Mini Weather Station
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If you at some point redesign the nice looking weather station, I recommend:
1)To place the battery in the top, to avoid battery corrosion
2) Make a little hole in bottom for water condensation trip out hole -
The pro minis have an onboard voltage regulator (raw input). The specs say that they are good for up to 12v for either the 5v or 3.3v version. I used a 3.3v version as it made the rest of the interface easier.
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I am curious what kind of battery life you are getting with the 9 volt battery? I tried a sensor with a 9 volt battery and the useful battery duration was less than ideal.
Vera Plus running UI7 with MySensors, Sonoffs and 1-Wire devices
Visit my website for more Bits, Bytes and Ramblings from me: http://dan.bemowski.info/ -
I am curious what kind of battery life you are getting with the 9 volt battery? I tried a sensor with a 9 volt battery and the useful battery duration was less than ideal.
@dbemowsk said in Mini Weather Station:
I am curious what kind of battery life you are getting with the 9 volt battery? I tried a sensor with a 9 volt battery and the useful battery duration was less than ideal.
Typical capacity is around 550mAh for alcaline version. All extra voltage is wasted in the linear regulator so you end up with less than half the capacity of 2 AAA or about 20% of the capacity of 2 AA. Not a good choice imho, better switch to i2c sensors like si7021 or BME280 like MikeF did to have much lower power consumption and much lower voltage requirements and use 2 AAA. And the lower the voltage is, the lower the current consumption is for Arduino, radio and sensor so in the end instead of having 4 months of battery life you can get 2 or 3 years with 2 AAA.
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I had tried a 9 volt when I was building my temp/humidity sensor node and the battery didn't last for crap. At that time I was using a DHT22 with a 5 volt pro mini. I have since switched to an HDC1080 and a 3.3 volt pro mini with 2 AA batteries and it works GREAT. Here is the project if anyone wants to look.
https://forum.mysensors.org/topic/6485/hdc1080-battery-operated-temp-humidity-sensor-with-wall-box -
I am curious what kind of battery life you are getting with the 9 volt battery? I tried a sensor with a 9 volt battery and the useful battery duration was less than ideal.
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@jtm312 I don't recall exactly how much I was getting on mine, but I don't think it was that much. Are you using 3.3 or 5 volt pro minis?
@dbemowsk I am using the 3.3V pro minis. It is the one pictured at the top of this thread. I started out by getting about a week. The big difference came after removing the LEDs, as they were using most of the power. Also sleeping most of the time.
A good quality 9v also helped. Other humidity sensors can also cut the power drain.
I have also built version using 2xAAA batteries, but I find that it doesn't take long before the voltages drops below the useful voltage for the radio and starts to cause a range problem. The next version I am planning on going back to using the onboard regulator with 4xAA batteries.
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@dbemowsk I am using the 3.3V pro minis. It is the one pictured at the top of this thread. I started out by getting about a week. The big difference came after removing the LEDs, as they were using most of the power. Also sleeping most of the time.
A good quality 9v also helped. Other humidity sensors can also cut the power drain.
I have also built version using 2xAAA batteries, but I find that it doesn't take long before the voltages drops below the useful voltage for the radio and starts to cause a range problem. The next version I am planning on going back to using the onboard regulator with 4xAA batteries.
@jtm312 I am using 2 AA's on my humidity sensor and that is working very well. The radios are rated I believe down to 1.9 volts. Using the regulator is going to give you more power drain on your batteries. When using 2 AA batteries, there is no need for the regulator at all. Many people say to disconnect it because it can still cause power drain. In my project I just didn't connect to the RAW pin, thus the regulator is not being used. So far I have not seen any issues with the regulator affecting anything.
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@jtm312 I am using 2 AA's on my humidity sensor and that is working very well. The radios are rated I believe down to 1.9 volts. Using the regulator is going to give you more power drain on your batteries. When using 2 AA batteries, there is no need for the regulator at all. Many people say to disconnect it because it can still cause power drain. In my project I just didn't connect to the RAW pin, thus the regulator is not being used. So far I have not seen any issues with the regulator affecting anything.
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Yes NRF24 can run down to 1.9V. ATMega328 on the Arduino down to 2V. So problem is probably the BOD resetting below 2.7V.
I advise to update bootloader to use a 1MHz version and remove BOD or set it to lower value. Using an arduino nano as a programmer (with ArduinoISP sketch) it is very easy.
Then just use i2c sensors to allow low voltage and you just need to sleep all the time except a fraction of a second at every measurement. With that you get years of battery life.
I use CR2032 for door and temp/hum/light sensors and my oldest sensor on my entrance door is nearly one year old and voltage of battery is less than 0.1V down, on a chinese low quality cell.
