initial commit

LICENSE

@@ -0,0 +1,27 @@
+Copyright (c) 2018, Sensirion AG
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are met:
+
+* Redistributions of source code must retain the above copyright notice, this
+  list of conditions and the following disclaimer.
+
+* Redistributions in binary form must reproduce the above copyright notice,
+  this list of conditions and the following disclaimer in the documentation
+  and/or other materials provided with the distribution.
+
+* Neither the name of Sensirion AG nor the names of its
+  contributors may be used to endorse or promote products derived from
+  this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH 

README.md

@@ -0,0 +1,45 @@
+# Arduino library for Sensirion SDP3x and SDP8xx series
+
+This is an unofficial library for Sensirion SDP3x and SDP8xx sensors. Both 500Pa
+and 125Pa sensor types are supported.
+
+## Getting started
+
+To get started, have a look at the `sdp_generic` example from the "Examples" menu.
+Follow the steps below to initialize for your sensor:
+
+### Initializing for SDP3x on I2C address 0x21
+
+I2C address is the default for the SDP3x series. The `sdp_generic` sample
+will do that by default, without requiring any changes.
+
+### Initializing for SDP3x on an I2C address other than 0x21
+
+To use an address other than 0x21, you can pass an argument when setting up
+the sensor. In the example, comment out line 6, and uncomment line 10, like so:
+
+```c++
+// SDP3XSensor sdp;
+
+// If your SDP3x is not using the default I2C address of 0x21, uncomment the
+// line below:
+SDP3XSensor sdp(SDP3X_I2C_ADDR_22);
+```
+Alternatively, you can use `SDP3X_I2C_ADDR_23` instead of `SDP3X_I2C_ADDR_22`
+
+### Initializing for SDP8xx
+
+To use it with an SDP8xx series sensor, comment out line 6, and uncomment
+line 14, like so:
+
+```c++
+// SDP3XSensor sdp;
+
+// If your SDP3x is not using the default I2C address of 0x21, uncomment the
+// line below:
+// SDP3XSensor sdp(SDP3X_I2C_ADDR_22);
+
+
+// If you're using an SDP8xx, uncomment the line below instead:
+SDP8XXSensor sdp;
+```

examples/sdp_generic/sdp_generic.ino

@@ -0,0 +1,50 @@
+#include <Wire.h>
+
+#include <sdpsensor.h>
+
+// use this for an SDP3x on the default I2C address of 0x21:
+SDP3XSensor sdp;
+
+// If your SDP3x is not using the default I2C address of 0x21, uncomment the
+// line below:
+// SDP3XSensor sdp(SDP3X_I2C_ADDR_22);
+
+
+// If you're using an SDP8xx, uncomment the line below instead:
+// SDP8XXSensor sdp;
+
+
+void setup() {
+  Wire.begin();
+  Serial.begin(9600);
+  delay(1000); // let serial console settle
+
+  int ret = sdp.init();
+  if (!ret) {
+      Serial.print("init(): success\n");
+  } else {
+      Serial.print("init(): failed, ret = ");
+      Serial.println(ret);
+      while (true) {
+        delay(1000);
+      }
+  }
+}
+
+void loop() {
+  int ret = sdp.readSample();
+  if (!ret) {
+      Serial.print("Differential pressure: ");
+      Serial.print(sdp.getDifferentialPressure());
+      Serial.print("Pa | ");
+
+      Serial.print("Temp: ");
+      Serial.print(sdp.getTemperature());
+      Serial.print("C\n");
+  } else {
+      Serial.print("Error in readSample(), ret = ");
+      Serial.println(ret);
+  }
+
+  delay(500);
+}

i2chelper.cpp

@@ -0,0 +1,82 @@
+/*
+ *  Copyright (c) 2015-2018, Sensirion AG <[email protected]>
+ *  All rights reserved.
+ *
+ *  Redistribution and use in source and binary forms, with or without
+ *  modification, are permitted provided that the following conditions are met:
+ *      * Redistributions of source code must retain the above copyright
+ *        notice, this list of conditions and the following disclaimer.
+ *      * Redistributions in binary form must reproduce the above copyright
+ *        notice, this list of conditions and the following disclaimer in the
+ *        documentation and/or other materials provided with the distribution.
+ *      * Neither the name of the Sensirion AG nor the names of its
+ *        contributors may be used to endorse or promote products derived
+ *        from this software without specific prior written permission.
+ *
+ *  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ *  AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ *  IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ *  ARE DISCLAIMED. IN NO EVENT SHALL <COPYRIGHT HOLDER> BE LIABLE FOR ANY
+ *  DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ *  (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ *  LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ *  ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ *  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ *  THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+*/
+
+#include <Arduino.h>
+#include <Wire.h>
+#include "i2chelper.h"
+
+int8_t I2CHelper::i2c_read(uint8_t addr, uint8_t* data, uint16_t count)
+{
+    Wire.requestFrom(addr, count);
+    if (Wire.available() != count) {
+        return -1;
+    }
+    for (int i = 0; i < count; ++i) {
+        data[i] = Wire.read();
+    }
+    return 0;
+}
+
+int8_t I2CHelper::i2c_write(uint8_t addr, const uint8_t* data, uint16_t count, bool appendCrc)
+{
+    Wire.beginTransmission(addr);
+    for (int i = 0; i < count; ++i) {
+        if (Wire.write(data[i]) != 1) {
+            return 1;
+        }
+    }
+    if (appendCrc) {
+      uint8_t crc = crc8(data, count);
+      if (Wire.write(crc) != 1) {
+          return 2;
+      }
+    }
+
+    if (Wire.endTransmission() != 0) {
+        return 3;
+    }
+    return 0;
+}
+
+uint8_t I2CHelper::crc8(const uint8_t* data, uint8_t len)
+{
+  // adapted from SHT21 sample code from http://www.sensirion.com/en/products/humidity-temperature/download-center/
+
+  uint8_t crc = 0xff;
+  uint8_t byteCtr;
+  for (byteCtr = 0; byteCtr < len; ++byteCtr) {
+    crc ^= (data[byteCtr]);
+    for (uint8_t bit = 8; bit > 0; --bit) {
+      if (crc & 0x80) {
+        crc = (crc << 1) ^ 0x31;
+      } else {
+        crc = (crc << 1);
+      }
+    }
+  }
+  return crc;
+}

i2chelper.h

@@ -0,0 +1,40 @@
+/*
+ *  Copyright (c) 2015-2018, Sensirion AG <[email protected]>
+ *  All rights reserved.
+ *
+ *  Redistribution and use in source and binary forms, with or without
+ *  modification, are permitted provided that the following conditions are met:
+ *      * Redistributions of source code must retain the above copyright
+ *        notice, this list of conditions and the following disclaimer.
+ *      * Redistributions in binary form must reproduce the above copyright
+ *        notice, this list of conditions and the following disclaimer in the
+ *        documentation and/or other materials provided with the distribution.
+ *      * Neither the name of the Sensirion AG nor the names of its
+ *        contributors may be used to endorse or promote products derived
+ *        from this software without specific prior written permission.
+ *
+ *  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ *  AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ *  IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ *  ARE DISCLAIMED. IN NO EVENT SHALL <COPYRIGHT HOLDER> BE LIABLE FOR ANY
+ *  DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ *  (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ *  LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ *  ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ *  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ *  THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+*/
+#ifndef __SDP_I2C_HELPER
+#define __SDP_I2C_HELPER
+
+#include <stdint.h>
+
+class I2CHelper
+{
+public:
+    static int8_t i2c_write(uint8_t addr, const uint8_t* data, uint16_t count, bool appendCrc=false);
+    static int8_t i2c_read(uint8_t addr, uint8_t* data, uint16_t count);
+    static uint8_t crc8(const uint8_t* data, uint8_t len);
+};
+
+#endif /* __SCD_I2C_HELPER */

keywords.txt

@@ -0,0 +1,28 @@
+#######################################
+# Syntax Coloring Map For arduino-scd
+#######################################
+
+#######################################
+# Datatypes (KEYWORD1)
+#######################################
+
+SDP3XSensor	KEYWORD1
+SDP8XXSensor	KEYWORD1
+
+#######################################
+# Methods and Functions (KEYWORD2)
+#######################################
+
+init	KEYWORD2
+readSample	KEYWORD2
+getDifferentialPressure		KEYWORD2
+getHumidity	KEYWORD2
+getTemperature	KEYWORD2
+
+#######################################
+# Instances (KEYWORD2)
+#######################################
+
+#######################################
+# Constants (LITERAL1)
+#######################################

library.properties

@@ -0,0 +1,10 @@
+name=arduino-sdp
+version=0.0.1-pre
+author=Johannes Winkelmann
+maintainer=Johannes Winkelmann <[email protected]>
+sentence=Support for Sensirion's Differential Pressure sensors
+paragraph=Supported sensors: SDP3x, SDP8xx
+category=Sensors
+url=https://developer.sensirion.com
+architectures=*
+includes=sdpsensor.h

sdpsensor.cpp

@@ -0,0 +1,99 @@
+/*
+ *  Copyright (c) 2018, Sensirion AG <[email protected]>
+ *  All rights reserved.
+ *
+ *  Redistribution and use in source and binary forms, with or without
+ *  modification, are permitted provided that the following conditions are met:
+ *      * Redistributions of source code must retain the above copyright
+ *        notice, this list of conditions and the following disclaimer.
+ *      * Redistributions in binary form must reproduce the above copyright
+ *        notice, this list of conditions and the following disclaimer in the
+ *        documentation and/or other materials provided with the distribution.
+ *      * Neither the name of the Sensirion AG nor the names of its
+ *        contributors may be used to endorse or promote products derived
+ *        from this software without specific prior written permission.
+ *
+ *  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ *  AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ *  IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ *  ARE DISCLAIMED. IN NO EVENT SHALL <COPYRIGHT HOLDER> BE LIABLE FOR ANY
+ *  DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ *  (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ *  LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ *  ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ *  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ *  THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+*/
+
+#include <Arduino.h>
+
+#include "sdpsensor.h"
+#include "i2chelper.h"
+
+int SDPSensor::init()
+{
+  // try to read product id
+  const uint8_t CMD_LEN = 2;
+  uint8_t cmd0[CMD_LEN] = { 0x36, 0x7C };
+  uint8_t cmd1[CMD_LEN] = { 0xE1, 0x02 };
+
+  const uint8_t DATA_LEN = 18;
+  uint8_t data[DATA_LEN] = { 0 };
+
+  uint8_t ret = I2CHelper::i2c_write(mI2CAddress, cmd0, CMD_LEN);
+  if (ret != 0) {
+    return 1;
+  }
+  ret = I2CHelper::i2c_write(mI2CAddress, cmd1, CMD_LEN);
+  if (ret != 0) {
+    return 2;
+  }
+  ret = I2CHelper::i2c_read(mI2CAddress, data, DATA_LEN);
+  if (ret != 0) {
+    return 3;
+  }
+
+  // at this point, we don't really care about the data just yet, but
+  // we may use that in the future. Either way, the sensor responds, and
+  return 0;
+}
+
+int SDPSensor::readSample()
+{
+  const uint8_t CMD_LEN = 2;
+  uint8_t cmd[CMD_LEN] = { 0x36, 0x2F };
+
+  const uint8_t DATA_LEN = 9;
+  uint8_t data[DATA_LEN] = { 0 };
+
+  if (I2CHelper::i2c_write(mI2CAddress, cmd, CMD_LEN) != 0) {
+    return 1;
+  }
+
+  delay(100); // theoretically 45ms
+
+  if (I2CHelper::i2c_read(mI2CAddress, data, DATA_LEN) != 0) {
+    return 1;
+  }
+
+  // TODO: check CRC
+
+  int16_t dp_raw   = (int16_t)data[0] << 8 | data[1];
+  int16_t temp_raw = (int16_t)data[3] << 8 | data[4];
+  int8_t dp_scale  = (int16_t)data[7] << 8 | data[7];
+
+  mDifferentialPressure = dp_raw / (float)dp_scale;
+  mTemperature = temp_raw / 200.0;
+
+  return 0;
+}
+
+float SDPSensor::getDifferentialPressure() const
+{
+  return mDifferentialPressure;
+}
+
+float SDPSensor::getTemperature() const
+{
+  return mTemperature;
+}