Re: [PLUG] Does an Open Source Thermostat exist?
I used the RadioThermostat and a piece of software done by a fellow up in Canada. I just replaced the whole HVAC system with two compressor evaporator multi-zone mini-split systems so the Radio Thermostat is no longer of use to me. If you want it holler, the API is open as I understand it. The thermostat is model CT80, here is the Radio Thermostat URL https://www.radiothermostat.com/ This is the fellow that does the code for remote control of the thermostat. https://play.google.com/store/apps/details?id=mpp.android.thermostat=en_US=US There is a comment about not having a CT80. He now does, I ended up with two of them we were trying to iron out a couple of issues, the other thermostat was here doing nothing so I sent it to him. Just holler and I will get it going your way. It is coming off of the wall as the mini-split system has thermostats for each room, so it is just a wall decoration now. On Fri, Jul 15, 2022 at 11:48 PM TomasK wrote: > On Fri, 2022-07-15 at 18:07 -0700, Russell Senior wrote: > > On Fri, Jul 15, 2022 at 5:17 PM Tomas Kuchta > > wrote: > > > > > > On Fri, Jul 15, 2022, 17:04 Russell Senior > > > wrote: > > > > > > > I have used a bunch of these: > > > > > > > > https://www.amazon.com/gp/product/B00T0K8NXC/ > > > > and > > > > https://www.amazon.com/gp/product/B01G7BE9WK/ > > > > > > > > with https://github.com/merbanan/rtl_433 and an rtlsdr (like this: > > > > https://www.amazon.com/gp/product/B00VZ1AWQA/) to decode. > > > > > > > > For improved accuracy, I calibrated the sensors in an icebath (in > > > > several layers of ziplock bags and desiccant) for 0 degrees offset. > > > > . > > > > > > > > > These are good sensors with great battery life. I also have ThermPro > > > sensors, they work, but the ones Russell lists are better, smaller and > much > > > longer battery life. > > > > > > I do not calibrate them. I care about being comfortable and saving > power > > > rather than worry about whether the temperature reading is 0.2-0.3 > degrees > > > different from absolutely correct value. > > > > Fwiw, I didn't calibrate mine for a long time, but mine aren't so much > > for automated control, they were for understanding the temperature > > environments, and in particular differences and/or gradients in > > various microclimates. I noticed that a particular outside location > > seemed to get down to freezing before the other sensors. The > > significance of small temperature differences increases the closer you > > are to freezing, for example. Eventually, I just wanted to understand > > whether the difference was due to the sensor or the microenvironment > > it happened to be in. Unless vigorously stirred, there can be > > significant temperature differences over very short distances, due to > > heat sources, stratification, illumination, etc. > > > > I'd really like to have a lab grade temperature sensor, accurate to > > 0.01°C, to actually calibrate against. I encountered sensors when I > > worked in Oceanography with that kind of precision, but they were > > designed for water temperature and also were several thousand dollars. > > I wouldn't like to have one *that* much. Most consumer grade sensors > > only claim ±1°C. > > > > I was going to comment about - what atmospheric pressure did you calibrate > your > sensors at - then I had second thought thinking about relatively high > energy > needed/stored in H2O phase change which is connected to low dV (V-volume) > on the > opposite sides of liquid/solid phase. H2O is very interesting substance > indeed. > > Anyway, I checked the theory, so I would not fool myself with the other > smart > people here: > > This is because of the Clausius-Clapeyron equation > dlogT / dlogP = (P dV) / L > where T is the temperature of the phase transition, dV is the change in > volume, > and L is the latent heat. The water/gas transition has an enormous dV > because > gas is much less dense than water, so dT/dP is large. The water/ice > transition > has a dV about 10^-3, so dT/dP is small. > > There is some 'cost' L to be paid doing the phase transition, most of it > is paid > by thermal energy. If the volume changes during the transition, the P dV > work > can help lowering the necessary temperature. So, it makes sense that dT/dP > depends on the ratio of these two contributions. > > https://en.wikipedia.org/wiki/File:Phase_diagram_of_water.svg > > So, as a consequence - water boils at low temperature on Mt. Everest or in > space, but ice cream is about as difficult to make at low/high pressures > (unless > going above 1GPa+ (maybe there is a lot of ice(cream) in the middle of > sun/black-hole!) > > Happy weekend, it should be ideal for temperature observations (with > ice-cream) > -T > > -- Chuck Hast -- KP4DJT -- I can do all things through Christ which strengtheneth me. Ph 4:13 KJV Todo lo puedo en Cristo que me fortalece. Fil 4:13 RVR1960
Re: [PLUG] Does an Open Source Thermostat exist?
On Fri, 2022-07-15 at 18:07 -0700, Russell Senior wrote: > On Fri, Jul 15, 2022 at 5:17 PM Tomas Kuchta > wrote: > > > > On Fri, Jul 15, 2022, 17:04 Russell Senior > > wrote: > > > > > I have used a bunch of these: > > > > > > https://www.amazon.com/gp/product/B00T0K8NXC/ > > > and > > > https://www.amazon.com/gp/product/B01G7BE9WK/ > > > > > > with https://github.com/merbanan/rtl_433 and an rtlsdr (like this: > > > https://www.amazon.com/gp/product/B00VZ1AWQA/) to decode. > > > > > > For improved accuracy, I calibrated the sensors in an icebath (in > > > several layers of ziplock bags and desiccant) for 0 degrees offset. > > > . > > > > > > These are good sensors with great battery life. I also have ThermPro > > sensors, they work, but the ones Russell lists are better, smaller and much > > longer battery life. > > > > I do not calibrate them. I care about being comfortable and saving power > > rather than worry about whether the temperature reading is 0.2-0.3 degrees > > different from absolutely correct value. > > Fwiw, I didn't calibrate mine for a long time, but mine aren't so much > for automated control, they were for understanding the temperature > environments, and in particular differences and/or gradients in > various microclimates. I noticed that a particular outside location > seemed to get down to freezing before the other sensors. The > significance of small temperature differences increases the closer you > are to freezing, for example. Eventually, I just wanted to understand > whether the difference was due to the sensor or the microenvironment > it happened to be in. Unless vigorously stirred, there can be > significant temperature differences over very short distances, due to > heat sources, stratification, illumination, etc. > > I'd really like to have a lab grade temperature sensor, accurate to > 0.01°C, to actually calibrate against. I encountered sensors when I > worked in Oceanography with that kind of precision, but they were > designed for water temperature and also were several thousand dollars. > I wouldn't like to have one *that* much. Most consumer grade sensors > only claim ±1°C. > I was going to comment about - what atmospheric pressure did you calibrate your sensors at - then I had second thought thinking about relatively high energy needed/stored in H2O phase change which is connected to low dV (V-volume) on the opposite sides of liquid/solid phase. H2O is very interesting substance indeed. Anyway, I checked the theory, so I would not fool myself with the other smart people here: This is because of the Clausius-Clapeyron equation dlogT / dlogP = (P dV) / L where T is the temperature of the phase transition, dV is the change in volume, and L is the latent heat. The water/gas transition has an enormous dV because gas is much less dense than water, so dT/dP is large. The water/ice transition has a dV about 10^-3, so dT/dP is small. There is some 'cost' L to be paid doing the phase transition, most of it is paid by thermal energy. If the volume changes during the transition, the P dV work can help lowering the necessary temperature. So, it makes sense that dT/dP depends on the ratio of these two contributions. https://en.wikipedia.org/wiki/File:Phase_diagram_of_water.svg So, as a consequence - water boils at low temperature on Mt. Everest or in space, but ice cream is about as difficult to make at low/high pressures (unless going above 1GPa+ (maybe there is a lot of ice(cream) in the middle of sun/black-hole!) Happy weekend, it should be ideal for temperature observations (with ice-cream) -T
Re: [PLUG] Does an Open Source Thermostat exist?
I just checked. My zero offset's run from -0.7 to +0.5 °C, based on an hour-long fully-settled ice-bath zero-point calibration, over a sample of about 20 sensors. On Fri, Jul 15, 2022 at 6:07 PM Russell Senior wrote: > > On Fri, Jul 15, 2022 at 5:17 PM Tomas Kuchta > wrote: > > > > On Fri, Jul 15, 2022, 17:04 Russell Senior > > wrote: > > > > > I have used a bunch of these: > > > > > > https://www.amazon.com/gp/product/B00T0K8NXC/ > > > and > > > https://www.amazon.com/gp/product/B01G7BE9WK/ > > > > > > with https://github.com/merbanan/rtl_433 and an rtlsdr (like this: > > > https://www.amazon.com/gp/product/B00VZ1AWQA/) to decode. > > > > > > For improved accuracy, I calibrated the sensors in an icebath (in > > > several layers of ziplock bags and desiccant) for 0 degrees offset. > > > . > > > > > > These are good sensors with great battery life. I also have ThermPro > > sensors, they work, but the ones Russell lists are better, smaller and much > > longer battery life. > > > > I do not calibrate them. I care about being comfortable and saving power > > rather than worry about whether the temperature reading is 0.2-0.3 degrees > > different from absolutely correct value. > > Fwiw, I didn't calibrate mine for a long time, but mine aren't so much > for automated control, they were for understanding the temperature > environments, and in particular differences and/or gradients in > various microclimates. I noticed that a particular outside location > seemed to get down to freezing before the other sensors. The > significance of small temperature differences increases the closer you > are to freezing, for example. Eventually, I just wanted to understand > whether the difference was due to the sensor or the microenvironment > it happened to be in. Unless vigorously stirred, there can be > significant temperature differences over very short distances, due to > heat sources, stratification, illumination, etc. > > I'd really like to have a lab grade temperature sensor, accurate to > 0.01°C, to actually calibrate against. I encountered sensors when I > worked in Oceanography with that kind of precision, but they were > designed for water temperature and also were several thousand dollars. > I wouldn't like to have one *that* much. Most consumer grade sensors > only claim ±1°C. > > > > > -T
Re: [PLUG] Does an Open Source Thermostat exist?
On Fri, Jul 15, 2022 at 5:17 PM Tomas Kuchta wrote: > > On Fri, Jul 15, 2022, 17:04 Russell Senior > wrote: > > > I have used a bunch of these: > > > > https://www.amazon.com/gp/product/B00T0K8NXC/ > > and > > https://www.amazon.com/gp/product/B01G7BE9WK/ > > > > with https://github.com/merbanan/rtl_433 and an rtlsdr (like this: > > https://www.amazon.com/gp/product/B00VZ1AWQA/) to decode. > > > > For improved accuracy, I calibrated the sensors in an icebath (in > > several layers of ziplock bags and desiccant) for 0 degrees offset. > > . > > > These are good sensors with great battery life. I also have ThermPro > sensors, they work, but the ones Russell lists are better, smaller and much > longer battery life. > > I do not calibrate them. I care about being comfortable and saving power > rather than worry about whether the temperature reading is 0.2-0.3 degrees > different from absolutely correct value. Fwiw, I didn't calibrate mine for a long time, but mine aren't so much for automated control, they were for understanding the temperature environments, and in particular differences and/or gradients in various microclimates. I noticed that a particular outside location seemed to get down to freezing before the other sensors. The significance of small temperature differences increases the closer you are to freezing, for example. Eventually, I just wanted to understand whether the difference was due to the sensor or the microenvironment it happened to be in. Unless vigorously stirred, there can be significant temperature differences over very short distances, due to heat sources, stratification, illumination, etc. I'd really like to have a lab grade temperature sensor, accurate to 0.01°C, to actually calibrate against. I encountered sensors when I worked in Oceanography with that kind of precision, but they were designed for water temperature and also were several thousand dollars. I wouldn't like to have one *that* much. Most consumer grade sensors only claim ±1°C. > > -T
Re: [PLUG] Does an Open Source Thermostat exist?
The things you listed sound a lot like a full home automation, even if it is just controlling the thermostat. All the sensors needed to detect presence, time, temperature, etc. can be done "simply" using something like Home Assistant (https://www.home-assistant.io/) and no cloud or even internet required for many configurations. There are many people that have built Open Source thermostats that tie into their systems and will control multiple zones based on presence, weather forecast, time of day, etc. Beware, this is a deep rabbit hole, proceed with caution. On Fri, Jul 15, 2022 at 5:17 PM Tomas Kuchta wrote: > On Fri, Jul 15, 2022, 17:04 Russell Senior > wrote: > > > I have used a bunch of these: > > > > https://www.amazon.com/gp/product/B00T0K8NXC/ > > and > > https://www.amazon.com/gp/product/B01G7BE9WK/ > > > > with https://github.com/merbanan/rtl_433 and an rtlsdr (like this: > > https://www.amazon.com/gp/product/B00VZ1AWQA/) to decode. > > > > For improved accuracy, I calibrated the sensors in an icebath (in > > several layers of ziplock bags and desiccant) for 0 degrees offset. > > . > > > These are good sensors with great battery life. I also have ThermPro > sensors, they work, but the ones Russell lists are better, smaller and much > longer battery life. > > I do not calibrate them. I care about being comfortable and saving power > rather than worry about whether the temperature reading is 0.2-0.3 degrees > different from absolutely correct value. > > -T >
Re: [PLUG] Does an Open Source Thermostat exist?
On Fri, Jul 15, 2022, 17:04 Russell Senior wrote: > I have used a bunch of these: > > https://www.amazon.com/gp/product/B00T0K8NXC/ > and > https://www.amazon.com/gp/product/B01G7BE9WK/ > > with https://github.com/merbanan/rtl_433 and an rtlsdr (like this: > https://www.amazon.com/gp/product/B00VZ1AWQA/) to decode. > > For improved accuracy, I calibrated the sensors in an icebath (in > several layers of ziplock bags and desiccant) for 0 degrees offset. > . These are good sensors with great battery life. I also have ThermPro sensors, they work, but the ones Russell lists are better, smaller and much longer battery life. I do not calibrate them. I care about being comfortable and saving power rather than worry about whether the temperature reading is 0.2-0.3 degrees different from absolutely correct value. -T
Re: [PLUG] Does an Open Source Thermostat exist?
I have used a bunch of these: https://www.amazon.com/gp/product/B00T0K8NXC/ and https://www.amazon.com/gp/product/B01G7BE9WK/ with https://github.com/merbanan/rtl_433 and an rtlsdr (like this: https://www.amazon.com/gp/product/B00VZ1AWQA/) to decode. For improved accuracy, I calibrated the sensors in an icebath (in several layers of ziplock bags and desiccant) for 0 degrees offset. On Fri, Jul 15, 2022 at 1:24 PM Larry Brigman wrote: > > On Thu, Jul 14, 2022 at 2:53 PM Tomas Kuchta > wrote: > > I have seeded house + exterior with bunch of 433MHz wireless temperature + > > humidity sensors - which I read with cheap SDR. > > I control this with simple raspberry PI + relay board + simple program. > > Which sensors did you used?
Re: [PLUG] Does an Open Source Thermostat exist?
On Thu, Jul 14, 2022 at 2:53 PM Tomas Kuchta wrote: > I have seeded house + exterior with bunch of 433MHz wireless temperature + > humidity sensors - which I read with cheap SDR. > I control this with simple raspberry PI + relay board + simple program. Which sensors did you used?
Re: [PLUG] Does an Open Source Thermostat exist?
There are plenty of projects out there for thermostats. Here is one that I found using "DIY Nest thermostat" https://www.stuff.tv/features/how-build-homemade-nest-thermostat/ On Thu, Jul 14, 2022 at 2:22 PM Paul Heinlein wrote: > On Thu, 14 Jul 2022, Frank Filz wrote: > > > Program a single preferred temperature (the thermostat won't let us > > set heat to and cool to temperatures closer than 3 degrees - I > > understand that is necessary to keep the system from over heating so > > it has to turn on air conditioning only to over cool, and turn heat > > back on.). With programing I could have it not turn on cooling if > > the temperature is slightly high IF the system had just been heating > > and visa versa. > > In the grand PLUG tradition of not really answering your question, > I'll note that my Nest thermostat has "heat only" and "cool only" > modes in addition to "heat/cool". > > In "heat only" mode, the AC never kicks in regardless of how hot it is > in the house -- and vice-versa for "cool only" mode. > > I find those modes much more predictable and energy-efficient than the > combined "heat/cool" mode. > > I know Nest is a commerical product and that there are privacy > concerns. I'm just reporting my experience. > > -- > Paul Heinlein > heinl...@madboa.com > 45°22'48" N, 122°35'36" W >
Re: [PLUG] Does an Open Source Thermostat exist?
On Thu, 14 Jul 2022, Frank Filz wrote: Program a single preferred temperature (the thermostat won't let us set heat to and cool to temperatures closer than 3 degrees - I understand that is necessary to keep the system from over heating so it has to turn on air conditioning only to over cool, and turn heat back on.). With programing I could have it not turn on cooling if the temperature is slightly high IF the system had just been heating and visa versa. In the grand PLUG tradition of not really answering your question, I'll note that my Nest thermostat has "heat only" and "cool only" modes in addition to "heat/cool". In "heat only" mode, the AC never kicks in regardless of how hot it is in the house -- and vice-versa for "cool only" mode. I find those modes much more predictable and energy-efficient than the combined "heat/cool" mode. I know Nest is a commerical product and that there are privacy concerns. I'm just reporting my experience. -- Paul Heinlein heinl...@madboa.com 45°22'48" N, 122°35'36" W
