mq9:: added new sensor

Signed-off-by: Kiveisha Yevgeniy <yevgeniy.kiveisha@intel.com>

src/gas/gas.cxx

@@ -0,0 +1,105 @@
+/*
+ * Author: Brendan Le Foll <brendan.le.foll@intel.com>
+ * Copyright (c) 2014 Intel Corporation.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * 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 <iostream>
+#include <unistd.h>
+#include <stdlib.h>
+#include <functional>
+#include <string.h>
+#include "gas.h"
+
+using namespace upm;
+
+Gas::Gas(int gasPin) {
+    // initialise analog gas input
+    m_gasCtx = mraa_aio_init(gasPin);
+}
+
+Gas::~Gas() {
+    // close analog input
+    mraa_result_t error;
+    error = mraa_aio_close(m_gasCtx);
+    if (error != MRAA_SUCCESS) {
+        mraa_result_print(error);
+    }
+}
+
+int
+Gas::getSampledWindow (unsigned int freqMS, unsigned int numberOfSamples,
+                            uint16_t * buffer) {
+    int sampleIdx = 0;
+
+    // must have freq
+    if (!freqMS) {
+        return 0;
+    }
+
+    // too much samples
+    if (numberOfSamples > 0xFFFFFF) {
+        return 0;
+    }
+
+    while (sampleIdx < numberOfSamples) {
+        buffer[sampleIdx++] = mraa_aio_read (m_gasCtx);
+        usleep(freqMS * 1000);
+    }
+
+    return sampleIdx;
+}
+
+int
+Gas::findThreshold (thresholdContext* ctx, unsigned int threshold,
+                                uint16_t * buffer, unsigned int len) {
+    long sum = 0;
+    for (unsigned int i = 0; i < len; i++) {
+        sum += buffer[i];
+    }
+
+    ctx->averageReading = sum / len;
+    ctx->runningAverage = (((ctx->averagedOver-1) * ctx->runningAverage) + ctx->averageReading) / ctx->averagedOver;
+
+    if (ctx->runningAverage > threshold) {
+        return ctx->runningAverage;
+    } else {
+        return 0;
+    }
+}
+
+int
+Gas::getSampledData (thresholdContext* ctx) {
+    return ctx->runningAverage;
+}
+
+int
+Gas::getSample (thresholdContext* ctx) {
+    return mraa_aio_read (m_gasCtx);
+}
+
+void
+Gas::printGraph (thresholdContext* ctx, uint8_t resolution) {
+    std::cout << "(" << ctx->runningAverage << ") | ";
+    for (int i = 0; i < ctx->runningAverage / resolution; i++)
+        std::cout << "*";
+    std::cout << std::endl;
+}