Barometric Pressure Sensor Using MS5637

[Myles L]

Ok, so close! Adding back the rest I get and endless string of � in the serial monitor and nothing adds to Vera.

I don't actually need the temp (tried commenting it out but could not get it to compile) if that makes it easier?

Here is what I have:

#include <SPI.h>
#include <MySensor.h>
#include <Wire.h>
#include <BaroSensor.h>

#define BARO_CHILD 0
#define TEMP_CHILD 1
#define DEVICE_ID 99

unsigned long SLEEP_TIME = 60000; // Sleep time between reads (in seconds)

MySensor gw;

float lastPressure = -1;
float lastTemp = -1;
int lastForecast = -1;
const char *weather[] = {"stable","sunny","cloudy","unstable","thunderstorm","unknown"};
int minutes;
float pressureSamples[180];
int minuteCount = 0;
bool firstRound = true;
float pressureAvg[7];
float dP_dt;
boolean metric;
MyMessage tempMsg(TEMP_CHILD, V_TEMP);
MyMessage pressureMsg(BARO_CHILD, V_PRESSURE);
MyMessage forecastMsg(BARO_CHILD, V_FORECAST);

void setup()
{
Serial.begin(9600);
gw.begin(NULL, DEVICE_ID, false);
delay(1000);
Serial.println("Got to GW.Begin");
// Send the sketch version information to the gateway and Controller
gw.sendSketchInfo("Pressure Sensor", "1.0");
Serial.println("Sketch data Presented");
delay(1000);
BaroSensor.begin();
Serial.println("Brometer Sensor started...");
delay(1000);
// Register sensors to gw (they will be created as child devices)
gw.present(BARO_CHILD, S_BARO);
Serial.println("presenting Barometer");
delay(1000);
gw.present(TEMP_CHILD, S_TEMP);
Serial.println("presenting Thermometer");
delay(1000);
metric = gw.getConfig().isMetric;
Serial.println("requesting Metric");
delay(1000);
Serial.println("Setup Complete");
}

void loop()
{
if(!BaroSensor.isOK())
{
Serial.print("Sensor not Found/OK. Error: ");
Serial.println(BaroSensor.getError());
BaroSensor.begin(); // Try to reinitialise the sensor if we can
}

float pressure = BaroSensor.getPressure()/100;
float temperature = BaroSensor.getTemperature();
if (!metric)
{
// Convert to fahrenheit
temperature = temperature * 9.0 / 5.0 + 32.0;
}

int forecast = sample(pressure);

Serial.print("Temperature = ");
Serial.print(temperature);
Serial.println(metric?" C":" F");
Serial.print("Pressure = ");
Serial.print(pressure);
Serial.println(" Pa");
Serial.println(weather[forecast]);

if (temperature != lastTemp) {
gw.send(tempMsg.set(temperature,1));
lastTemp = temperature;
}

if (pressure != lastPressure) {
gw.send(pressureMsg.set(pressure, 0));
lastPressure = pressure;
}

if (forecast != lastForecast)
{
gw.send(forecastMsg.set(weather[forecast]));
lastForecast = forecast;
}

/*
DP/Dt explanation

0 = "Stable Weather Pattern"
1 = "Slowly rising Good Weather", "Clear/Sunny "
2 = "Slowly falling L-Pressure ", "Cloudy/Rain "
3 = "Quickly rising H-Press", "Not Stable"
4 = "Quickly falling L-Press", "Thunderstorm"
5 = "Unknown (More Time needed)
*/

gw.sleep(SLEEP_TIME);
}

int sample(float pressure) {
// Algorithm found here
// http://www.freescale.com/files/sensors/doc/app_note/AN3914.pdf
if (minuteCount > 180)
minuteCount = 6;
pressureSamples[minuteCount] = pressure;
minuteCount++;

if (minuteCount == 5) {
// Avg pressure in first 5 min, value averaged from 0 to 5 min.
pressureAvg[0] = ((pressureSamples[1] + pressureSamples[2]
+ pressureSamples[3] + pressureSamples[4] + pressureSamples[5])
/ 5);
} else if (minuteCount == 35) {
// Avg pressure in 30 min, value averaged from 0 to 5 min.
pressureAvg[1] = ((pressureSamples[30] + pressureSamples[31]
+ pressureSamples[32] + pressureSamples[33]
+ pressureSamples[34]) / 5);
float change = (pressureAvg[1] - pressureAvg[0]);
if (firstRound) // first time initial 3 hour
dP_dt = ((65.0 / 1023.0) * 2 * change); // note this is for t = 0.5hour
else
dP_dt = (((65.0 / 1023.0) * change) / 1.5); // divide by 1.5 as this is the difference in time from 0 value.
} else if (minuteCount == 60) {
// Avg pressure at end of the hour, value averaged from 0 to 5 min.
pressureAvg[2] = ((pressureSamples[55] + pressureSamples[56]
+ pressureSamples[57] + pressureSamples[58]
+ pressureSamples[59]) / 5);
float change = (pressureAvg[2] - pressureAvg[0]);
if (firstRound) //first time initial 3 hour
dP_dt = ((65.0 / 1023.0) * change); //note this is for t = 1 hour
else
dP_dt = (((65.0 / 1023.0) * change) / 2); //divide by 2 as this is the difference in time from 0 value
} else if (minuteCount == 95) {
// Avg pressure at end of the hour, value averaged from 0 to 5 min.
pressureAvg[3] = ((pressureSamples[90] + pressureSamples[91]
+ pressureSamples[92] + pressureSamples[93]
+ pressureSamples[94]) / 5);
float change = (pressureAvg[3] - pressureAvg[0]);
if (firstRound) // first time initial 3 hour
dP_dt = (((65.0 / 1023.0) * change) / 1.5); // note this is for t = 1.5 hour
else
dP_dt = (((65.0 / 1023.0) * change) / 2.5); // divide by 2.5 as this is the difference in time from 0 value
} else if (minuteCount == 120) {
// Avg pressure at end of the hour, value averaged from 0 to 5 min.
pressureAvg[4] = ((pressureSamples[115] + pressureSamples[116]
+ pressureSamples[117] + pressureSamples[118]
+ pressureSamples[119]) / 5);
float change = (pressureAvg[4] - pressureAvg[0]);
if (firstRound) // first time initial 3 hour
dP_dt = (((65.0 / 1023.0) * change) / 2); // note this is for t = 2 hour
else
dP_dt = (((65.0 / 1023.0) * change) / 3); // divide by 3 as this is the difference in time from 0 value
} else if (minuteCount == 155) {
// Avg pressure at end of the hour, value averaged from 0 to 5 min.
pressureAvg[5] = ((pressureSamples[150] + pressureSamples[151]
+ pressureSamples[152] + pressureSamples[153]
+ pressureSamples[154]) / 5);
float change = (pressureAvg[5] - pressureAvg[0]);
if (firstRound) // first time initial 3 hour
dP_dt = (((65.0 / 1023.0) * change) / 2.5); // note this is for t = 2.5 hour
else
dP_dt = (((65.0 / 1023.0) * change) / 3.5); // divide by 3.5 as this is the difference in time from 0 value
} else if (minuteCount == 180) {
// Avg pressure at end of the hour, value averaged from 0 to 5 min.
pressureAvg[6] = ((pressureSamples[175] + pressureSamples[176]
+ pressureSamples[177] + pressureSamples[178]
+ pressureSamples[179]) / 5);
float change = (pressureAvg[6] - pressureAvg[0]);
if (firstRound) // first time initial 3 hour
dP_dt = (((65.0 / 1023.0) * change) / 3); // note this is for t = 3 hour
else
dP_dt = (((65.0 / 1023.0) * change) / 4); // divide by 4 as this is the difference in time from 0 value
pressureAvg[0] = pressureAvg[5]; // Equating the pressure at 0 to the pressure at 2 hour after 3 hours have past.
firstRound = false; // flag to let you know that this is on the past 3 hour mark. Initialized to 0 outside main loop.
}

if (minuteCount < 35 && firstRound) //if time is less than 35 min on the first 3 hour interval.
return 5; // Unknown, more time needed
else if (dP_dt < (-0.25))
return 4; // Quickly falling LP, Thunderstorm, not stable
else if (dP_dt > 0.25)
return 3; // Quickly rising HP, not stable weather
else if ((dP_dt > (-0.25)) && (dP_dt < (-0.05)))
return 2; // Slowly falling Low Pressure System, stable rainy weather
else if ((dP_dt > 0.05) && (dP_dt < 0.25))
return 1; // Slowly rising HP stable good weather
else if ((dP_dt > (-0.05)) && (dP_dt < 0.05))
return 0; // Stable weather
else
return 5; // Unknown
}

[BulldogLowell]

@Myles-L

hard to read your code like that...

indent your code 4 spaces or put it between three ` [backwards apostrophe just left of the 1 on your keyboard]

are you sure your serial monitor is set to the correct speed?

I'd leave compilable alone until you get the devices set up... you didn't delete the vera devices after you got them set with the correct device number before, right?

[Myles L]

I did delete it but understand now why I shouldn't have. I will re-add it (different device id) and let you know. It may take a little while as I am waiting for some radios with external antennas and an finding in the meantime that my radio reception is too limited to proceed.