Weather Station Ideas

[Gina]

Here is the speed and direction code.  The sketch compiles fine but can't be sure I've got the maths right.

void do3sJobs (){
  windSpeed = ++PulseCount;  //  Accumulate mean speed
  if (PulseCount > windGust) {windGust = PulseCount;};  // Get max speed for gust
  PulseCount = 0;
  ++bin[readDirection()]; // increment appropriate bin
}
void do1mJobs(){
  // wind speed mean and gust ring arrays and report
  meanArray[ringIndex] = windSpeed; // put windSpeed into new array index
  gustArray[ringIndex] = windGust;  // put windGust into new array index
//  windSpeed /=20;  // leave this for later
  for (int i = 0; i < 10; i++) {
    meanSpeed += meanArray[i];  // add all windSpeeds 
    if (gustArray[i] > gustSpeed){gustSpeed = gustArray[i];}; // find maximum gust speed
  }
  meanSpeed /=200;  // the first sum was over 20 values and then the second over 10 values
  sendSpeedMessages();
  windGust = 0;
  ringIndex = (ringIndex+1)%10; // move ringIndex on to next location in the ring array
}
void do3mJobs(){
  // wind direction calculations and report
  int sum[16];
  int S=0,I=0,W=0;
  bin[16] = bin[0];
  bin[17] = bin[1];
  bin[18] = bin[2];
  bin[19] = bin[3];
  for (int i = 0; i < 16; i++) {
    sum[i] = bin[i] + bin[i+1] + bin[i+2] + bin[i+3] + bin[i+4];
    // find the index with the highest sum and save sum and index
    if (sum[i] > S){S = sum[i]; I = i;}; 
  }
  W = (bin[I+1] + 2 * bin[I+2] + 3 * bin[I+3] + 4 * bin[I+4]) * 45 / S;
  sendDirectionMessage((I * 45 + W)%720 /2);
}
void loop() {
  if (!client.connected()) {
    reconnect();
  }
  client.loop();

  long now = millis();
  if(now - last3s > P3s) {do3sJobs; last3s = now;}
  if(now - last1m > P1m) {do1mJobs; last1m = now;}
  if(now - last3m > P3m) {do3mJobs; last3m = now;}
}

May be able to test it tomorrow.  That's it for tonight.

[Gina]

Surprise, surprise - it doesn't work!!  Guess I'm going to have to put debug messages in to see what's happening.

Have it set up on the living room table.

MQTT Explorer is not showing any of the 5 wind messages.

Edited August 29, 2020 by Gina

[Gina]

First test - sending the instantaneous wind direct every 3 seconds.

void do3sJobs (){
  sendDirectionMessage(readDirection()); // send instantaneous direction

Later...  NOT working - nothing!!!

Have to try something simpler!

Edited August 29, 2020 by Gina

[Gina]

Found the silly mistake!!!

[Mr Spock]

20 minutes ago, Gina said:

Found the silly mistake!!!

Don't keep us in suspense! What was it?

 

[Gina]

Wrong

void loop() {
  if (!client.connected()) {
    reconnect();
  }
  client.loop();

  long now = millis();
  if(now - last3s > P3s) {do3sJobs; last3s = now;}
  if(now - last1m > P1m) {do1mJobs; last1m = now;}
  if(now - last3m > P3m) {do3mJobs; last3m = now;}
}

Right - missed out the () in the doxxJobs calls.  Doh!!

void loop() {
  if (!client.connected()) {
    reconnect();
  }
  client.loop();

  long now = millis();
  if(now - last3s > P3s) {do3sJobs(); last3s = now;}
  if(now - last1m > P1m) {do1mJobs(); last1m = now;}
  if(now - last3m > P3m) {do3mJobs(); last3m = now;}
}

 

[Gina]

Some of it seems to be working.  Direction and Gust speed but not Mean speed.

[Gina]

Actually, none of it is working correctly!!  I've turned the fan off so the speed is zero.  The direction is now something like 180° different and this hasn't shown up.  I can see this is going to take a lot of debugging.  And it's not as if I can put breakpoints in the code and debug it in the normal way.  I shall have send messages to the MQTT network at strategic points in the calculations.

[Gina]

Checking mean and gust speeds at the 1m point.

void do3sJobs (){
  windSpeed = ++PulseCount;  //  Accumulate mean speed
  if (PulseCount > windGust) {windGust = PulseCount;};  // Get max speed for gust
  PulseCount = 0;
  ++bin[readDirection()]; // increment appropriate bin
}
void do1mJobs(){
  // debugging - send current mean and gust speeds
  meanSpeed = windSpeed;  gustSpeed = windGust;
  sendSpeedMessages();

The results are wrong.  All speeds are showing 1 rather than 0 with no fan running.  Gust speed looks reasonable looking at the anemometer revs though 1 higher than it should be.  The Mean speed should show around 20 times the real value as the value is the sum of 20 counts and hasn't been divided.

It points to this line

  windSpeed = ++PulseCount;  //  Accumulate mean speed

From Arduino reference

Example Code

x = 2;
y = ++x;  // x now contains 3, y contains 3
y = x++;  // x contains 4, but y still contains 3

I can see what's wrong.

Got the wrong operator, should be

x += y; // equivalent to the expression x = x + y;

Corrected

  windSpeed += PulseCount;  //  Accumulate mean speed

 

[Gina]

About to run this code

void do3sJobs (){
//  sendDirectionMessage(readDirection()); // send instantaneous direction
  windSpeed += PulseCount;  //  Accumulate mean speed
  if (PulseCount > windGust) {windGust = PulseCount;};  // Get max speed for gust
  PulseCount = 0;
  ++bin[readDirection()]; // increment appropriate bin
}
void do1mJobs(){
  // debugging - send current mean and gust speeds
  meanSpeed = windSpeed/20;  gustSpeed = windGust;
  windSpeed = 0;
  sendSpeedMessages();

 

[Gina]

This looks better.

[Gina]

Looking at the direction.  Might be right.

[Gina]

I think the wind direction may be correct.  The instantaneous direction is varying between WSW and W - 11 & 12 points or 247.5° and 270°.  The mean direction is reading 261° which agrees (it is between 247.5 and 270).

The wind mean speed is a different matter!!  It isn't working!   This is the averaging in the ring array.  OTOH the Gust speed does seem to be working.

[Gina]

For debugging I have added a number display in the Wind tab.  Currently showing the ringIndex and that is correct - starting at 0, increasing up to 9 and then back to 0.  The mean and gust displays are increasing with every change in index though so I have another error (or two).  Clearly not zeroing the values before forming sum and maximum.

Edited August 29, 2020 by Gina

[Gina]

Corrected that error and the gust speed is reading correctly but the mean speed is still increasing.  So still an error!!  Somewhere in this section of code.

void do1mJobs(){
  // wind speed mean and gust ring arrays and report
  meanArray[ringIndex] = windSpeed; // put windSpeed into new array index
  gustArray[ringIndex] = windGust;  // put windGust into new array index
//  windSpeed /=13;  // /20 and *1.5 -- leave this for later
  meanSpeed = 0; gustSpeed = 0;
  for (int i = 0; i < 10; i++) {
    meanSpeed += meanArray[i];  // add all windSpeeds 
    if (gustArray[i] > gustSpeed){gustSpeed = gustArray[i];}; // find maximum gust speed
  }
  meanSpeed /=133;  // the first sum was over 20 values and then the second over 10 values
  gustSpeed *= 1.5;  // Speed count over 3s rather than 4.5s
  sendSpeedMessages();  // HOLD temporarily for debugging
  windGust = 0;
  sendNumberMessage(ringIndex);  //  send ringIndex for debugging
  ringIndex = (ringIndex+1)%10; // move ringIndex on to next location in the ring array
}

 

[Gina]

I think I need to see what's going into the ring array.

[Gina]

Seems to be working correctly now.

[Gina]

I'll just confirm that all compass points for the wind vane give sensible results then look to installing the wind sensors and mast.

Later...  Should have guessed it was too good to be true.  OK yes the speed processing seems fine but the direction isn't!  I had posted the sketch but now removed it as it isn't right.

Switched the fan off and let the anemometer slow down and stop then moved the vane to the 0 position.  I have given the Consensus Averaging time to work and for the wind speed to decay from the ring arrays.  This is the result.

Yes!!  It's a long way off right!!  So now I have more debugging to do!  Though not tonight I don't think.

Edited August 29, 2020 by Gina

[Gina]

Seems as if the mean direction is bearing no relationship to the actual wind vane direction.  The instantaneous direction is correct so the encoder is working fine - it's the Consensus Averaging calculations that are wrong.  Somewhere in all that code!!

Edited August 29, 2020 by Gina

[Gina]

Found the problem.  Forgot to empty the bins after counting the hits ready for the next lot.  Added this line and it seems to be working correctly.

  for (int i = 0; i < 16; i++) {bin[i] = 0;};

[Gina]

Next I need to adjust the direction to suit the orientation of the wind instruments.  This could be done when reading the encoder or when displaying the results.  I guess the former is easiest.

Think this should do it.

    dirn = (dirn - 1) %16; // correct encoder for North

Edited August 30, 2020 by Gina

[Gina]

Having thoroughly tested the wind sensors indoors and found everything seemingly correct I've installed them outside on the observatory and powered up.  BUT things are NOT right!!

[Gina]

The wind is very light and variable with anemometer rotating at around 1rps or less so not every 3s period getting a pulse.  This could be the reason, I guess, though how the instantaneous direction could be over 15 when there's a modulo 16, I don't know!

Sometimes the display seems right.

Edited August 30, 2020 by Gina

[Gina]

The anemometer is very sensitive and turns smoothly at well under 1 mph so the mean speed could be displayed in tenths but I guess there's really no point (no pun intended).

The Beaufort scale for wind force is a good indicator but really I would like more points.

Edited August 30, 2020 by Gina

[Gina]

I'm copying a post here as I don't know the best place for it.

1 minute ago, Gina said:

I'm getting a strange problem with the wind speed.  Whether this is anything to do with MQTT or just the sketch in the wind ESP32 I don't know.  Until today the speed calculations have been fine but now the mean speed keeps resetting then building up again to the correct value.  These are enlargements of the mean speed history in the dashboard and the MQTT Explorer.   I'm wondering if the stronger breeze today could be anything to do with it. 

Unfortunately, to upload a new sketch to the ESP32 in the wind client means taking the wind sensor mast and unit down and connecting the ESP32 to the Mint box USB.  I seem to remember reading something about uploading a new Arduino sketch over WiFi but can't find it now.