STM32 Minimal Development Environment

Tags: ARM, Embedded, Programming

In the past I have written on the advantages of minimal development environments (read: Makefiles and GCC, no IDE, minimal abstraction layers) for ARM processors. One of the advantages of working this way is easy integration with existing processes such as build systems, production line, testing, etc. Using this in a virtualized environment also allows one to make sure every developer uses the same tools, and that the tools are tested and qualified for the intended project with a ready made virtual image available for each developer. They can then add their favorite editor and user interface, but the underlying build environment is fixed for everyone and archived as such on a per-project basis. This means that if a customer comes back a year or two later and wants to make a change, all the tools are there as we left them ready to make the change. In this blog post I'll write down a possible scenario for a typical STM32 project, in this case using a NUCLEO-L152RE board as a target. It should be easy to adapt to other STM32 boards/chips, and in general other ARM microcontrollers as well.

Programmer on chair

Progress!

Tags: Other

We've been busy these past few months. I've made some posts on LinkedIn, but I thought I'd recap those here and add some extra context. First of all, a business partner of ours is doing the RideLondon bike trip at the end of the month in support of a good cause called stem4. In addition, we will equip his bike with air quality sensors and track his ride. Read more about all of this here. Good luck Terence!

bicycle

Getting started with LoRa(WAN)

Tags: Embedded, Network, Wireless

It seems that LoRa(WAN) in general tends to be quite a source of confusion for those starting out with this technology. For starters, there is the difference between LoRa and LoRaWAN that are absolutely fundamental but often these terms are used interchangeably. In addition, there are many different starter kits and devices out there that are not necessarily compatible with each other. The need to build up a gateway network alongside building actual communicating devices doesn’t really help to make this all straight forward. Hopefully this text can help clear some of the confusion and get people to build both infrastructure and things (pun intended) on top of this promising network technology.

Slightly Smaller Still...

Tags: ARM, Electronics, Tracker

...and with even more features than before. 

Matchbox 2017

Some Thoughts on Securing IoT Devices

Tags: Cryptography, Embedded, Programming, Security

Security in the Internet of Things (IoT) leaves much to be desired. Some of the recent DDoS attacks such as those through Mirai on DNS provider Dyn or on popular security site KrebsonSecurity have been possible due to weak security measures in things like network connected cameras. There are many reasons why the situation is what it is today, but that will not be the topic of this entry. While we have seen some initiatives, notably the security guidelines (PDF) by NIST and some comments made by Bruce Schneier, I feel that this leaves a lot of people wondering what practical measures to take to secure their devices. Many companies in the IoT are start-ups lacking a proper understanding of what security in the embedded field entails, and might lack (or didn't plan for) the budget to hire dedicated security people. The goal of this blog entry are to (hopefully) lift the veil on some of the methodologies that should be employed to create more secure IoT systems from a very practical point of view.

IOT

Standard Peripherals Library vs CMSIS vs HAL vs Low Level Library

Tags: ARM, C, Electronics, Embedded, Programming

The STM32 line of microcontrollers offer a bunch of features in a nice package at reasonable cost, something I like. What I don't like as much are the development libraries around it provided by ST. For this reason, most of the time I stick to writing code using the 'Cortex Microcontroller Software Interface Standard' (CMSIS) and the datasheet, and this works nicely but can be slow to develop. While it's still my personal favorite, I recently checked out the other options to see where things are going to do the prep work for some ports of older projects built using the 'Standard Peripherals Library' to newer processors such as the STM32L4.

 

Microcontroller

 

Anyone Can Code...

Tags: Other, Programming

Every time I hear the "everybody can/should/has to code" line...

Anyone Can Code

Flashing STM32L15X EEPROM with STLink under Linux

Tags: Embedded, Linux, Programming

For a while now I've been evaluating some 32-bit micro controllers for a future product. One of them was the STM32L15x series. There are some handy development boards available such as the Nucleo boards. Since we need to have the ability to program processors from Linux for our small production line, tool support is one of the checkboxes that need to be ticked.

For the STM32 series, flashing the microcontroller can be done through GDB, OpenOCD, and the STLink tool. One issue that arose however was the need to program the EEPROM available on the STM32L series. This requirement comes from need to generate and program different EEPROM content on a per board basis at the production line. Doing that requires a few tweaks that are documented below...

Solutions

 

On Processes and Threads

Tags: C, Computer Architecture, Linux, Programming

Some time ago I followed an interesting discussion on a board where people were discussing multi-core software development. During the course of the discussion it became apparent that there is a lot of confusion and misconceptions about a 'process' and a 'thread' as they exist on e.g., a Linux system. Both are applicable to make use of multi-core systems, but they do so in different ways. Even though the exact distinction while compared to early definitions of the terms has perhaps become somewhat blurred, the two remain separate entities which can complement each other perfectly. In this post I'm going to try and illustrate the similarities and differences, and show you some real life scenarios of both. Keep in mind that we will be making some generalizations - and there are lots of examples where these generalizations do not directly apply, or where there are other possible implementations of the cited examples. Going into these would turn this blog entry into an entire book...

Multiprocess

Web Proxy

Tags: Network, Security

We just launched a free web proxy service: https://www.unblock-everything.com/. Not only will it help you get around firewalls and sites blocked by your ISP, it does so without logging user data. Oh, and we're 'Not Subject to American Law' - in reference to the recent NSA surveillance debacle ;-)

 

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