💬 Temperature Sensor

[skywatch]

@mfalkvidd said in Temperature Sensor:
Thank you very much for helping out with this! - I will try it today if I can. I guess I could use the same principle to send sensor data every 2 minutes instead of every 1 minute and further reduce battery draw. I know the DS18B20 sensors are correctly going into sleep mode, but the node itself is still using too much juice.

@skywatch doing what you want is a bit hard since millis won't update while the node is in power save mode (sleeping).

There is nothing in the API about this, would be nice if it were added as I don't think I will be the only person with such requirements. Also, what does sleep actually do and are there further things I could do to reduce the power use?

I don't understand why you're using interrupt to sleep though.

That is because I haven't finished this node yet.... I am working on it systematically and in future a water leak detector will be added. But only when this part is working correctly and I have good battery life from the node.

[mfalkvidd]

@skywatch said in Temperature Sensor:

There is nothing in the API about this, would be nice if it were added as I don't think I will be the only person with such requirements.

Good point. I have added a note on https://www.mysensors.org/download/sensor_api_20#sleeping

Also, what does sleep actually do and are there further things I could do to reduce the power use?

It does a lot of things, but basically it puts the radio and the Arduino in power save mode and uses the Arduino's watchdog timer to roughly keep track of time (exact timing is not possible because exact timing requires power, and power save mode is all about saving power).

https://www.mysensors.org/build/battery has the official MySensors recommendations on how to save power in battery-operated nodes.

If you want to dive deeper, start with https://www.gammon.com.au/power

[gohan]

I'd use the sleep time to 2 minutes and then simply set a counter that every 15 loops of the code sends battery status and resets the counter. Imho 2 minutes are quite often for battery life.

[mfalkvidd]

@gohan wasn't that what I did?

[skywatch]

This can't be right, can it???

(http://imagebucket.net/7mtp8rcnqss2/BattGraph.jpg)

[gohan]

@mfalkvidd I'm on mobile, I didn't read the code

[mfalkvidd]

@skywatch it looks normal. The precision is probably 1% and the real value close to 100.5%, so sometimes it will be rounded to 101% and sometimes to 100%.

[mfalkvidd]

@gohan hek has added a great feature that I use a lot on mobile. Click the code box once to maximize it. Super neat!

[skywatch]

@mfalkvidd,

Did you notice the time line on the bottom of the image. I thought it was supposed to send data once every 30 mins. Seems that something isn't right or I am looking at it from the wrong angle.....?

[mfalkvidd]

@skywatch I'm not that versed in c/c++ arithmetic, but I suspect the calculation might overflow. Could you add a debug print to see the value of batteryReportFactor?

[skywatch]

OK I'll do that - seems to be sending battery info every minute still though- strange!

[mfalkvidd]

@skywatch could you post the entire sketch also, to check if something fishy has crept in?

[skywatch]

Here is the sketch, debug will be later today I hope....

// Enable debug prints to serial monitor
//#define MY_DEBUG

// Enable and select radio type attached
#define MY_RADIO_NRF24
//#define MY_RADIO_RFM69
#define COMPARE_TEMP 1 // Send temperature only if changed? 1 = Yes 0 = No
#define MY_RF24_PA_LEVEL (RF24_PA_LOW)
#define ONE_WIRE_BUS 3 // Pin where dallase sensor is connected 
#define MAX_ATTACHED_DS18B20 3
#include <SPI.h>
#include <MySensors.h>
#include <DallasTemperature.h>
#include <OneWire.h>
int BATTERY_SENSE_PIN = A0;  // select the input pin for the battery sense point
int batteryPcnt = 0;
unsigned long SLEEP_TIME = 2 * 60 * 1000; // 2 minutes Sleep time between reads.
OneWire oneWire(ONE_WIRE_BUS); // Setup a oneWire instance to communicate with any OneWire devices (not just Maxim/Dallas temperature ICs)
DallasTemperature sensors(&oneWire); // Pass the oneWire reference to Dallas Temperature.
float lastTemperature[MAX_ATTACHED_DS18B20];
int numSensors = 0;
const long interval = 90000;
unsigned long previousMillis = 0;
bool receivedConfig = false;
bool metric = true;
unsigned int batteryReportFactor = 30*60*1000/SLEEP_TIME; // Only report battery every x SLEEP times (x=15 with current values)
unsigned int timesSlept = 0;
// Initialize temperature message
MyMessage msg(0, V_TEMP);

void before()
{
  // Startup up the OneWire library
  sensors.begin();
}

void setup()
{
  // requestTemperatures() will not block current thread
  sensors.setWaitForConversion(false);
  analogReference(INTERNAL);
}

void presentation() {
  // Send the sketch version information to the gateway and Controller
  sendSketchInfo("HW/CH", "0.5");

  // Fetch the number of attached temperature sensors
  numSensors = sensors.getDeviceCount();

  // Present all sensors to controller
  for (int i = 0; i < numSensors && i < MAX_ATTACHED_DS18B20; i++) {
    present(i, S_TEMP);
  }
}

void loop()
{
  // get the battery Voltage
  if (timesSlept < batteryReportFactor) {
    timesSlept++;
  } else {
    // get the battery Voltage
    timesSlept = 0;
    int sensorValue = analogRead(BATTERY_SENSE_PIN);
    batteryPcnt = sensorValue / 10;
    sendBatteryLevel(batteryPcnt);
  }

  // Fetch temperatures from Dallas sensors
  sensors.requestTemperatures();

  // query conversion time and sleep until conversion completed
  int16_t conversionTime = sensors.millisToWaitForConversion(sensors.getResolution());
  // sleep() call can be replaced by wait() call if node need to process incoming messages (or if node is repeater)
  sleep(conversionTime);

  // Read temperatures and send them to controller
  for (int i = 0; i < numSensors && i < MAX_ATTACHED_DS18B20; i++) {

    // Fetch and round temperature to one decimal
    float temperature = static_cast<float>(static_cast<int>((getControllerConfig().isMetric ? sensors.getTempCByIndex(i) : sensors.getTempFByIndex(i)) * 10.)) / 10.;

    // Only send data if temperature has changed and no error
#if COMPARE_TEMP == 1
    if (lastTemperature[i] != temperature && temperature != -127.00 && temperature != 85.00) {
#else
    if (temperature != -127.00 && temperature != 85.00) {
#endif

      // Send in the new temperature
      send(msg.setSensor(i).set(temperature, 1));
      // Save new temperatures for next compare
      lastTemperature[i] = temperature;
    }
  }

  int8_t sleep(1, FALLING, SLEEP_TIME);
}```

Thanks!

[mfalkvidd]

@skywatch code looks good to me. What type of Arduino are you using?

[skywatch]

I am using a pro mini 3.3v 8MHz. I would ideally like to get a 1MHZ bootloader onto it but the last try stopped the temperature sensors sending data (although battery levels were still sent!)..... Hope it helps.

[mfalkvidd]

@skywatch could you also print the return value of the sleep function. Maybe that interrupt is triggering it so it returns early?

[skywatch]

Sorry for the dealy, I have had a week of plumbing problems at home - yuck!

So, I came back fresh to this and noticed that I had put the interrupt into the code ready for the water leak sensor (apt considering this weeks activities!) - BUT, I had not assigned the pin nor initialised it in the code. So maybe it was floating and giving random triggers?
I tested by changing from int8_t sleep(1, FALLING, SLEEP_TIME); to int8_t sleep(SLEEP_TIME); but now I get battery level sent every single second! - This is making me crazy......

The log for the gateway has the following.....

Sep  3 07:00:37 HAAS rsyslogd-2007: action 'action 17' suspended, next retry is Sun Sep  3 07:02:07 2017 [try http://www.rsyslog.com/e/2007 ]
Sep  3 06:26:28 HAAS rsyslogd0: action 'action 17' resumed (module 'builtin:ompipe') [try http://www.rsyslog.com/e/0 ]
Sep  3 06:26:28 HAAS rsyslogd-2359: action 'action 17' resumed (module 'builtin:ompipe') [try http://www.rsyslog.com/e/2359 ]

Not sure what the above is all about. Nor the below....

7:15:45 HAAS dhcpcd[474]: eth0: Router Advertisement from fe80::3291:8fff:fe06:64bc

But here is sending data every second.....

Sep  3 12:46:52 HAAS mysgw: TSF:MSG:READ,5-5-0,s=255,c=3,t=0,pt=1,l=1,sg=0:75
Sep  3 12:46:53 HAAS mysgw: TSF:MSG:READ,5-5-0,s=255,c=3,t=0,pt=1,l=1,sg=0:75
Sep  3 12:46:54 HAAS mysgw: TSF:MSG:READ,5-5-0,s=255,c=3,t=0,pt=1,l=1,sg=0:75
Sep  3 12:46:55 HAAS mysgw: TSF:MSG:READ,5-5-0,s=255,c=3,t=0,pt=1,l=1,sg=0:75
Sep  3 12:46:56 HAAS mysgw: TSF:MSG:READ,5-5-0,s=255,c=3,t=0,pt=1,l=1,sg=0:75
Sep  3 12:46:57 HAAS mysgw: TSF:MSG:READ,5-5-0,s=255,c=3,t=0,pt=1,l=1,sg=0:75
Sep  3 12:46:58 HAAS mysgw: TSF:MSG:READ,5-5-0,s=255,c=3,t=0,pt=1,l=1,sg=0:75
Sep  3 12:46:59 HAAS mysgw: TSF:MSG:READ,5-5-0,s=255,c=3,t=0,pt=1,l=1,sg=0:75
Sep  3 12:47:00 HAAS mysgw: TSF:MSG:READ,5-5-0,s=255,c=3,t=0,pt=1,l=1,sg=0:75

Will try debug on node next....

[skywatch]

I.m sure it is a bug in 2.2.0-beta as I have the same issues with another node sending data whenever it changes and not sleeping.

[dertho]

Hi,

is there any known problem / bug with version 2.1.* and the Dallas temp sensor? (I found non in the bug tracker and/or forum)

I updated several nodes from 1.5 to 2.1.1 and now no temp sensor is working. No temp sensor DS18B20 is found by the node, therefore -127.0 is returned to the controller. I checked the wiring - as illustrated in this manual, everything seems right; incl. the pull-up with 4,7 k. I use the modified version of the Dallas-Library included in the examples package, as stated out in this manual.

Thanks,
Thomas

[Mohammed Zaman]

I am not a programmer, but trying to learn by making small projects.
I am trying to build a arduino/ESP8266 with temp sensor so that at a particular set temp it sends a single to another arduino/ESP8266 with relay to turn on a cooler/heater. if there is a thread on this, please help me find it.

[rejoe2]

@Mohammed-Zaman This seems to be possible, you may find more info wrt your topic using "node to node communication" as a keyword for searching the forum.
This might be a good starting point: https://forum.mysensors.org/topic/6386/almost-controller-less-mysensors-switch-light-network/8#

[gohan]

https://forum.mysensors.org/topic/7810/alternative-passive-mode if you don't want to use a gateway.

[sjoerd14]

regarding error:

C:\Users\Admin\Documents\Arduino\libraries\DallasTemperature/DallasTemperature.h:249:13: error: 'int16_t DallasTemperature::millisToWaitForConversion(uint8_t)' is private

In the latest version of Miles Burton's the function is public and compiling fine.
https://github.com/milesburton/Arduino-Temperature-Control-Library

You can import the Lib as zip.
You have to remove \ archive the lib: ...\libraries\DallasTemperature

[mfalkvidd]

@sjoerd14 yes, thanks to MySensors user David Ducatel. The change is tracked in https://github.com/mysensors/MySensorsArduinoExamples/issues/20 and https://github.com/milesburton/Arduino-Temperature-Control-Library/pull/72 but we're still waiting for an official release of milesburton's library.

[nofox]

Hi, I have few in wall nodes mounted under the light switches. I have two relays and one DS18B20 in each node. When i'm turning light on, switching the relay, the DS18B20 readings jumping about 0.8 degrees celsius up. When I switch off the relay readings back to normal. Anyone have similar problems ? Sensors are away from from node board, relays etc. so it's not about the heat from atmega or relays.

[gohan]

Is the temperature gradually rising after the relay is activated or it is instantly jumping 0.8°?

[nofox]

Jumping 0.8 immediately after switching the relay and sometimes rising very slow during the time when relay is on.

[gohan]

That makes it quite difficult to figure out the problem. Can you make another node with same setup and see if you get the same results and if you do try unplug the relay and see what happens

[skywatch]

It's probably a voltage drop from the psu when the relay is engaged and drawing current. That will cause the output voltage to dip slightly.

If it is only momentary you can add a beefy capacitor across the power supply, but if the readings change for the whole time the relay is on, you really need to replace the relay with something that uses less power (triac/mosfet??) - Or get a more stable power supply with good regulation.

A final thing might be more noise on the power line with the psu sending more current with the relay on. again a smoothing capacitor would help if this were the case.

You could also try looking into the wiring and see if the relay cables and the ds18b20 cables are far enough apart, some induction might be going on there between the cables. Also, make sure everything goes back to a single ground point. I can't imagine how an earth loop would cause what you describe, but it's always a good thing to do.....

Another thought to think about is matbe the magnetic field from the relap power cables are inducing into the sensor cables.

[ben999]

Hi
Can we talk about redundancy please? What if one or more sensor fail on a one-wire bus? Would it make the whole line unusable?
As part of a central heating MySensorization i would like to have groups of 3 sensors and have some sort of redundancy check.
Would i be allowed to run multiple one-wire busses on a single arduino?
Thanks a lot foryour help

[mfalkvidd]

@ben999 you can have as many onewire buses as you have digital pins. Just add more of these:

#define ONE_WIRE_BUS 3 // Pin where dallase sensor is connected 
OneWire oneWire(ONE_WIRE_BUS);

[ben999]

@mfalkvidd thanks a lot. Yes, that looks good to me. I will have a go.

The real big question now is about what happens when one or more sensor fails on the line.
I am not talking about removing a sensor, which doesn't produce any fault.
My concern is how does a DS18 ends its life under normal operation? Complete shortcut?

[mfalkvidd]

@ben999 I don't think there are any guarantees on how it will fail. If there are, the datasheet should list them.

[zboblamont]

@ben999 I cannot remember WHERE I read it, but if a DS18B20 fails it will either send impossible results when addressed or fail to be addressed at all as it is digitally addressed. Only cable short circuits can pull the entire chain down, as I found out when two socket pins had crossed over (sensor crimped into telephone plugs).

[ben999]

@mfalkvidd thank you for the idea. Had a look (boooooring reading for me ) but no mention to failiure

@zboblamont you're right. Seems that a faulty sensor return "85" (top of my head). And a "dead" sensor looses its bus address (next sensor on the chain takes its address and so on)

Thanks a lot gentlemen

[rejoe2]

@ben999 said in Temperature Sensor:

And a "dead" sensor looses its bus address (next sensor on the chain takes its address and so on)

That's not exactly right. Each of the 1-wire devices uses a hardcoded, unique address that can not be changed.
So if you use the standard sketch with multiple DS18B20, in case of detached or replaced sensors you may get reported the measured temperatures comming from the same physical DS18B20 device under a different ChildID (after node reboot). To avoid effects like that, one has to take additional measures as described here . In short:

• Use an array with the physical ID's to address them
• Store a hash-array (done automatically) to identify "known" physical ID's that have once been attached to the bus as well as the ChildID used for MySensors.

[ben999]

@rejoe2 oooooooooh great! thanks a lot, exactly what i was looking for !!!

[rejoe2]

@ben999 You are welcome

[pintman]

When I try to compile the sketch for an ESP8266 I get an error in DallasTemperature.h which results in an error in OneWire.h

OneWire.h:108:2: error: #error "Please define I/O register types here"  #error "Please define I/O register types here"

Is it possible to make the sensor run on an ESP?

[cashew75]

Hi, I'm having a hard time getting this Temperatursensor to work with Home Assistant. When i start it it doesn't register with the HA. If I use the same hardware and switch out the sensor to a DHT sensor (new sketch of course) then it works out of the box, HA sees the sensor. I've tried changing the Dallas DS18B20, but nothing. If i look at the logs the gateway have no problem with the sensor. Is there something in the code for the sensor that doesn't add up to it being presented to HA in the right way? I'm quite the newbie when it comes to programming.

[gohan]

Have you tried another controller like mycontroller?

[cashew75]

@gohan No I have not. I have a RF-Link also connected to the HA and it's working great. As I said, if I use the same hardware that I used to control the Dallas sensor and change the sensor to a DHT sensor the DHT sensor is accepted by HA and shows up as a sensor. That's why I was asking if there is something in the code for the Temperature sensor sketch that has to be changed to be able to present it to HA.

[gohan]

pls post the code that is not working

[cashew75]

@gohan Thanks for the quick reply! Well I've use the standard sketch for this Temperatur sensor. This is the code i've got.

// Enable debug prints to serial monitor
//#define MY_DEBUG 

// Enable and select radio type attached
#define MY_RADIO_NRF24
//#define MY_RADIO_RFM69

#include <SPI.h>
#include <MySensors.h>  
#include <DallasTemperature.h>
#include <OneWire.h>

#define COMPARE_TEMP 1 // Send temperature only if changed? 1 = Yes 0 = No

#define ONE_WIRE_BUS 3 // Pin where dallase sensor is connected 
#define MAX_ATTACHED_DS18B20 16
unsigned long SLEEP_TIME = 30000; // Sleep time between reads (in milliseconds)
OneWire oneWire(ONE_WIRE_BUS); // Setup a oneWire instance to communicate with any OneWire devices (not just Maxim/Dallas temperature ICs)
DallasTemperature sensors(&oneWire); // Pass the oneWire reference to Dallas Temperature. 
float lastTemperature[MAX_ATTACHED_DS18B20];
int numSensors=0;
bool receivedConfig = false;
bool metric = true;
// Initialize temperature message
MyMessage msg(0,V_TEMP);

void before()
{
  // Startup up the OneWire library
  sensors.begin();
}

void setup()  
{ 
  // requestTemperatures() will not block current thread
  sensors.setWaitForConversion(false);
}

void presentation() {
  // Send the sketch version information to the gateway and Controller
  sendSketchInfo("Temperature Sensor", "1.1");

  // Fetch the number of attached temperature sensors  
  numSensors = sensors.getDeviceCount();

  // Present all sensors to controller
  for (int i=0; i<numSensors && i<MAX_ATTACHED_DS18B20; i++) {   
     present(i, S_TEMP);
  }
}

void loop()     
{     
  // Fetch temperatures from Dallas sensors
  sensors.requestTemperatures();

  // query conversion time and sleep until conversion completed
  int16_t conversionTime = sensors.millisToWaitForConversion(sensors.getResolution());
  // sleep() call can be replaced by wait() call if node need to process incoming messages (or if node is repeater)
  sleep(conversionTime);

  // Read temperatures and send them to controller 
  for (int i=0; i<numSensors && i<MAX_ATTACHED_DS18B20; i++) {

    // Fetch and round temperature to one decimal
    float temperature = static_cast<float>(static_cast<int>((getControllerConfig().isMetric?sensors.getTempCByIndex(i):sensors.getTempFByIndex(i)) * 10.)) / 10.;

    // Only send data if temperature has changed and no error
    #if COMPARE_TEMP == 1
    if (lastTemperature[i] != temperature && temperature != -127.00 && temperature != 85.00) {
    #else
    if (temperature != -127.00 && temperature != 85.00) {
    #endif

      // Send in the new temperature
      send(msg.setSensor(i).set(temperature,1));
      // Save new temperatures for next compare
      lastTemperature[i]=temperature;
    }
  }
  sleep(SLEEP_TIME);
}```

[pepson]

Anybody has sketch for sensors dallas DS18b20 with identify it with ID Dallas ?
And i can change value 16 to more sensors ? Example 20 ?

[APL2017]

Looking at code example it seems to be sufficient to set bool metric = false to get readings in Fahrenheit, but node still returns readings in C. Any idea why?

[mfalkvidd]

@apl2017 if I'm looking at the same sketch as you are looking at, the metric variable is never used. getControllerConfig() is used to fetch the controller's metric setting instead.

[gniazdoj]

@Rene046
Hi guys

Hi
can you advice how to manage Domoticz to display 2 decimals under Temperature sensors page, when following line MsgTemp.set(temperature,2) I can see on arduino serial monitor, mysensors sent 20.75 value, the same value i can see under child item with Hardware tab but not on sensor where 20.75*C is rounded to 20.8. its fine for general log but i want to have stable temperature for heating system. I have added code to count average from last X records like 20 or 40 with 0.25 steps, this stabilize Heating system and protect it against on/off to frequently.
Additionally when i use JSON it will present proper value under sensor page, same with ESPEasy and 2 decimal configuration on ESP.
do you know how i can changed domoticz to force him to present 2 decimals?

Mysensors 2.3.1/2.3.2
Domoticz 4.10717
raspberry pi

Thank you
Jakub

[kimot]

Domoticz globally or only with MySensors ?
My Domoticz is the same version like yours.
Temperatures from ESPeasy are with two decimals on Temperature sensors page, but on devices page only one decimal.
Exactly the opposite like you wrote.

[gniazdoj]

@kimot
Hi
Thank you for feedback.
I have this issue only with mysensors. it's exactly like you wrote. Hardware tab, present 2 decimals ( for mysensors and espeasy). Device tab, present 1 decimal ( for all sensors), Temperature tab shows 2 decimal for esp easy and JSON updates but 1 decimal for mysensor. Not sure why.

Temporary I managed to workaround by using script taking data from Hardware page - child and sending JSON update all started by crone updating dummy sensor.

like this:

TEMP=`curl -s "http://X.X.X.X:XX/json.htm?type=command&param=mysensorsgetchilds&idx=40&nodeid=0"| awk 'NR>1{print $5}'| sed 's/"//g;s/^.//;s/)//g; s/,//g;/^$/d;s/]//g;' | sed -n '3,2p'`
IDX=255
curl -s "http://X.X.X.X:XX/json.htm?type=command&param=udevice&idx=$IDX&nvalue=0&svalue=$TEMP"

but for sure this can be workaround by dzVents and JSON handling results but i'm not skilled enough for that

Thank you
Jakub

[garubi]

The note before the example sketch states that you should use the "modified" library from MySensors examples.
But as of today, with MySensors 2.3.2 and Arduino 1.8.15 I used the standard DallasTemperature library (provided by the Arduino's Libraries manger) with no problems at all.

Using the "standard" Arduino libraries is a grate advantage, so I the custom library is no more used, it could be useful to update the guidelines in the page.

Stefano