Access temperature sensor data via RF

[peterodeus9]

Posted on October 19, 2015 at 15:37

Hi, How do I access the temperature sensor data, available on the M24LR-Discovery, via RF?

Generally I'm interested to learn how the failing Demo Datalogger could be made to work using M24LR-Discovery...But more specifically I need the usable transceive commands for the temperature sensor data to be returned when accessing M24LR-Discovery from Android using RF...Any help deeply appreciated! Peter #rf-sensor-data-m24lr-android

[peterodeus9]

Posted on October 20, 2015 at 08:57

...Being on a learning path coming from the Android world I'm very eager to learn the absolutely best practices of accessing custom firmware via RF. Especially when it comes to the android side being in absolute control as to when the sensor device can be active to do its work.

So. In the best of worlds I'm expecting an RF command from Android to trigger sensor data to be returned as a direct response to that specific command. Just like how the standard commands work when accessing the user area memory.But is that mental model of mine just not true? Maybe I'm supposed to write some byte into the memory, wait for a while and finally poll for some sensor data result?Any advice welcome. Even info whether the M24LR-Discovery is even usable for developing and testing custom sensor data retrieval (temperature, voltage...) using RF.:). Peter.

[peterodeus9 · Accepted solution]

Posted on October 21, 2015 at 11:11

Had a look into stsw-m24lr009\M24LR64-R Datalogger Application Firmware and found that the MCU writes temperature data into the EEPROM every [user-defined] second. Hence, the user can only poll for sensor data written by the MCU without having ad-hoc control over the rate of recurrence (besides every x second).

And spontaneous ad-hoc control over the MCU is what I'm looking for.So. Given page 23 of ref. 1, ''Digital output (MCU wake up)'' ... correlated with chapter 4.3.1 of ref. 2, ''RF WIP/BUSY pin configuration'' ... It seems to me that an MCU can be arranged to receive a wake-up call by utilizing the RF WIP/BUSY pin, effectively making the RF client device to control when the MCU should do it's work. 1. http://www.st.com/web/en/resource/sales_and_marketing/presentation/product_presentation/NFC%20memories%20and%20transceivers%20-%20Product%20overview.pdf2. http://www.st.com/st-web-ui/static/active/en/resource/technical/document/datasheet/DM00038059.pdf?s_searchtype=keywordHopefully on the right track. Comments welcome. Peter.