[David De Laet]

Hi,

For the power consumption I still need to some extra measuring.
The heat in my enclosure was +-1.5°C higher than a sensor without enclosure on 240Mhz
It lowered down to +-1.1 °C on 160Mhz. Unfortunately this is not an constant value as this depends on the room temp. Or I have to design a bigger case where the ESP and DHT are even more separated.

My thoughts was to run an XML/SOAP server or any other usable protocol on the ESP/relay , which receives sensor data from multiple ESP/DHT.
Where the ESP/DHT polls the temp, sends it to the Relay ESP, and goes back to deep sleep.(for example every minute or even longer). This should lower the power consumption to a point where it could operate on a battery. There is a easy to understand guide for how and why: https://www.youtube.com/watch?v=heD1zw3bMhw

As for a radiator head we need an “mini” linear actuator that can be controller by 0-100 value with a small controller; ESP32 or other controller. The radiator has a small metal pin when pushed the valve closes and visa versa.
To drive a small motor we only need a NPN transistor, 1 resistor and one diode. (only on or off type)
If we want to know the position of the motor, we need a stepper motor and this can be driven by a driver on chip, for example the L293 series.

Example of a slightly bigger linear motor.

I have designed some electronic boards in fritzing, but mostly for hobby purposes.

There are also commercial versions of this system. Unfortunately closed, expensive and thus no fun!
https://www.fibaro.com/en/products/the-heat-controller/

These where just some thoughts for a fun hobby project.
PS: name is David De Laet from Belgium.

[David De Laet]

.ino files where not allow to upload. trying .txt

Attachments:

1. smartthermo_esp_dht_clean.txt

[David De Laet]

Hi,

I changed the code to a specific ESP/DHT library. https://github.com/beegee-tokyo/DHTesp
– Added time stamp logging to the serial port.
– Scaled down the CPU to 160Mhz instead of 240Mhz (line 57; Change RTC_CPU_FREQ_160M to RTC_CPU_FREQ_240M etc.. )
for lower power consumption and heat.
– Added the error status in the logging header, and a status drop when it fails.
– Auto detect Sensor type, or manual selection for DHT11, DHT22, AM2302, RHT03.

Things I could improve:
– Fahrenheit <-> Celsius conversion is built in the library and could be simplified.
– Maybe multiple sensors on a second webserver port?
– Code cleanup

Some features I would like to look in for feasibility if time permits 🙂
– Deep sleep by using one Sensor collector (for example the ESP32_RELAY)
Send the Sensor data to the collector by low power BT or WIFI.
– Designing a thermostat head to control separate radiators.

And of course you can use my code 🙂
Let me know if you can use any of the code.

Greetz,
David

• This reply was modified 6 years, 9 months ago by David De Laet.
• This reply was modified 6 years, 9 months ago by David De Laet.

[David De Laet]

Hi,

Indeed this the lib I used.

This is code I changed, still quick & dirty, as I wanted to wait your response before I would clean the code up and add some more error catching. As this code is your work, I wanted you to have the final word 🙂 although I’m happy to help..

int chk = SimpleDHTErrSuccess;
double celsiusTemp = -10000;
double fahrenheitTemp = -10000;
float temperature = 0;
float humidity = 0;
if (DHTTYPE == 22) {
chk = dht22.read2(DHTPin,&temperature, &humidity, NULL );

} else {
chk = dht11.read2(DHTPin,&temperature, &humidity, NULL );
}

if (chk == SimpleDHTErrSuccess) {
thError=””;
Serial.print(“DHT OK,\t”); Serial.print(“TempCelcius= “);
Serial.print((float)temperature); Serial.print(” C°\t”);
Serial.print(“Humidity= “);
Serial.print((float)humidity); Serial.print(“\t”);
celsiusTemp = (float)temperature;
fahrenheitTemp = celsius2Fahrenheit(celsiusTemp);

} else {
switch (chk)
{
case SimpleDHTErrDataChecksum:
thError = “Checksum error”;
break;

default:
thError = “Unknown error”;
break;
}
Serial.print(thError);
}

[David De Laet]

Hi,

I changed your code to use the SimpleDHT library, and added the temp readings to serial output.
Including catching the DHT errors, and had no timeouts anymore.

Ps: found a small bug in the app. If you leave the calibration value empty instead of an value, the app will crash.

Connecting to *********
….
WiFi connected
IP address: 192.168.60.50
MAC: ***********
New client
GET / HTTP/1.1
Host: 192.168.60.50
Connection: Keep-Alive
Accept-Encoding: gzip
User-Agent: okhttp/3.9.0

DHT OK, TempCelcius= 24.60 C° Humidity= 53.90 client disconnected
Tue Apr 3 17:31:26 2018

New client
GET / HTTP/1.1
Host: 192.168.60.50
Connection: Keep-Alive
Accept-Encoding: gzip
User-Agent: okhttp/3.9.0

DHT OK, TempCelcius= 24.60 C° Humidity= 53.40 client disconnected
Tue Apr 3 17:31:36 2018

New client
GET / HTTP/1.1
Host: 192.168.60.50
Connection: Keep-Alive
Accept-Encoding: gzip
User-Agent: okhttp/3.9.0

DHT OK, TempCelcius= 24.50 C° Humidity= 53.20 client disconnected
Tue Apr 3 17:31:46 2018

New client
GET / HTTP/1.1
Host: 192.168.60.50
Connection: Keep-Alive
Accept-Encoding: gzip
User-Agent: okhttp/3.9.0

DHT OK, TempCelcius= 24.60 C° Humidity= 53.20 client disconnected
Tue Apr 3 17:31:56 2018

New client
GET / HTTP/1.1
Host: 192.168.60.50
Connection: Keep-Alive
Accept-Encoding: gzip
User-Agent: okhttp/3.9.0

DHT OK, TempCelcius= 24.60 C° Humidity= 53.20 client disconnected
Tue Apr 3 17:32:06 2018

New client
GET / HTTP/1.1
Host: 192.168.60.50
Connection: Keep-Alive
Accept-Encoding: gzip
User-Agent: okhttp/3.9.0

DHT OK, TempCelcius= 24.60 C° Humidity= 53.20 client disconnected
Tue Apr 3 17:32:16 2018

New client
GET / HTTP/1.1
Host: 192.168.60.50
Connection: Keep-Alive
Accept-Encoding: gzip
User-Agent: okhttp/3.9.0

DHT OK, TempCelcius= 24.60 C° Humidity= 53.10 client disconnected
Tue Apr 3 17:32:26 2018

New client
GET / HTTP/1.1
Host: 192.168.60.50
Connection: Keep-Alive
Accept-Encoding: gzip
User-Agent: okhttp/3.9.0

DHT OK, TempCelcius= 24.60 C° Humidity= 53.00 client disconnected
Tue Apr 3 17:32:36 2018

New client
GET / HTTP/1.1
Host: 192.168.60.50
Connection: Keep-Alive
Accept-Encoding: gzip
User-Agent: okhttp/3.9.0

DHT OK, TempCelcius= 24.60 C° Humidity= 53.00 client disconnected
Tue Apr 3 17:32:46 2018

New client
GET / HTTP/1.1
Host: 192.168.60.50
Connection: Keep-Alive
Accept-Encoding: gzip
User-Agent: okhttp/3.9.0

DHT OK, TempCelcius= 24.60 C° Humidity= 53.00 client disconnected
Tue Apr 3 17:32:56 2018

New client
GET / HTTP/1.1
Host: 192.168.60.50
Connection: Keep-Alive
Accept-Encoding: gzip
User-Agent: okhttp/3.9.0

DHT OK, TempCelcius= 24.60 C° Humidity= 53.00 client disconnected
Tue Apr 3 17:33:06 2018

[David De Laet]

Hi,

Indeed, after adding a time stamp to the sketch, I see a poll every 10 sec. 🙂
I assumed a polling issue, as many people on esp32 forums had this problem. My bad..

Below the time stamp logs. I will try with another DHT lib en post the results.
New client
GET / HTTP/1.1
Host: 192.168.60.50
Connection: Keep-Alive
Accept-Encoding: gzip
User-Agent: okhttp/3.9.0

DHT OK, client disconnected
Tue Apr 3 18:35:55 2018

New client
GET / HTTP/1.1
Host: 192.168.60.50
Connection: Keep-Alive
Accept-Encoding: gzip
User-Agent: okhttp/3.9.0

DHT OK, client disconnected
Tue Apr 3 18:36:05 2018

New client
GET / HTTP/1.1
Host: 192.168.60.50
Connection: Keep-Alive
Accept-Encoding: gzip
User-Agent: okhttp/3.9.0

DHT OK, client disconnected
Tue Apr 3 18:36:15 2018

New client
GET / HTTP/1.1
Host: 192.168.60.50
Connection: Keep-Alive
Accept-Encoding: gzip
User-Agent: okhttp/3.9.0

DHT OK, client disconnected
Tue Apr 3 18:36:25 2018

New client
GET / HTTP/1.1
Host: 192.168.60.50
Connection: Keep-Alive
Accept-Encoding: gzip
User-Agent: okhttp/3.9.0

Timeout errorclient disconnected
Tue Apr 3 18:36:35 2018

[David De Laet]

Hi,

I am using the DHT22 board from keyes. I do have some timeout errors, 1 out of 5 polls.
I’m looking at the sketch, with the Serial Console..
My first impression is that we are polling to fast, the DHT22 can only be polled every 2 sec. (2.5 to be safe) I would even poll only every minute.
I have added time stamps into the code for debugging, and will try some other dht libraries this evening.

Mvg,

[David De Laet]

Added some extra details of the drawing.

Attachments:

1. 

   Sensor_boxDHT_lid.png
   

2. 

   Sensor_box_DHT.png
   

3. 

   Sensor_box_esp.png
   

[David De Laet]

The stl files will be available soon on thingiverse.
If someone want a printed version, I could send one for the price of filament, electricity & shipping costs.

Attachments:

1. 

   Sensor_box-v1.png
   

[David De Laet]

The first version of the sensor box is ready.
All the pins are soldered, and is assembled with snap-ins.

and a wall mount bracket will be available soon.

Attachments:

1. 

   IMG_20180403_112751-1280x1280.jpg
   

2. 

   IMG_20180403_112848-1280x1280.jpg
   

3. 

   IMG_20180403_112932-1280x1280.jpg
   

4. 

   IMG_20180403_112958-1280x1280.jpg
   

[David De Laet]

Hi,

Indeed the calibration option is now working, thanks alot!

Gr,
David

[David De Laet]

Hi,

As requested, a pictures from inside the box. Don’t mind the extra cables, Converted a Default High to a Default low relay.

Red: VCC 5v -> esp32
White: Ground -> esp32
Yellow: Pin18 ->esp32
Purple: short COM+GND

Attachments:

1. 

   IMG_20180326_171625-1280x1280.jpg
   

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