I’ve used both uIP and lwIP extensively. uIP Great if youre only wanting something basic like a bootloader Small footprint. Uses polling so we’ve never got over 3kbit with it 🙁 No DHCP ‘out of the box’ Poor UDP support lwIP Fully interrupt driven so much faster (~ x10) Includes DHCP with failover AutoIP UDP … Read more
Normally, an interrupt service routine proceeds until it is complete without being interrupted itself in most of the systems. However, If we have a larger system, where several devices may interrupt the microprocessor, a priority problem may arise. If you set the interrupt enable flag within the current interrupt as well, then you can allow … Read more
The other possibility i can think of is: 1.Your process is running more than one thread. For eg – 2 say x & y. 2.Thread y hits the break point but you have attached gdb to thread x. This case is a Trace/breakpoint trap.
Dual issue means that each clock cycle the processor can move two instructions from one stage of the pipeline to the next stage. Where this happens depends on the processor and the company’s terminology: it can mean that two instructions are moved from a decode queue to a reordering queue (Intel calls this issue) or … Read more
So, I actually found the answer. To find out what the device name is, I did an ls of the /dev/ directory with the device plugged in and then with it disconnected. ls -lha /dev/tty* > plugged.txt ls -lha /dev/tty* > np.txt Then I compared the files using vimdiff plugged.txt np.txt And saw the line … Read more
Just my 2 cents… I consult exclusively on embedded systems, most of them hard real-time and/or safety/life critical. Most of them run in 256K of flash/ROM or less – in other words, these are not “PC-like” VME bus systems with 1GB+ of RAM/flash and a 1GHz+ CPU. They are deeply embedded, somewhat resource-constrained systems. I … Read more
Personally, I’d recommend an ARM Cortex-M3 based microcontroller. The higher-power ARM cores are extremely popular, and these low-power versions could very well take off in a space that is still littered with proprietary 8/16-bit cores. Here is a recent article on the subject: The ARM Cortex-M3 and the convergence of the MCU market. The Arduino … Read more
If you are completely new to kernel development, i would suggest not starting with hardware development and going to some “software-only” kernel modules like proc file / sysfs or for more complex examples filesystem / network development , developing on a uml/vmware/virtualbox/… machine so crashing your machine won’t hurt so much 🙂 For embedded development … Read more
Remember that assignment is done right to left, and that they are normal expressions. So from the compilers perspective the line sample1 = sample2 = 0; is the same as sample1 = (sample2 = 0); which is the same as sample2 = 0; sample1 = sample2; That is, sample2 is assigned zero, then sample1 is … Read more
Today AVR and PIC are probably the most common microcontrollers among hobbyists. Both have a very wide range of device variants and both can be used to achieve similar results. For a beginner I would suggest AVR due to various reasons: AVR family (tiny, mega) is coherent and easy to understand. The architecture is powerful … Read more