💬 Air Humidity Sensor - DHT

[sundberg84]

@godwinguru - I dont know why but it seems like your gw is restarting. I dont know anything about a Raspberry GW so you need to wait for someone else to answer.

Top of my mind is a power issue.

Also I added ``` around your code which makes it easier for others to read. Please use this when you post logs.

[godwinguru]

@sundberg84, thank you for your reply, my gateway is Ethernet with arduino, am not using rhaspberry pi., thanks once again.

[sundberg84]

@godwinguru - then I would say you have a power issue. As something is using power the gw restarts due to this. What controller do you use? Do you see any connection status there? How do you power the gw? This is crucial that you use a capacitor on the radio and have a stable power supply för the radio.

[godwinguru]

@sundberg84, as i said, am new to mysensors, i dont know where and how to select a controller, it is in my mind to use homegenie, but i still dont know how to integrate it with the gateway, am using adapter to power it, it may not be power problem, i think i still to know a lot about how mysensors works. This is because i used this code (/mysensors/MySensors/examples/GatewayW5100/GatewayW5100.ino) on the gateway without changing anything. i doubt if that is okay, because i never added any other thing to the code.

[sundberg84]

@godwinguru - ok, then thats your problem. The GW cant be used on its own - it require a controller to work. The controller hand out ID and collect all the data. The controller can be used on a raspberry pi for example.

[Digdogger]

Hello,
problem, after each restart of gateway or restore database, all my temp/humity sensors are seen as 2 sensors.
Seen like that:
2017-07-15 15:23:53.758 (Mysensor) Temp (Temp)
2017-07-15 15:23:53.763 (Mysensor) Humidity (Hum)
Should be (on another sensor):
2017-07-15 15:26:45.610 (Mysensor) Temp + Humidity (Salon)

After 3 hours one sensor is still doing the same. I restarted it, no change.
Restarted the gateway again, no change. There is still one sensor which has this behaviour and it's never the same sensor...

[gohan]

It's a Domoticz problem, sometimes just rebooting everything can solve but try to search on domoticz forum too.

[cristi]

2 issues I see with the example:
a) I'm not a native english speaker, but to me, on top of the page, "sampling rate" of "2 times/sec" for dht-22 is wrong. From code and pdf you can see that you can't ask for data faster than at 2 seconds.
As such, I would change the top of the page to read either "0.5 times/sec" or "1 time at 2 seconds".

b) use of SENSOR_TEMP_OFFSET is wrong. Because depending on how the controller wants this sensor's data (Celsius | Fahrenheit), the offset will be different. If you happen to change the metric system value in the controller and ask for the data (after sensor restart let's say), you'll get a different value than expected).
I would do:

1. • add to the comment for SENSOR_TEMP_OFFSET that we're talking about a Celsius offset
2. • and move the statement "temperature += SENSOR_TEMP_OFFSET;" before the conversion to Fahrenheit.

Regards.

[mfalkvidd]

Thanks @cristi
I have updated the table with the sample rate. Could you check if it looks good?

For the code change a pull request will be needed. Could you do one? If you can't I'll add it to my todo but it might take a while.

[cristi]

@mfalkvidd

• there's a typo in the table for DHT-11: it should be '1s per sample' instead of '10s per sample'
• I created a pull request

[mfalkvidd]

@cristi according to http://www.micropik.com/PDF/dht11.pdf typical response time is 10s. Am I looking at the wrong number?

Great work on the pull request. I'm adding a link in case someone needs it in the future. https://github.com/mysensors/MySensorsArduinoExamples/pull/29/

[cristi]

@mfalkvidd Indeed, I see that 10 seconds in pdf, but it looks strange. I'd have to re-read to see if I can get what it is supposed to be for.
But, meanwhile, in the same pdf, you get this note (chapter 6): "Note: Sampling period at intervals should be no less than 1 second.". Also, DHT library is using 1second sampling period.

[mfalkvidd]

@cristi thanks. I have updated the table.

[ricmail85]

I've created a DHT11 sensor based on this sketch. However the temperatures (and humidities) are reported as integer numbers in domoticz (either by looking at the devices and setup tabs). In the sketch I've specified the number of decimals like send(msgHum.set(temperatire, 2)). Even if I try larger decimal numbers, nothing change when the value is received in domoticz. What can I do?
Thanks in advance.

[gohan]

What kind of variable did you set for your "temperature"? If you can post your code it would help

[mfalkvidd]

@ricmail85 you mean you're only getting integers here?

[ricmail85]

@mfalkvidd yes I see only integer numbers here and in devices.

@gohan I've declared the variable temperature as float. However after I bit of debugging I found that it seems to be related to the dht lib included in the mysensors examples. If the model is dht11 the library is set for 0 decimals. For the dht22 it would be 1 decimal.

Am I right? Thanks in advance

[scottdube]

NEWBIE ALERT -- Has anyone else had trouble getting the code above to compile? I'm getting the following error.

ysensors_Humidity:91: error: 'class DHT' has no member named 'setup'
dht.setup(DHT_DATA_PIN); // set data pin of DHT sensor
^
Mysensors_Humidity:92: error: 'class DHT' has no member named 'getMinimumSamplingPeriod'
if (UPDATE_INTERVAL <= dht.getMinimumSamplingPeriod()) {
^
Mysensors_Humidity:97: error: 'class DHT' has no member named 'getMinimumSamplingPeriod'
sleep(dht.getMinimumSamplingPeriod());
^
/Users/scottdube/Documents/Arduino/Mysensors_Humidity/Mysensors_Humidity.ino: In function 'void loop()':
Mysensors_Humidity:104: error: 'class DHT' has no member named 'readSensor'
dht.readSensor(true);
^
Mysensors_Humidity:107: error: 'class DHT' has no member named 'getTemperature'
float temperature = dht.getTemperature();
^
Mysensors_Humidity:114: error: 'class DHT' has no member named 'toFahrenheit'
temperature = dht.toFahrenheit(temperature);
^
Mysensors_Humidity:131: error: 'class DHT' has no member named 'getHumidity'
float humidity = dht.getHumidity();
^
exit status 1
no matching function for call to 'DHT::DHT()'

Thanks

[gohan]

I guess you are using a different dht library version

[scottdube]

@gohan I got it past that point... Now I can't tell what the humidity or temp is? I cannot seem to find where (what file) controls what is being output. See below this is from my serial gateway, I can't figure out what these values represent. :READ,255-255-0,s=36,c=3,t=3,pt=0,l=0,sg=0:
255;36;3;0;3;

0;255;3;0;9;0 MCO:BGN:INIT GW,CP=RNNGA---,VER=2.2.0
0;255;3;0;9;4 TSM:INIT
0;255;3;0;9;6 TSF:WUR:MS=0
0;255;3;0;9;14 TSM:INIT:TSP OK
0;255;3;0;9;17 TSM:INIT:GW MODE
0;255;3;0;9;20 TSM:READY:ID=0,PAR=0,DIS=0
0;255;3;0;9;23 MCO:REG:NOT NEEDED
0;255;3;0;14;Gateway startup complete.
0;255;0;0;18;2.2.0
0;255;3;0;9;28 MCO:BGN:STP
0;255;3;0;9;34 MCO:BGN:INIT OK,TSP=1
0;255;3;0;9;30224 TSF:MSG:READ,255-255-255,s=255,c=3,t=7,pt=0,l=0,sg=0:
0;255;3;0;9;30231 TSF:MSG:BC
0;255;3;0;9;30233 TSF:MSG:FPAR REQ,ID=255
0;255;3;0;9;30237 TSF:PNG:SEND,TO=0
0;255;3;0;9;30240 TSF:CKU:OK
0;255;3;0;9;30243 TSF:MSG:GWL OK
0;255;3;0;9;30832 TSF:MSG:SEND,0-0-255-255,s=255,c=3,t=8,pt=1,l=1,sg=0,ft=0,st=OK:0
0;255;3;0;9;32237 TSF:MSG:READ,255-255-0,s=36,c=3,t=3,pt=0,l=0,sg=0:
255;36;3;0;3;
0;255;3;0;9;34249 TSF:MSG:READ,255-255-0,s=1,c=3,t=3,pt=0,l=0,sg=0:
255;1;3;0;3;
0;255;3;0;9;36260 TSF:MSG:READ,255-255-0,s=220,c=3,t=3,pt=0,l=0,sg=0:
255;220;3;0;3;
0;255;3;0;9;38270 TSF:MSG:READ,255-255-0,s=183,c=3,t=3,pt=0,l=0,sg=0:
255;183;3;0;3;