My sensor is built to run with DC power with battery backup in the case of power outage. The sensor function as repeater also which require the radio to be on all the time. It is not designed to be used exclusively with battery. The sensor reading should be as accurate in DC powered and well as in battery power.
It can use any JST PH2.0 LIPO/LI-on 1S battery. These kind of battery is know as RC (remote control toys) battery. There are other options in Amazon. For example,
Please make sure you check the polarity. RC LIPO battery may not be standardized the polarity. Some vendor flip the around. But, JST PH2.0 can be reconfigured easily.
There is no programming needed on the board. I have my custom DTH. You do not need to write your own. But, you can if you want to. It exposes standard Zigbee clusters. That is all you need to get Light, Temperature,Humidity and pressure measurement. The sensor can do more. It has plenty of expansion possibility. I will be happy to elaborate more if you are looking to do DIY work on it.
Got it. Sure, you may want to consider some of the battery powered Humidity and Temperature sensor. Xiaomi make one. But, they are tricky to use. There are other sensor as well that probably suite your need.
If you need repeater for those sensor since they will be encapsulated in the box, you can go back and consider mine. My sensor work as repeater as well with dedicated power amplifier. This will help penetrate hard to pass enclosure. It will help with those hard to work Xiaomi sensors as well for different reason.
Received the sensor today, Got it up and running immediately! I now can do some routines to turn off our dehumidifier since it typically returns humidity levels at least 10% points too high. I have a analog temp/humidity sensor that I can see the humidity sensor you sent me and the analog are pretty close in measurement, whereas the dehumidifier is way too high. Thanks so much for this product!
I have not try the DeConz/Conbee. I have a feeling that It should work. There was a community member that uses similar setup to pair with my sensor. You may want to reach out to one of the individual in the thread.
Anyway, your timing is so impeccable. I just tested the sensor with home-assistant + zigbee2mqtt. So far it work fine in this setting. But, this is just something that I got running for a day or so.
At this point, there is a couple way to support external probe.
The first one is using an analog input with K-type probe thermocouple. You need to have a module that take k-type thermocouple to the analog input. Please do shop around for AD8495. There should be better price for it. I just give you an example.
You need the K-Type probe itself.
I have the DTH for this. I can find it for you.
Today, the sensor support serial expansion. If you are open to do Arduino coding, there are a few more option. You can use probe like below.
This probe can be found at much much more lower cost. You can use a cheap arduino Uno or STM32 to interface this probe and send the data to the hub through the Environment sensor. These MCUs can be had for less than $5. The Environment Sensor would act as serial tunnel. It is kind of a replacement to ThingShields.
I brought these options to answer @douglaspitman questions. However, I am also interested to learn if anyone else would need something like an external probe. If there are enough need, I am considering to find the ideal solution and prepackage them into ready to use solution rather than a DIY.
I’m not a programmer so your option 1 is what I would consider. I bought one of your devices a few weeks ago for the repeater function. It’s helped my Zigbee network, so I bought another one today to get better coverage on the other side of my house (in the garage). I have been looking at ways of monitoring my freezer and believe just a probe into the freezer would be my best option… so I recalled you had something rigged up a few years ago… I can knock off two use cases for just a little more money. What is your opinion on this probe with the AD8495?
That would work. Any K-Type probe should work with AD.
I personally would find something cheaper K-Type probe. I got some probe that look like just a cable. They work just fine. Please consider the braided cable thickness. It is premium feature. But, if it cause your freezer not closing properly, may be a cheaper cable K-probe is easier to route eventually.
In the ST community there is a project using this type of sensor to a device with an external probe option. He drilled a hole and used a rubber grommet to eat it. Looked good so I thought I’d go that route. You might want to post you level of interest in that string, it sounds like a popular use case.
AD8495 can be fitted by configurable reference voltage. I found a hard lesson that some vendor may have different refernce value. Once you got the board, we can try some experiment to find out.
You can power AD8495 from 5V or 3.3v. If you power it from 5V you may need to have voltage divider. The code currently assume that you will be powering from voltage divider. The reason for voltage divider is that using 5V, you can measure higher temperature. But, the MCU is can only measure up to 3.3V. The voltage divider will divide the output voltage to make it lower. The code above use 1/2 voltage divider. If you go this route, the ideal resistor value is 10k.
You just need not to multiple the voltage calculation by 2. Using 3.3V as power to AD8495 will simplify the wiring. It is just support less temperature range. Based on what you mentioned, you are not trying to measure extreme heat, I do not see that you need higher voltage. AD8495 can be powered up to ~18v for higher temperature support.
I have realized that since the Serial port feature has been introduced, I have do not have any example on how to use it.
Thanks to @douglaspitman for bringing up the topic, I write an Arduino sketch that read DS18B20 sensor and send the data through the Environment sensor.
I use a board named blue pill. It is based on STM32. Arduino has support for this board. I go with Arduino route since it is really easy to write the code that pull data from DS18B20 and send it over through the serial port. Arduino has so many library so that we can write simple code quickly.
I will upload the code on Arduino and DTH. I will avoid the detail instruction on this thread to keep it short. But, if you need more information, please do feel free to reach out. I will be happy to document them.
This is the rough image how all the component put together for testing. I am also testing how long I can wire the probe. I am able to get the wiring roughly around 15 feet. I use CAT-5 cable. I have suspicion that I can go much longer than 15 feet. I do not have cable longer than that. I am looking to get 100 feet cable to test if possible.
You can get DS18B20 sensor for less than $3, if you are not afraid of looking to the Chinese supplier. The blue pill boards can be purchased for less than $3. For total of less than $6, you can extend the sensor to include the probe. Here is the kicker, this is not the end of what you can do. If you notice the Arduino board above, we only use small number of pin in the board. There are plenty of other sensor that you can connect to the Arduino and expose it to the ST hub.
If you have something in mind to connect, please feel free to reach out.