embedded

问题 I'm trying to override the OnPaint events of the windows form in .NET Compact Framework . So far, I'm able to draw the controls with gradients, rounded rectangles etc that would not normally be possible with regular controls. However, I'm having problems when I want to make a control invisible. Right now, what I do is re-draw all the controls except those invisible ones. Since it takes a bit of time, it causes some flicker. Does anyone know how windows handles painting the "invisible"

问题 I'm working on bringing linux to a custom Cortex-M7 board with 16 Mb of SDRAM and 64 Mb of Flash. The platform has no-MMU, no shared libraries, FLAT executables. I'm having problems booting a Busybox system with very simple init.d shell scripts. The system is running out of memory by executing simple shell commands like "[" or "printf". It turns out that everytime one of these commands are executed the system needs to load the FULL, one and only busybox executable (650 Kb on my system). So

问题 I m planning to create a centrex system app in android. In which there is a voice mail will set in the receiver side. By the instructions in the voice mail, caller has to press the number in the dial pad, receiver side should identify the number and do the corresponding actions. Does anyone have any idea about how to detect the number pressed by the caller in receiver side?, What is the technology behind it?, Is it possible in android? Any help will be appreciable.. 回答1: Decoding DTMF is

问题 Currently, on my embedded system (coded in C), I have a lot of debug-assistive print statements which are executed when a remote tool is hooked up to the system that can display the messages to a PC. These help to understand the general system status, but as the messages are going over a slow CAN bus, I believe they may be clogging the tubes and causing other problems with trying to get any useful data logged. The basic gist of it is this: It's like a printf, but ultimately in a special

问题 I'm having a lot of trouble installing Java on my Poky Linux system. I'm building my system using Yocto with the following configuration: local.conf MACHINE ??= "intel-corei7-64" DISTRO ?= "poky" PACKAGE_CLASSES ?= "package_rpm" SDKMACHINE ?= "x86_64" EXTRA_IMAGE_FEATURES ?= "debug-tweaks" USER_CLASSES ?= "buildstats image-mklibs image-prelink" PATCHRESOLVE = "noop" BB_DISKMON_DIRS = "\ STOPTASKS,${TMPDIR},1G,100K \ STOPTASKS,${DL_DIR},1G,100K \ STOPTASKS,${SSTATE_DIR},1G,100K \ STOPTASKS,

问题 I'm new here and I'm trying to solve my projects problem. I'm trying to send send data over UART from Raspberry Pi B+ to my STM32F407 and process that data in real-time. My problem is: How to actually synchronize main() thred and UART interruption handler not to stop for a long time my UART interruption. Data sent from Raspberry looks like (where n is number): nwnx Code: void UART4_IRQHandler(void) { if(USART_GetITStatus(UART4, USART_IT_RXNE)) { if(!flag) { processing = true; widthTemp[j] =

问题 I need some help speeding up writing to serial. I found a few similar questions to this but nothing that dealt with the Processing language or Java so I'm hoping someone can help me with this issue I have. edit As John points out below, it appears serial just isn't fast enough to send this much data at the speed I want. Does anyone know of other arduino interfaces that are available? end edit I am using an arduino to control a grid of 400 RGB LEDs I have hooked up. To send commands to the

问题 So I'm working on a small ARM embedded system that has pretty limited memory, and no MMU. I have several objects that I need to dynamically allocate for different functions that all inherit from the same superclass, but perform different functions and are likely different sizes. I don't have enough memory available to instantiate them all at startup and leave them in place. So as an example, I might have objects defined sort of like: class Waveform1 : public OutputStream class Waveform2 :

问题 I'm working on some embedded code for a class project that currently (per requirements) creates a number of srec files and merges them. I'd like to be able to load this code into QEMU, but it is generally only happy with ELF files. What is the esiest way to merge the original ELF files instead of the srecs. Also acceptable, a method to convert the srec back into an ELF and have the resulting file be loadable (objcopy seems to produce fairly broken files doing this (no architecture amoung

问题 I am using sqlite in my compact framework application to log the events in system. I am also using System.Data.SQLite. The event has the time stamp to describe at what time it occurred. I am storing this Time stamp as Ticks in my table. Along with this column the table contains another 5 columns of integer/text type. Below is table schema CREATE TABLE T1 (TimeStamp INTEGER, Col2 INTEGER, Col3 INTEGER, Col4 INTEGER, Col5 INTEGER, Col6 TEXT, PRIMARY KEY(TimeStamp DESC)); I am querying for the