Revision 0:d95f6ac4c8d6, committed 2015-03-07

Comitter:

kenjiArai

Date:

Sat Mar 07 23:44:42 2015 +0000

Child:

1:4a02a8fbf021

Commit message:

Digital 16bit Serial Output Type Ambient Light Sensor IC by ROHM, Ambient light sensor (Illuminance to digital converter)

Changed in this revision

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/BH1750.cpp	Sat Mar 07 23:44:42 2015 +0000
@@ -0,0 +1,99 @@
+/*
+ * mbed library program
+ *  light intensity sensor module with built-in a 16 bit AD converter generating digital signal.
+ *  BH1750 by ROHM Co.,Ltd.
+ *
+ * Copyright (c) 2015 Kenji Arai / JH1PJL
+ *  http://www.page.sannet.ne.jp/kenjia/index.html
+ *  http://mbed.org/users/kenjiArai/
+ *      Created: March      7th, 2015
+ *      Revised: March      8th, 2015
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
+ * INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE
+ * AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
+ * DAMAGES OR OTHER  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+#include "BH1750.h"
+
+BH1750::BH1750 (PinName p_sda, PinName p_scl) : _i2c(p_sda, p_scl)
+{
+    BH1750_addr = BH1750_G_CHIP_ADDR;
+    init();
+}
+
+BH1750::BH1750 (PinName p_sda, PinName p_scl, uint8_t addr) : _i2c(p_sda, p_scl)
+{
+    BH1750_addr = addr;
+    init();
+}
+
+BH1750::BH1750 (I2C& p_i2c) : _i2c(p_i2c)
+{
+    BH1750_addr = BH1750_G_CHIP_ADDR;
+    init();
+}
+
+BH1750::BH1750 (I2C& p_i2c, uint8_t addr) : _i2c(p_i2c)
+{
+    BH1750_addr = addr;
+    init();
+}
+
+/////////////// Read Lux from sensor //////////////////////
+float BH1750::lux()
+{
+    float lux;
+
+    _i2c.read(BH1750_addr, (char *)dt, 2, false);
+    lux = (float)(dt[0] << 8 | dt[1]);
+    lux = lux / 1.2 * ((float)sensitivity/69);
+    return lux;
+}
+
+/////////////// Initialize ////////////////////////////////
+void BH1750::init()
+{
+    _i2c.frequency(100000);
+    power_up();
+    sensitivity = SENS_1R00;
+    set_sensitivity(sensitivity);
+}
+
+/////////////// Timing Register ///////////////////////////
+void BH1750::set_sensitivity(uint8_t parameter)
+{
+    if (parameter > SENS_3R68){
+        parameter = SENS_3R68;
+    } else if (parameter < SENS_0R45){
+        parameter = SENS_0R45;
+    }
+    dt[0] = CMD_M_TIME_H | (parameter >> 5);    // Set High byte
+    _i2c.write((int)BH1750_addr, (char *)dt, 1, false);
+    dt[0] = CMD_M_TIME_L | (parameter & 0x1f);  // Set Low byte
+    _i2c.write((int)BH1750_addr, (char *)dt, 1, false);
+    dt[0] = CMD_C_H_RES_M;      // Measurement mode: High Resolution
+    _i2c.write((int)BH1750_addr, (char *)dt, 1, false);
+    wait_ms(240);   // need normal conversion time(120mS) x 2
+}
+
+/////////////// Power ON/OFF //////////////////////////////
+void BH1750::power_up()
+{
+    dt[0] = CMD_PWR_UP;
+    _i2c.write((int)BH1750_addr, (char *)dt, 1, false);
+}
+
+void BH1750::power_down()
+{
+    dt[0] = CMD_PWR_DWN;
+    _i2c.write((int)BH1750_addr, (char *)dt, 1, false);
+}
+
+/////////////// I2C Freq. /////////////////////////////////
+void BH1750::frequency(int hz)
+{
+    _i2c.frequency(hz);
+}

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/BH1750.h	Sat Mar 07 23:44:42 2015 +0000
@@ -0,0 +1,128 @@
+/*
+ * mbed library program
+ *  light intensity sensor module with built-in a 16 bit AD converter generating digital signal.
+ *  BH1750 by ROHM Co.,Ltd.
+ *
+ * Copyright (c) 2015 Kenji Arai / JH1PJL
+ *  http://www.page.sannet.ne.jp/kenjia/index.html
+ *  http://mbed.org/users/kenjiArai/
+ *      Created: March      7th, 2015
+ *      Revised: March      8th, 2015
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
+ * INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE
+ * AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
+ * DAMAGES OR OTHER  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+/*
+ *---------------- REFERENCE ----------------------------------------------------------------------
+ * Original Information
+ *  http://www.rohm.co.jp/web/japan/products/-/product/BH1750FVI
+ * Device kit
+ *  http://www.aitendo.com/product/10240
+ */
+
+#ifndef BH1750_H
+#define BH1750_H
+
+#include "mbed.h"
+
+// light intensity sensor, BH1750
+// 7bit address = 0b0100011(0x23) or 0b1011100(0x5c)
+#define BH1750_G_CHIP_ADDR         (0x23 << 1)
+#define BH1750_V_CHIP_ADDR         (0x5c << 1)
+
+////////////// COMMAND ////////////////////////////////////
+#define CMD_PWR_DWN                0x00
+#define CMD_PWR_UP                 0x01
+#define CMD_RESET                  0x07
+#define CMD_C_H_RES_M              0x10
+#define CMD_C_H_RES_M2             0x11
+#define CMD_C_L_RES_M              0x13
+#define CMD_1_H_RES_M              0x20
+#define CMD_1_H_RES_M2             0x21
+#define CMD_1_L_RES_M              0x23
+#define CMD_M_TIME_H               0x40
+#define CMD_M_TIME_L               0x60
+
+////////////// SENSITIVITY ////////////////////////////////
+#define SENS_1R00                  69
+#define SENS_3R68                  254
+#define SENS_0R45                  31
+#define SENS_2R00                  138
+#define SENS_0R50                  35
+
+/** Interface for Luminosity sensor, BH1750
+ * @code
+ * #include "mbed.h"
+ * #include "BH1750.h"
+ *
+ * // I2C Communication
+ *  BH1750      lum(dp5,dp27);    // BH1750 SDA, SCL
+ * // If you connected I2C line not only this device but also other devices,
+ * //     you need to declare following method.
+ *  I2C         i2c(dp5,dp27);    // SDA, SCL
+ *  BH1750      lum(i2c);         // BH1750 SDA, SCL (Data available every 120mSec)
+ *
+ * int main() {;
+ *   while(true){
+ *      printf("Illuminance: %+7.2f [Lux]\r\n", lum.lux());
+ *      wait(1.0);
+ *   }
+ * }
+ * @endcode
+ */
+
+class BH1750
+{
+public:
+    /** Configure data pin
+      * @param data SDA and SCL pins
+      */
+    BH1750(PinName p_sda, PinName p_scl);
+    BH1750(PinName p_sda, PinName p_scl, uint8_t addr);
+
+    /** Configure data pin (with other devices on I2C line)
+      * @param I2C previous definition
+      */
+    BH1750(I2C& p_i2c);
+    BH1750(I2C& p_i2c, uint8_t addr);
+
+    /** Get Illuminance, unit of Lux
+      * @param none
+      * @return Lux
+      */
+    float lux(void);
+
+    /** Set sensor sensitivity adjustment
+      * @param sensitivity parameter
+      * @return none
+      */
+    void set_sensitivity(uint8_t parameter);
+
+    /** Set I2C clock frequency
+      * @param freq.
+      * @return none
+      */
+    void frequency(int hz);
+
+    /** Power Up/Down
+      * @param none
+      * @return none
+      */
+    void power_up(void);
+    void power_down(void);
+
+protected:
+    I2C  _i2c;
+
+    void init(void);
+
+private:
+    uint8_t  BH1750_addr;
+    uint8_t  dt[4];
+    int8_t   sensitivity;
+};
+
+#endif      // BH1750_H