- Sat Nov 12, 2016 1:43 am
#58015
Hi Dan,
thank you for the input.
That's a valid point. I on the contrary had very good experience with the NRF24L01. Since the sending of data only takes a few milliseconds it works fine even on crowded frequency bands: the module auto-retransmits the message up to 16 times if it did not go through to the base station. The only down-side I see is the range inside of buildings with thick walls.
I did consider the RFM69 module in the beginning but chose the NRF24L01 because it uses less than half the power for transmitting which is a huge advantage when running off of coin cells. The RFM69 draws 45mA which is more than what a coin cell can handle, voltage will drop about 1V due to battery resistance and unless the battery is fresh the voltage becomes too low to send the data reliably. The second point was the antenna which is integrated in the NRF24L01 modules at about the same size of the RFM69 without an antenna.
Thanks for the tip with Cayenne, I did not know that particular IOT platform and will definitely try it.
A friend of mine already started with a custom website that can display and store data from the sensors. Right now it is still more of a proof of concept but it works great!
Here is how the setup process works:
-get an API key from the website
-Enter the wifi credentials and the API key on the configuration page of the AlphaNode (acts as an accesspoint if no wifi connection can be established)
-The Alpha node auto-detects and registers all sensor nodes present locally as well as on the web site
-Data is streamed to the site which then displays available sensor values and plots the selected values
-Data is also stored locally in a file on the SD card
thank you for the input.
danbicks wrote:I am not sure I would have chosen the NRF24L01, poor experience with these devices in my case and already a seriously overcrowded frequency, I would have opted for an RFM69 type solution, allowing a broad range of frequency's for communication.
That's a valid point. I on the contrary had very good experience with the NRF24L01. Since the sending of data only takes a few milliseconds it works fine even on crowded frequency bands: the module auto-retransmits the message up to 16 times if it did not go through to the base station. The only down-side I see is the range inside of buildings with thick walls.
I did consider the RFM69 module in the beginning but chose the NRF24L01 because it uses less than half the power for transmitting which is a huge advantage when running off of coin cells. The RFM69 draws 45mA which is more than what a coin cell can handle, voltage will drop about 1V due to battery resistance and unless the battery is fresh the voltage becomes too low to send the data reliably. The second point was the antenna which is integrated in the NRF24L01 modules at about the same size of the RFM69 without an antenna.
danbicks wrote:A key point of focus would be to have an IOT website enabling users to create their own dashboards with instant message hooks, triggers based on device data etc. Bit like Cayenne! That is the road I would focus on.
Thanks for the tip with Cayenne, I did not know that particular IOT platform and will definitely try it.
A friend of mine already started with a custom website that can display and store data from the sensors. Right now it is still more of a proof of concept but it works great!
Here is how the setup process works:
-get an API key from the website
-Enter the wifi credentials and the API key on the configuration page of the AlphaNode (acts as an accesspoint if no wifi connection can be established)
-The Alpha node auto-detects and registers all sensor nodes present locally as well as on the web site
-Data is streamed to the site which then displays available sensor values and plots the selected values
-Data is also stored locally in a file on the SD card
