The problem I try to solve Looking for a temperature sensor using Bluetooth that can report to Home Assistant through my phone when out and about and preferably (but not necessarily) report through my ESPhome BT-proxies at home.
Background I have a 3 year old son with type 1 diabetes. As a result I always have to carry insulin, a temperature sensitive medication. The vials are stored long term in the door of my fridge together with a ZigBee sensor monitoring the temperature of the insulin. If it freezes the Insulin denatures and won’t have any relevant effect if used. The vial that I carry with me will last for around a month as long as it stays above 0 °C (and under around 25-30 °C). My son uses a CGM/pump-based system, creating a BAN that also involves his smartphone. This means that phone is always near the vial and could record temperature (and send telemetry data) continuously, even away from home. I want to use a temperature sensor to identify spoiled medication due to thermal conditions even when my son leaves our home.
My current (imperfect) solution I currently deploy a solution where I use a Meshtastic node with a BME280 sensor. It reports through the mesh to a node at home. This node uses MQTT to talk to Home Assistant. The problem with this system (although nice being totally independent from the Internet) is limited coverage of the surroundings as well as very infrequent telemetry reporting to not overload the common mesh in my city.
Is there an easier solution? Preferably one that uses the smartphones bluetooth (BLE?) and reports back over the Internet.
For a low tech solution, you could use cold chain labels.
They indicate when a temperature threshold is breached. So you’d at least know when a vial was spoiled. They’re not cheap, mind, when you only want a few.But I know that’s not solving the problem in the way you wanted to!
If you only need to know when a threshold is exceeded, you could make something simple using (for example) an esp with a PAYG SIM card and a temperature sensor.
Then set it up to SMS an alert when temperatures go out of bounds. And pick the SMS up in HASS (various ways). That way, you’ll only be spending a few cents each time there is an issue.
You could also use mobile data if you felt more fancy, and post straight to HASS.
I have Type 1 Diabetes, and I’m always looking for fun/interesting ways to help me manage it, including some Home Assistant tools, like the Nightscout integration.
If your son is using an insulin pump, why are you taking a vial of insulin with you day-to-day? Even small pumps like the omnipod hold much more than one day’s worth.
When I do need to bring vials of insulin with me (if I’m camping in the summer for more than a few days, for instance), I just use a Frio pouch. They’re little evaporative coolers that keep the insulin cold enough. I’m sorry for ignoring your question, but it sounds like you could be making things more difficult for yourself than you have to.
Hi and thanks for the imput. I’ve already found nightscout/xdrip and delved into creating a monitoring system for my son to use in the future.
The spare insulin is not really for filling pump reaervoirs, but rather in case of pump malfunction. In Sweden T1D:s always carry spare insulin together with manual injectors.
The concern is primarily low temperatures and frozen insulin when me and my wife work and my son is in kindergarten.
I know this is technically not an answer to your question, but as a fellow T1 diabetic (for 20+ years) and dad to diabetic child (currently 2½ years old): Is this something that regularly happens to you? I don’t know where you live, but in over 20 years of being a T1 diabetic I never had a vial of regular insulin go bad. I don’t have to worry about the cost of insulin as my insurance would without any questions replace any medications gone bad for me, but I understand that this is a luxury not everyone shares.
There are products (but I have to assume you are aware of this) that can help you with the temperature safe transport of insulin for everyday use (basically insulated pouches with an integrated cooling pad). That may be something you can look into if this is something you need to worry about.
Thanks for the answer! I’ve yet to experience ruined insulin due to thermal conditions. My son recently debuted but will soon go back to kindergarten and they will need to handle the medication during the day. Both me and my wife are medical doctors but the staff at kindergarten are not well experienced with medicine and may accidentally leave it outside for too long.
In Sweden where I live the medication and equipment is free so that’s not the reason to watch the temperature. Looking outside my window right now there’s snow everywhere and -19 °C. In the maternal line of my son T1D is common and frozen insulin is not too uncommon, heat damage not a problem.
I realize this is not of great concert but I’d like the challenge of creating a monitoring system.
I totally understand your concerns. We just don’t have such cold winters here in Germany. And I also understand your point more (also after having read your other comments). If the insulin vial in question is a spare it will most likely not being noticed if it freezes until it is needed.
In theory you could use the Bluetooth sensors of the companion app which can be used to detect BLE beacons. But that would require a special Bluetooth device that activates once a threshold temperature has been detected. Maybe such things exist (I’m thinking of (food) supply chain monitoring), but I am not aware of any.
It’s always hard to describe the use case in enough detail without being so boring that other people will read to the end ;)
Didn’t know about the companion app being able to detect BLE beacons. I have never heard about a beavon coming to life if outside set twmperature range. If such a product were to exist it would be great.
have a look at the Shelly H&T (and the new G3 version). They are cost effective battery or mains powered temperature sensors that include both bluetooth and wifi. They work locally with no hub required but can also report to the cloud where alerting can be configured.
Nice unit! As per the specifications it operates in the interval 0-40 °C only though. A bit to narrow for my use case but maybe it will work outside that range too? I have some Shelly relays in my walls and a some plugs but no mobile units. Can it be used away from home and report back home?
I don’t know much about it but it seems Theeng could help?
I think this would work! Maybe I won’t be able to have the same entity for the MQTT entity and the measurements captured via the Bluetooth proxies at home though. Many thanks
There are some Xiaomi Bluetooth temperature sensors available. I have a few of the LYWSD03MMC models. They are very cheap, have a LCD screen, and can also be flashed with custom firmware.
I have a few flashed with custom firmware and use them as general sensors around the home integrated with Home Assistant via ESPhome proxies.
I’m not sure how you could monitor them from both a phone and a Bluetooth proxy, but as they are so cheap and hackable they might be worth playing with.
I use the same sensor but flashed to use ZigBee. I have loads of them at home and they work great.
I think I will buy some more and use them with Bluetooth along with https://github.com/theengs/app
Possibly a Sensorpush would work. They also have a WiFi gateway so it can send data even when a phone is out of BLE range.
