S2LP RF API implementation example

Description

This S2LP RF API is a low level implementation example of the Sigfox EP library, showing the manuf/rf_api.c file implementation for the S2LP transceiver from ST-Microelectronics.

[!WARNING]
The resulting radio performances of your device strongly depends on your hardware design (schematic, PCB routing, crystal oscillator placement, good RF practices, etc...). Sigfox certification remains mandatory whatever the software embedded in your device (including the Sigfox End-Point library and its implementation examples).

The table below shows the versions compatibility between this radio example and the Sigfox End-Point library.

S2LP_RF_API	EP_LIB
v3.1	>= v3.6
v3.0	v3.5
v2.0	v3.5
v1.3	v3.4
v1.2	v3.2 to v3.3
v1.1	v3.2 to v3.3
v1.0	v3.2 to v3.3

Architecture

Compilation flags for optimization

This radio example inherits all the Sigfox End-Point library flags and can be optimized accordingly.

The LOW_LEVEL_OPEN_CLOSE flag must be enabled to use this example.

How to add S2LP RF API example to your project

Dependencies

The S2LP RF API is based on the official S2LP driver from ST-Microelectronics. This driver exposes a functional interface to configure the chip registers, which is used to perform the Sigfox uplink modulation and optional downlink reception. It relies on low level functions (called board drivers) which need to be implemented to run on your specific hardware. There are divided in 2 groups:

S2LP_CORE_SPI : low level SPI access functions of the S2LP driver from ST.
S2LP_HW_API : additional hardware dependent functions required to get a generic RF API implementation of the S2LP.

The templates are located in the src/board folder.

Submodule

The best way to embed the S2LP RF API example into your project is to use a Git submodule, in a similar way to the library. The radio driver will be seen as a sub-repository with independant history. It will be much easier to upgrade the radio driver or to switch between versions when necessary, by using the common git pull and git checkout commands within the sigfox-ep-rf-api-st-s2lp folder.

In order to keep the repository clean, you will need to exclude the src/board folder from build (where the board templates are defined) and implement the functions in another location of your project.

To add the S2LP RF API submodule, go to your project location and run the following commands:

mkdir lib
cd lib/
git submodule add https://github.com/sigfox-tech-radio/sigfox-ep-rf-api-st-s2lp.git

This will clone the S2LP RF API repository. At project level, you can commit the submodule creation with the following commands:

git commit --message "Add Sigfox S2LP RF API submodule."
git push

With the submodule, you can easily:

Update the radio driver to the latest version:

cd lib/sigfox-ep-rf-api-st-s2lp/
git pull
git checkout master

Use a specific release:

cd lib/sigfox-ep-rf-api-st-s2lp/
git pull
git checkout <tag>

Raw source code

You can download or clone any release of the S2LP RF API example and copy all files into your project.

git clone https://github.com/sigfox-tech-radio/sigfox-ep-rf-api-st-s2lp.git

Precompiled source code

You can download or clone any release of the S2LP RF API example and copy all files into your project. If you do not plan to change your compilation flags in the future, you can perform a precompilation step before copying the file in your project. The precompilation will remove all preprocessor directives according to your flags selection, in order to produce a more readable code. Then you can copy the new files into your project.

git clone https://github.com/sigfox-tech-radio/sigfox-ep-rf-api-st-s2lp.git

To perform the precompilation, you have to install cmake and unifdef tools, and run the following commands:

cd sigfox-ep-rf-api-st-s2lp/
mkdir build
cd build/

Precompiling by reading the sigfox_ep_flags.h file:

cmake -DSIGFOX_EP_LIB_DIR=<sigfox-ep-lib path> \
      -DUSE_SIGFOX_EP_FLAGS_H=ON ..
make precompil_s2lp_rf_api

Precompiling by entering the flags selection on command line:

cmake -DSIGFOX_EP_LIB_DIR=<sigfox-ep-lib path> \
      -DUSE_SIGFOX_EP_FLAGS_H=OFF \
      -DRC1_ZONE=ON \
      -DRC2_ZONE=ON \
      -DRC3C_ZONE=ON \
      -DRC3D_ZONE=ON \
      -DRC4_ZONE=ON \
      -DRC5_ZONE=ON \
      -DRC6_ZONE=ON \
      -DRC7_ZONE=ON \
      -DAPPLICATION_MESSAGES=ON \
      -DCONTROL_KEEP_ALIVE_MESSAGE=ON \
      -DBIDIRECTIONAL=ON \
      -DASYNCHRONOUS=ON \
      -DLOW_LEVEL_OPEN_CLOSE=ON \
      -DREGULATORY=ON \
      -DLATENCY_COMPENSATION=ON \
      -DSINGLE_FRAME=ON \
      -DUL_BIT_RATE_BPS=OFF \
      -DTX_POWER_DBM_EIRP=OFF \
      -DT_IFU_MS=OFF \
      -DT_CONF_MS=OFF \
      -DUL_PAYLOAD_SIZE=OFF \
      -DCRC_HW=OFF \
      -DMESSAGE_COUNTER_ROLLOVER=OFF \
      -DPARAMETERS_CHECK=ON \
      -DCERTIFICATION=ON \
      -DPUBLIC_KEY_CAPABLE=ON \
      -DVERBOSE=ON \
      -DERROR_CODES=ON \
      -DERROR_STACK=12 ..
make precompil_s2lp_rf_api

The new files will be generated in the build/precompil folder.

Static library

You can also download or clone any release of the S2LP RF API example and build a static library.

git clone https://github.com/sigfox-tech-radio/sigfox-ep-rf-api-st-s2lp.git

To build a static library, you have to install cmake tool and run the following commands:

cd sigfox-ep-rf-api-st-s2lp/
mkdir build
cd build/

Building by reading the sigfox_ep_flags.h file:

cmake -DSIGFOX_EP_LIB_DIR=<sigfox-ep-lib path> \
      -DUSE_SIGFOX_EP_FLAGS_H=ON ..
make s2lp_rf_api

Building by entering the flags selection on command line:

cmake -DSIGFOX_EP_LIB_DIR=<sigfox-ep-lib path> \
      -DUSE_SIGFOX_EP_FLAGS_H=OFF \
      -DRC1_ZONE=ON \
      -DRC2_ZONE=ON \
      -DRC3C_ZONE=ON \
      -DRC3D_ZONE=ON \
      -DRC4_ZONE=ON \
      -DRC5_ZONE=ON \
      -DRC6_ZONE=ON \
      -DRC7_ZONE=ON \
      -DAPPLICATION_MESSAGES=ON \
      -DCONTROL_KEEP_ALIVE_MESSAGE=ON \
      -DBIDIRECTIONAL=ON \
      -DASYNCHRONOUS=ON \
      -DLOW_LEVEL_OPEN_CLOSE=ON \
      -DREGULATORY=ON \
      -DLATENCY_COMPENSATION=ON \
      -DSINGLE_FRAME=ON \
      -DPARAMETERS_CHECK=ON \
      -DCERTIFICATION=ON \
      -DPUBLIC_KEY_CAPABLE=ON \
      -DVERBOSE=ON \
      -DCRC_HW=OFF \
      -DERROR_CODES=ON \
      -DUL_BIT_RATE_BPS=OFF \
      -DT_IFU_MS=OFF \
      -DT_CONF_MS=OFF \
      -DUL_PAYLOAD_SIZE=OFF \
      -DMESSAGE_COUNTER_ROLLOVER=OFF \
      -DERROR_STACK=12 ..
make s2lp_rf_api

The archive will be generated in the build/lib folder.

sigfox-tech-radio / sigfox-ep-rf-api-st-s2lp

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