Segger ⁽⁸⁾

Having got the BLE Lightbulb peripheral example working as I wanted it to on the nRF52 development kit (PCA10040), the next step was to get my other dev kit to be the controller for it, in place of the smartphone app. NovelBits helpfully provides all the code for this on the page How to build the simplest nRF52 BLE Central (Lightbulb use case) but it is targeted at the nRF52840 and SDK 15. I only had one nRF52 dev kit and one nRF51 dev kit. As I learned previously, the nRF51 is only supported by SDK version 12, so I had the job of porting the example code down from SDK version 15 and changing it over to the smaller, M0 based chip. At the same time, the Softdevice (BTLE stack) changes from s132 to s130. My plan was to…

SES Include File Manager A simple helper application for use with Segger Embedded Studio when working with the Nordic Semiconductor SDK. The application checks which paths exist and allows you to remove those that don’t, allows a search by filename to show which folder they are in, and allows conversion between relative and absolute paths for the include folders. (It does not search your SDK folder for include files to automatically add them to the include paths.) The Nordic SDK folder is structured so that many include files which are needed for a project are in different folders. All of the folder paths need to be added to the c_user_include_directories definition for the project to compile. It is time consuming to search for each include file that a compile will complain about being missing so that it’s path can be…

Segger Embedded Studio project files appear to be XML formatted with a custom DOCTYPE. <!DOCTYPE CrossStudio_Project_File> <solution Name="ble_app_MA_lightbulb_pca10040_s132" target="8" version="2"> <project Name="ble_app_MA_lightbulb_pca10040_s132"> <configuration Name="Common" arm_architecture="v7EM" arm_core_type="Cortex-M4" arm_endian="Little" arm_fp_abi="Hard" arm_fpu_type="FPv4-SP-D16" arm_linker_heap_size="8192" arm_linker_process_stack_size="0" arm_linker_stack_size="8192" arm_linker_treat_warnings_as_errors="No" ... /> <configuration Name="Debug" c_preprocessor_definitions="DEBUG; DEBUG_NRF" gcc_optimization_level="None" /> </solution> Reading In VB.NET, Private xmlDoc As XmlDocument = New XmlDocument() xmlDoc.PreserveWhitespace = True xmlDoc.XmlResolver = Nothing xmlDoc.Load(filename) Once the XML is loaded, an attribute such as c_user_include_directories can be read using this syntax sIncludes = xmlDoc.SelectSingleNode("solution/project/configuration[@c_user_include_directories]").Attributes("c_user_include_directories").Value Writing However, writing out an this XML document object back to a file has a few problems. The DOCTYPE tag changes in that additional square brackets [] appear at the end due to a bug in the .NET framework, so you get <!DOCTYPE CrossStudio_Project_File []> which although is valid XML, causes SES to say that the file is not a valid project.

In the previous post on using a BLE peripheral example, the LED2 could only be controlled in terms of two states, On and Off. With my background of lighting controls, I wasn't satisfied that this could be called a BLE lightbulb project without at least brightness control. Since the example BLE code is already set up to send a byte as the BLE characteristic value, it should be easy to expand the example to brightness control in percentage terms using the byte in the range 0 to 100. The main addition to the previous project is the PWM software module which sets up and controls the internal PWM hardware peripheral on the nRF52832. It is better to use an existing software module which encodes all the knowledge necessary to set up the PWM peripheral rather than just accessing the registers directly…

I was getting a little frustrated with the Nordic examples and tutorials all being not quite ready for use. Not as badly frustrated as this guy but there always seemed to be some mismatch between what was required and what I was using, even when I chose the preferred tools. OK, I made a mistake assuming that I should start with the nRF51-DK because that is a smaller, simpler, cheaper chip. Although when you look into pricing, you find that nRF51's are not necessarily cheaper So I got myself onto the nRF52-DK so that I could use the latest SDK 16 and the Segger SES toolchain, which meets all the requirements in the Getting Starting guide. After going through that, I wanted to find a tutorial that was written from outside Nordic Semi so that it could be more objective about the tools.