STM32 + BLE module for super low energy application

Thread Starter

zazas321

Joined Nov 29, 2015
736
Hey. I would like to get some advice regarding the selection of the bluetooth module for the low power STM32 microcontroller. I also would like some general advice regarding the STM32 and bluetooth modules.

I need to send some data on my STM32 few times a day, therefore I thought the best selection would be the STM32L series since they have low power consumption.
I need to have BLE module connected to the STM32. The BLE is waiting for someone to connect and then it has to wake up the STM32.
I want to know:
1. For example if there are some external events that also need to wake up the STM32 such as movement detection. Is it better to wire this sensor to bluetooth module and once detected send wake up signal to the STM32? Since bluetooth module should always be ON (waiting for user to connect). Or is it better to connect the sensor straight to STM32 and somehow wake the microcontroller from low pow power mode when a movement is detected? Which one is more energy effiecient?

2.What BLE module would you advice me to use with the STM32. The only requirements are super low power usage and bluetooth 4.0 support.
 

Thread Starter

zazas321

Joined Nov 29, 2015
736
Mostly considering between CC254x or nRF bluetooth IC. Some bluetooth IC's require an additional microcontroller and some do not.

I am wondering which one is more power efficient? If a bluetooth module requires an additional microcontroller, does that mean that it relies on the external microcontroller to be powered ON? Can someone clarify this for me please? What exactly are the differences between the bluetooth IC that works independently and the bluetooth IC that needs external microcontroller?

I mainly need the external microcontroller to read some sensors, send data when it is waken up but I believe this could be accomplished with independant bluetooth IC since it has GPIOs. But I am not sure whether it has deep sleep funcionality GPIO wise to save as much energy as possible such as STM32L series ( being able to wake up thorugh the RTC interrupt every few hours or so, as well as external hardware interrupt)
 
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