Beta version of virtual temperature feature

[visualapproach]

Development branch - 2022-07-10

Hi community! Thought I'd say something about the latest update.
Often when stopping the pump and it's cold outside, the temp shown is lower than the actual temperature of the water body. This is due to the thermometer is located in the pump which cools down much quicker than the main water body. Now there is a virtual temperature, where the ESP tries to estimate the actual temperature, assuming it moves towards the ambient temperature. The virtual temp is corrected only when the pump is running and a new temp is reached by the real thermometer.
The table is self adjusting when pump is running with no heating.
There is default values that should be in the right ballpark, but to calibrate - Heat up to your preferred ready-temp (38-ish C). Then turn off the heater but keep the pump going. Every temperature change on the way towards ambient temperature, it will adjust and save the cooling rate. So next time it will be quite accurate. Or at least that's the goal. Since we now have a higher resolution thermometer, that takes the ambient temperature into account, we can make a better estimate of how long it will take to reach target temp. The old method "time to target temp" is still there in addition to this "time to ready".
I don't have any tub to test it on for the moment, so you are welcome to try it out and give feedback here.
By the way - I also made three channels of temperature to web sockets and mqtt - Celsius, Farenheit and whatever the pump is set to. HA sensors should now not be so confused about the unit. You may have to remove the old device in HA and restart.
I updated the YAML examples with an example to get HA to update the ambient temperature to the ESP.

[chunkysteveo]

Worth noting (not sure what/how you're doing the maths?!) that the difference can go the other way - for me, when the pump is off, and the Sun is out, the temp read by the unit is WAY higher than the water temperature, like a "greenhouse effect" I think? The sensor in the tubes gets hotter, and turning on the pump flushes out the static water and the temperature value drops to the actual water temp.

Not sure if that's helpful??

Would be good also to have some pre-built code with a flag to enable/disable an external temperature probe, and to hook up to one of the spare pins on the PCB, either a Dallas probe or a DHT11/22 sensor. People can choose if that's an external temp, case internal temp, throw it in the water extra temp, etc. Default disabled as most won't have or want that extra sensor.

[visualapproach]

Thank you! The temperature readings is discarded when the pump is off so it shouldn't matter if it hotter or colder. When pump is off it ticks at a certain rate towards the ambient temperature. The rate is increasing the further away from ambient you are. Saved in file "coolarray.json".
But it's great with these comments so I can handle situations I haven't thought of.

[visualapproach]

And one more thing. I tried to connect a temp probe (Dallas) to D0/D8 but it's a no go for different reasons. Maybe if we move the audio pin but not sure.

[Bishbosh02]

I added this to my system value_template: "{{ value_json.VTM | round(2)}}" as only want the temp to 2 decimal places, also I had a blip when the pump started and I turned the heater on

[Bishbosh02]

One thing I found with the old version if you re-boot when you have an error (only way to clear the error) the unit setting changed to F so yes I think its best to wait after a re-boot before sending MQT info, I have just loaded the last dev vision 2022-07-16 and the readings look OK so-far....

[visualapproach]

Yes i'll fix the start up behavior.

[Bishbosh02]

[visualapproach]

@Bishbosh02 weird. Can you add VTF sensor and AMB and zoom in the area from pump goes on? If you want.

[Bishbosh02]

[visualapproach]

Thank you. Can you verify that you had the 2022-07-16 version installed? I can't see why it should behave like that. It doesn't in my setup. Anyhow, I tweaked things a little again. Latest code 2022-07-19. I suggest you go to the web ui menu. Choose remove file. Enter coolarray.json and delete it. It will be created again with default values. It probably had some stupid values in it from the previous code.

[Bishbosh02]

Yes I was running 2022-07-16 and I have updated to 2022-07-19 and it looks good

[Bishbosh02]

I updated the code at 11:00 and the VT temp is just going up where spa temp and hot tub temp are constant (its a very hot day in the UK today 39deg C ) VT temp appears to try and track ambient when the pump is running ?

[visualapproach]

Yes, VT will go towards AMB at a rate saved in coolarray.json file. It stores 20 values- one for each degree off from ambient. So if your coolarray has too high numbers in it, it will go faster towards ambient than actual temperature does. Or if your tub is heavily insulated it will of course have a lower rate of change than the ESP thinks. Until it’s calibrated. Calibration is done when 1) pump is on and has been on for at least 5 min. 2) actual temp is changing a degree and no one messed with heater or bubbles, which would affect the rate we want to measure. 3) heater is off.
So, when hot tub temp raises one degree next time the VT will align to that and calculate the rate 1degree in x hours at this particular offset from ambient. And tomorrow the line will follow much closer, if all other things are the same, like difference between hot tub temp and ambient.

If you spot stupid behavior again you are welcome to tell me. Thx for your report

[visualapproach]

Yes, VT will go towards AMB at a rate saved in coolarray.json file. It stores 20 values- one for each degree off from ambient. So if your coolarray has too high numbers in it, it will go faster towards ambient than actual temperature does. Or if your tub is heavily insulated it will of course have a lower rate of change than the ESP thinks. Until it’s calibrated. Calibration is done when 1) pump is on and has been on for at least 5 min. 2) actual temp is changing a degree and no one messed with heater or bubbles, which would affect the rate we want to measure. 3) heater is off. So, when hot tub temp raises one degree next time the VT will align to that and calculate the rate 1degree in x hours at this particular offset from ambient. And tomorrow the line will follow much closer, if all other things are the same, like difference between hot tub temp and ambient. If you spot stupid behavior again you are welcome to tell me. Thx for your report Hämta Outlook för iOS<https://aka.ms/o0ukef>

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________________________________ Från: Bishbosh02 ***@***.***> Skickat: Tuesday, July 19, 2022 6:23:12 PM Till: visualapproach/WiFi-remote-for-Bestway-Lay-Z-SPA ***@***.***> Kopia: visualapproach ***@***.***>; Author ***@***.***> Ämne: Re: [visualapproach/WiFi-remote-for-Bestway-Lay-Z-SPA] Beta version of virtual temperature feature (Discussion #328) I updated the code at 11:00 and the VT temp is just going up where spa temp and hot tub temp are constant (its a very hot day in the UK today 39deg C ) VT temp appears to try and track ambient when the pump is running ? [VtempBlip9]<https://nam12.safelinks.protection.outlook.com/?url=https%3A%2F%2Fuser-images.githubusercontent.com%2F9953147%2F179800019-d0b56441-9635-4edb-9b9d-5250f430ce5e.JPG&data=05%7C01%7C%7C425349414cbf4fdf6c9508da69a301af%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C637938446082870814%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&sdata=DsfTaqj%2F%2BbbRa4ah4I8VVX6C%2FCu2cA6w5x64EPu%2F6HY%3D&reserved=0> — Reply to this email directly, view it on GitHub<https://nam12.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgithub.com%2Fvisualapproach%2FWiFi-remote-for-Bestway-Lay-Z-SPA%2Fdiscussions%2F328%23discussioncomment-3182234&data=05%7C01%7C%7C425349414cbf4fdf6c9508da69a301af%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C637938446082870814%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&sdata=3FMJeXngTupQqf3h34NhS3xpqLjX4yDQ5G%2BzIjGJqKc%3D&reserved=0>, or unsubscribe<https://nam12.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgithub.com%2Fnotifications%2Funsubscribe-auth%2FAFPMD4RIE4BCRFNSJEQINDDVU3I7BANCNFSM53FQ6ZKQ&data=05%7C01%7C%7C425349414cbf4fdf6c9508da69a301af%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C637938446082870814%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&sdata=ejveHUdqfe%2Frfyv1r5CIczSbxD1UJ6Zfq3gsHDNSh3g%3D&reserved=0>. You are receiving this because you authored the thread.Message ID: ***@***.***>

[Bishbosh02]

OK thanks for the information I had just assumed that if the pump is running (VT temp = Measured Temp) and you only started using ambient temp to calculate VT temp when the pump was off

[visualapproach]

Yes that's a matter of choice. I chose to not follow the constant temperature because I thought it would be better to have fractional degrees. Good if it's good at estimating, otherwise not so good.

[GSzabados]

Any chance that ambient temperature can be update though MQTT or any other form, but not from the Web interface's slider?

[Skeletorjus]

This is possible, see this example:
https://github.com/visualapproach/WiFi-remote-for-Bestway-Lay-Z-SPA/blob/master/Code/Home%20assistant%20config/update%20ambient%20temp%20automation%20snippet.yaml

[GSzabados]

Thanks! I haven't looked at that yet. Thanks for the pointer!

[GSzabados]

@Skeletorjus, thanks again! The Automation works well.

And here is a shout out to @visualapproach. The virtual temperature is top notch!

[visualapproach]

Nice!

[visualapproach]

Development version moved to MASTER.
Development now includes a beta version of virtual temp for 4 wire systems. To calibrate, keep pump on, heater off until it has cooled to at least 2 C below setpoint. And don't use bubbles/jets while calibrating. Thx

[cobaltfish]

so I ran the pump for 1 hour first thing, then stopped it, and it didn't work right:

To try and help with debugging, I've added a new mqtt output for /sensor/layzspa_4w_virtualtemp_r/config in main.cpp:
doc["dev"] = devicedoc["dev"]; payload = ""; topic = String(HA_PREFIX) + F("/sensor/layzspa_4w_virtualtemp_r/config"); Serial.println(topic); doc["name"] = F("Layzspa virtual R"); doc["uniq_id"] = "sensor.layzspa_4w_virtual_temp_R"+mychipid; doc["stat_t"] = mqttBaseTopic+F("/message"); doc["val_tpl"] = F("{{ value_json.R | round(10) }}"); doc["exp_aft"] = 700; doc["avty_t"] = mqttBaseTopic+F("/Status"); doc["pl_avail"] = F("Alive"); doc["pl_not_avail"] = F("Dead"); if (serializeJson(doc, payload) == 0) { Serial.println(F("Failed to serialize HA message!")); return; } mqttClient.publish(topic.c_str(), payload.c_str(), true); mqttClient.loop(); Serial.println(payload); doc.clear(); doc.garbageCollect();
and added
doc["R"] = R_COOLING; in BWC_8266_4w.cpp in the tring BWC::getJSONStates() section.

If I've understood the code right, that should pull the current / latest value, rather than the one in settings.txt

[visualapproach]

Yes that's right, the R-value is loaded at startup and then updated continuously when the states are right.
I don't think 1 hour is enough, you need to keep the pump on and nothing else until it registers a complete period, say from 37 to 35 degrees. It can then measure how long it took from switching to 36 to switching to 35.

[cobaltfish]

heh, I thought to myself just after I posted "perhaps I should have left it running longer"
Patience is a virtue!
I started the pump at 10 am, at about 11, it dropped 1c, and calculated R =37
At about 13:50, it dropped to 33 and recalculated R = 57

Just as I started to post this and get screen grabs at about 14:30, the wifi dropped out, the controller got upset, rebooted, and loaded 37 from the settings.txt. But it was working :-)

[visualapproach]

Nice, Thank you for testing. I'll add checks for other events now that I know it works.

[visualapproach]

The VT should be on par with the 6 wire version now.

[hubaksis]

Interesting approach.

I have a workaround that already works for almost a year.
My spa is connected to OpenHab via MQTT.
I have two items: actual temperature and display temperature.
Every 30 minutes OpenHab requests actual temperature by turning on the pump for 1 or 2 minutes and then reads the temperature. This is the accurate water temperature.

So, if you want to get the actual temperature for any adjustments/checks, maybe it's possible to add an option to save the temperature only if the pump is on (and for example turn on the pump for 2 minutes every half an hour)?

Cheers.

[visualapproach]

Yes, running the pump is the only way to get a good measurement, and scheduling it as you mention is a great way. The virtual temp is filling in the gaps by estimating the temp to fractions of a degree when there is no trustworthy measurements available. Of course the error will increase over time so running the pump every now and then will correct that. In this code the pump must run for 5 min before the measurement is trusted and therefore used to update the virtual temperature.
Cheers