Project powered by Batteries

[raulandresmoch]

Hello, so Im planning to build an small Hum/Temp sensor, but it cant be powerd by usb it has to be done with Batteries, I will use an small Arduino Pro Mini with a NrF24 and a DHT11 Sensor, my question is do I need to modify the "My sensors" code for the Batteries to last some time?! I will be using a 3 AA batteries........... Thank you so much!!!

[gohan]

Why don't you use a better temp/hum sensor that can work with lower voltages? If you want good battery life you need to get rid of pretty much all voltage regulators (also the one on board of the pro mini 3.3v). As an extra, you could also use a single LiFePo4 battery to power everything. For the code part, just use the sleep function at the end of loop.

[dbemowsk]

@raulandresmoch Have a look at this thread. I have done a couple of these for my house. I use an I2C temp and humidity sensor. They are much better for battery operated nodes. The one I used was an HDC1080. Another common one that people here use is the BME280.

If you are at all interested in the 3D printable wall box that I used in mine, I have the box posted on thingiverse.

[raulandresmoch]

@dbemowsk said in Project powered by Batteries:

HDC1080

Thank you for your help!!! Here in Mexico I just cant find those sensors, so I will order on Aliexpress, but for know I have to use DHT sensors, I will get rid of regulators and LEDs to save some power. Do you use PRO MINI on your nodes?! I have no idea where to weld the power input from the batteries to the pro mini, If I have like 4 AA Batteries in series can I put them directly to the Arduino board?!?! Sorry for all the questions but Im pretty new at this!!! I saw you 3D design, Its is for UNO?! Best regards.

[raulandresmoch]

@gohan Because I just cant find other sensors here in Mexico, I will buy some in Aliexpress, but for know I have to work with DHT sensors, I will get rid of the regulators on the Arduino and also the LED, do you think than a LiFePo4 has the juice to power the arduino, sensor and the NRF24 antenna?!? I will modify the code so it gets to sleep for almost all day, I will put to mesure only like 1 time each hour or something like that.......

[gohan]

I have an AA LiFePO4 battery powering a NRF24 node that sends temp, humidity, voltage and battery level every 10 minutes and it hasn't dropped 0.01v in a month

[mfalkvidd]

@raulandresmoch if you haven't already, look at https://www.mysensors.org/build/battery for info on how to get long battery life from a pro mini.

[dbemowsk]

@raulandresmoch The 3D design is for the Easy Newbie PCB designed by @sundberg84. The board carries an arduino pro mini and the nRF24L01+ radio.