Diff: BH1750.cpp

Revision:

0:d95f6ac4c8d6

Child:

1:4a02a8fbf021

--- /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);
+}