25_ReadUVI(void)
00062 {
00063     char UVI_reading;
00064     uvis25_register_read(0x28, &UVI_reading, 1);
00065     return (uint8_t) UVI_reading;
00066 }