MEMS pressure sensor by STMicroelectronics. FIFO Hardware digital filter as default.

Fork of LPS25H by Kenji Arai

Revision:
0:8fc511bd51af
Child:
1:9db35e42ddbc
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/LPS25H.cpp	Sun Feb 22 00:59:52 2015 +0000
@@ -0,0 +1,156 @@
+/*
+ * mbed library program
+ *  LPS25H MEMS pressure sensor: 260-1260 hPa absolute digital output barometer
+ *   made by STMicroelectronics
+ *   http://www.st-japan.co.jp/web/catalog/sense_power/FM89/SC1316/PF255230?s_searchtype=partnumber
+ *
+ * Copyright (c) 2015 Kenji Arai / JH1PJL
+ *  http://www.page.sannet.ne.jp/kenjia/index.html
+ *  http://mbed.org/users/kenjiArai/
+ *      Created: Feburary  21st, 2015
+ *      Revised: Feburary  22nd, 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 "LPS25H.h"
+
+LPS25H::LPS25H (PinName p_sda, PinName p_scl, uint8_t addr) : _i2c(p_sda, p_scl)
+{
+    LPS25H_addr = addr;
+    LPS25H_mode = FIFO_HW_FILTER;
+    init();
+}
+
+LPS25H::LPS25H (PinName p_sda, PinName p_scl, uint8_t addr, uint8_t mode) : _i2c(p_sda, p_scl)
+{
+    LPS25H_addr = addr;
+    LPS25H_mode = mode;
+    init();
+}
+
+LPS25H::LPS25H (I2C& p_i2c, uint8_t addr) : _i2c(p_i2c)
+{
+    LPS25H_addr = addr;
+    LPS25H_mode = FIFO_HW_FILTER;
+    init();
+}
+
+LPS25H::LPS25H (I2C& p_i2c, uint8_t addr, uint8_t mode) : _i2c(p_i2c)
+{
+    LPS25H_addr = addr;
+    LPS25H_mode = mode;
+    init();
+}
+
+/////////////// Initialize ////////////////////////////////
+void LPS25H::init(void)
+{
+    _i2c.frequency(100000);
+    // Check acc is available of not
+    dt[0] = LPS25H_WHO_AM_I;
+    _i2c.write(LPS25H_addr, dt, 1, true);
+    _i2c.read(LPS25H_addr, dt, 1, false);
+    if (dt[0] == I_AM_LPS25H) {
+        LPS25H_id = I_AM_LPS25H;
+        LPS25H_ready = 1;
+    } else {
+        LPS25H_id = 0;
+        LPS25H_ready = 0;
+        return;     // acc chip is NOT on I2C line then terminate
+    }
+    if (LPS25H_mode == FIFO_HW_FILTER){
+        // Hardware digital filter
+        // AN4450 April 2014 Rev1 P20/26, Filter enabling and suggested configuration
+        dt[0] = LPS25H_RES_CONF;
+        dt[1] = 0x05;
+        _i2c.write(LPS25H_addr, dt, 2, false);
+        dt[0] = LPS25H_FIFO_CTRL;
+        dt[1] = 0xdf;
+        _i2c.write(LPS25H_addr, dt, 2, false);
+        dt[0] = LPS25H_CTRL_REG2;
+        dt[1] = 0x40;
+        _i2c.write(LPS25H_addr, dt, 2, false);
+        dt[0] = LPS25H_CTRL_REG1;
+        dt[1] = 0x90;
+        _i2c.write(LPS25H_addr, dt, 2, false);
+    } else {
+        dt[0] = LPS25H_CTRL_REG2;
+        dt[1] = 0x0;
+        _i2c.write(LPS25H_addr, dt, 2, false);       
+        dt[0] = LPS25H_CTRL_REG1;
+        dt[1] = CR_STD_SET;
+        _i2c.write(LPS25H_addr, dt, 2, false);
+    }
+}
+
+/////////////// Start conv. and gwt all data //////////////
+void LPS25H::get(void)
+{
+    if (LPS25H_ready == 0) {
+        press = 0;
+        temp = 0;
+        return;
+    }
+    dt[0] = LPS25H_PRESS_POUT_XL | 0x80;
+    _i2c.write(LPS25H_addr, dt, 1, true);
+    _i2c.read(LPS25H_addr, dt, 3, false);
+    press = dt[2] << 16 | dt[1] << 8 | dt[0];
+    dt[0] = LPS25H_TEMP_OUT_L | 0x80;
+    _i2c.write(LPS25H_addr, dt, 1, true);
+    _i2c.read(LPS25H_addr, dt, 2, false);
+    temp = dt[1] << 8 | dt[0];
+}
+
+/////////////// Read data from sensor /////////////////////
+float LPS25H::pressure()
+{
+    return (float)press / 4096;
+}
+
+/////////////// Read data from sensor /////////////////////
+float LPS25H::temperature()
+{
+    return (float)temp / 480  + 42.5;
+}
+
+/////////////// ID ////////////////////////////////////////
+uint8_t LPS25H::read_id()
+{
+    dt[0] = LPS25H_WHO_AM_I;
+    _i2c.write(LPS25H_addr, dt, 1, true);
+    _i2c.read(LPS25H_addr, dt, 1, false);
+    return (uint8_t)dt[0];
+}
+
+/////////////// I2C Freq. /////////////////////////////////
+void LPS25H::frequency(int hz)
+{
+    _i2c.frequency(hz);
+}
+
+/////////////// General purpose R/W ///////////////////////
+uint8_t LPS25H::read_reg(uint8_t addr)
+{
+    if (LPS25H_ready == 1) {
+        dt[0] = addr;
+        _i2c.write(LPS25H_addr, dt, 1, true);
+        _i2c.read(LPS25H_addr, dt, 1, false);
+    } else {
+        dt[0] = 0xff;
+    }
+    return (uint8_t)dt[0];
+}
+
+void LPS25H::write_reg(uint8_t addr, uint8_t data)
+{
+    if (LPS25H_ready == 1) {
+        dt[0] = addr;
+        dt[1] = data;
+        _i2c.write(LPS25H_addr, dt, 2, false);
+    }
+}