embedded

How to start off with ARM processors?

Is it advisable to directly start off with the datasheet and user manual of an ARM processor for a newbie or first get an idea about the ARM world and then go ahead? ...

synchronization between two tasks

This is actually a design question for firmware in an embedded system I have two ISRs (of same priority) executed independently . These ISRs are triggered when the h/w generates data. I want a mechanism which must be put in place to synchronise between task1 and task2. task 2 must know about the certain values calculated in task1 which ...

We have to use C "for performance reasons"

Hello StackOverflowers of the World, In this age of many languages there seems to be a great language for just about every task and I find myself professionally struggling against a mantra of 'nothing but C is fast' where fast is really intended to mean 'fast enough'. I work with very rational open minded people who like comparing numb...

Development kit for Bluetooth which allows customisation of the modulation algorithms.

We need to perform some experiments on the Bluetooth protocol, and for this we need a development kit which allows us to implement/modify different parts of the Bluetooth protocol stack. We have been looking at the TI MSP430 Wireless Development Tool (EZ430-RF2500). This kit contains a MSP430 MCU and a CC2500 multi-channel RF transceive...

Keil vs GCC for ARM7?

How does Keil compare to GCC for ARM7 development? I'm in the process of choosing hw consultants for a medium size project and some use keil and some use gcc. I'd like to know the gotchas involved in going with either option... ...

What microprocessor for experimentation?

I harbor a secret fantasy (oops, not so secret anymore) to build a simple computer from scratch. I'm looking for an easy-to-use microprocessor to start with. I know about the usual suspects such as the 6502, 68000, 8086, Z80, etc. But I'm wondering if something better is out there. Here's my wish list: Must have: Low clock rate (4-25 ...

How do you test your interrupt handling module?

I've got an interrupt handling module which controls the interrupt controller hardware on an embedded processor. Now I want to add more tests to it. Currently, the tests only tests if nesting of interrupts works by making two software interrupts from within an ISR, one with low priority and one with high priority. How can I test this mod...

total size of the contents of all the files in a directory

When I use ls or du I get the amount of disk space each file is occupying. I need the sum total of all the data in files and sub directories I would get if I opened each file and counted the bytes. Bonus points If i can get this with out opening each file and counting. ...

Python/mySQL on an Embedded ARM9 Device?

I have an application where a small embedded ARM9 device (running Linux) must gather information from sensors and then connect to a remote mySQL database and INSERT the data. I have Python 2.5 running on the ARM9 device fine. I have developed a prototype application in Python 2.5 running on x86 Windows and it connects with mySQL and INSE...

Help with deciphering shorthand C

I'm trying to figure out some things with some firmware that was written for us. I'm not all that familiar with C and I think there's some shorthand going on here that I'm just not getting. I don't understand how the code relates to the comments, particularly how you get 70ms from any of that. Can you help translate into English? // s...

Can you explain this Embedded MATLAB Function error?

I'm having a problem sending a value from a GUI to an Embedded MATLAB Function (EMF) in a Simulink model. I get this value from a slider in my GUI and send it to an EMF block in my model. I can confirm that the value is being transferred correctly from my GUI to my Simulink block, since I can display the value with a display block in my ...

Using Haskell for sizable real-time systems: how (if?) ?

I've been curious to understand if it is possible to apply the power of Haskell to embedded realtime world, and in googling have found the Atom package. I'd assume that in the complex case the code might have all the classical C bugs - crashes, memory corruptions, etc, which would then need to be traced to the original Haskell code that ...

What is the best way to explain bit manipulation to the students?

I am currently planning to conduct a Training Workshop on Optimized C Code for Microcontroller Applications. Currently I am stuck on how to explain bit manipulation in C? Exactly what I don't want is to lead students to bit structure but guide them to use bit manipulation efficiently... Any advice? ...

Does the .NET Micro Framework support the CAN bus?

I know that the .NET Microframework supports the I²C bus. Are there some libraries for CAN or CANOpen too? If not, does it support CAN without using other peripherials? Can I build CAN support myself? Regards, Markus ...

Embedded Systems Podcasts

Are there any good podcasts focused on discussing issues of particular relevance to the development of embedded systems? ...

Avoiding global variables in embedded programming

In the type of embedded programming I'm getting into, determinism and transparency of the running code are highly valued. What I mean by transparency is, for instance, being able to look at arbitrary sections of memory and know what variable is stored there. So, as I'm sure embedded programmers expect, new is to be avoided if at all pos...

Learning embedded systems from the ground up

Hi, I am fourth-year studying for my undergraduate in Computer Science, and I wanted to start learning about embedded systems and programming. I have been looking at various university courses (UCSD, MIT, etc.), but there is a lot of focus on hardware. I don't mind learning the hardware, but throughout my studies, my degree has almost...

How to get GNU AS to emit per-line debugging info or GDB to single step lines in (AVR) Assembly?

I cannot figure out how to get GAS to emit line number debugging information for gdb in assembly. Note that I'm using the avr-gcc cross compiler, but doubt that is relevant. I'm using the following command line options to assemble: avr-gcc -g -ggdb -Os -mmcu=atmega644 -ffunction-sections -fsigned-char -Winvalid-pch -Wall -Wno-long-lo...

Are there conclusive studies/experiments on C compilation using a C++ compiler?

I've seen a lot of arguments over the general performance of C code compiled with a C++ compiler -- I'm curious as to whether there are any solid experimental studies buried beneath all the anecdotal flame wars you find in web searches. I'm particularly interested in the GCC suite, but any data points would be interesting. (Comparing the...

Embedded system projects for experienced programmer

I had been working as an embedded systems software engineer for 5 years (more of CAN and core level programming, I2C, SPI) and I took up a graduate program. Currently I work as an application software programmer which is also interesting. But, the fun and the satisfaction that I had with embedded systems projects is missing. I would like...