Electronics Questions not on EE
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1 answer

(ARM assembly) Shifting a register right 1 sets all bits to zero

I feel like I'm going crazy. I'm attempting to write a function which simulates hardware floating point addition in ARM assembly. I have a function float simulate_fp_add(float, float) which currently …

31 mins ago
1 answer

What abstraction level should the servo transitions have?

I think I'm using too many methods because of a poor abstraction design. That's why I'm asking this question, different than this one and similar ones, which only focus on the number of methods per …

47 mins ago
0 answers

Can I use a squashfs file sitting on a hard disk as my rootfs?

I need to do remote updates on an embedded Linux box that has its rootfs on /dev/sda1. My first thought was to add an update partition and switch to it on update, but for reasons specific to our …

0 answers

Ho do you verify the correctness of an API?

On an embedded system , say I design an API that returns the frequency at which the CPU is running or the API returns some hardware related data, how do you check the value returned is accurate. I ...

1 hour ago
1 answer

A good C library for speeding up AT commands with a GSM module in embedded linux?

I used to work with GM862-QUAD-PY module from Telit (link here: http://www.telit.com/en/products.php?p_ac=show&p=4). This module has a built-in Python interpreter. For a long time, I use it as a …

1 answer

Dynamically switch between programs Arduino

I have a question regarding how to use a mechanical switch to change programs in an Arduino unit. I am currently making a wireless follow focus device that will use xbee to connect to another Arduino …

2 hours ago
2 answers

What's the physical meaning of the imaginary component of impedance?

As you know, impedance is defined as a complex number. Ideal capacitors: $$ \frac {1} {j \omega C} \hspace{0.5 pc} \mathrm{or} \hspace{0.5 pc} \frac {1} {sC} $$ Ideal inductors: $$ j \omega L ...

0 answers

Android error with bluetooth

I'm developing an app with eclipse and arduino which connects to a bluetooth module. I can then control the LEDS on the board. However my code shows no errors but the app force closes everytime I hit …

2 answers

In ARM Processor, How to determine if a shift is right or left shift?

I am working on a software-based implementation of ARM processor in C. Given an ARM data processing instruction: instruction = 0xE3A01808; 1110 0 0 1 1101 0 0000 0001 1000 00001000 …

3 hours ago
2 answers

received items from bluetooth not as printed ones

i am developing a project that i send some numbers via bluetooth to the arduino mega board, so when i print the sent items directly they show correct. but when i store these numbers in an array and …

4 hours ago
0 answers

PIC18f2520 + HCSR04

I'm developing one simple code of HC SR04 for PIC18f2520 for received valores in cm. The situation is, i'm received the wrongs valores and not change with the approximation. The sensor give values …

1 answer

HC-05 bluetooth RSSI not working with Arduino

I cannot get my HC-05 bluetooth modules to output RSSI values. I issue it the following commands in series: AT+INIT -> *OK* AT+INQM=1,9,48 -> *OK* AT+INQ -> *No response, it starts ...

5 hours ago
1 answer

Optimizing ARM Cortex M3 code

I have a C Function which tries to copy a framebuffer to FSMC RAM. The functions eats the frame rate of the game loop to 10FPS. I would like to know how to analyze the disassembled function, should …

5 hours ago
4 answers

How does the ARM architecture differ from x86?

I have been hearing much about the ARM and x86 Architectures. Is the x86 Architecture specially designed to work with a keyboard while ARM expects to be mobile? What are the key differences between …

6 hours ago
1 answer

Linux Ip Forward on embedded system

I have an embedded Linux box with two network interfaces: usb0 and eth0. My ubuntu PC is connected to the usb0 interface using NDIS - so its really Ethernet over USB. The embedded box's eth0 is ...

1 answer

Two variables in a makefile target

I would like to specify a makefile target with more than one automatic variable but I do not know how to do it. For example: build/%_$(MPU).o: %.c ${MP_CC} $< -o $@ -c -mcpu=$(MPU) ...

3 answers

CodeBlocks for Arduino: No such file or directory

My problem is basically this: I have installed CodeBlocks with the Arduino plugins and can compile and run the test program (blinking LED), now I am trying to write a test program that uses the ...

7 hours ago
0 answers

Install i386 program on Samsung Arm Chromebook

I have installed Ubuntu 12.04 with Crouton on my Samsung ARM Chromebook for the sole purpose of installing either Foxit PDF or Adobe Reader. Unfortunately, both of these are i386 architecture. Is ...

7 hours ago
1 answer

Is there any gcc compiler primitive for “svc”?

I'm working on writing a program running on Cortex-m3. At first I wrote an assembly file which executes 'svc'. svc: svc 0 bx lr I decided to use gcc's inline asm, so I wrote it as follows, …

7 hours ago
0 answers

Android signal to Arduino bluetooth shell

My team and I are currently trying to get our android app to send a signal to our arduino with a bluetooth shell on it. The signal doesn't need to be meaningful in anyway only that the arduino knows a …

0 answers

Consume c# WCF Service in c++

I have a solution with 3 projects. 1 is a c# Console App which acts as the WCF Host, the 2nd is the c# WCF Service Library and my third is a UI which is generated using XAML Tools for Windows Embedded …

0 answers

Writing an external program to interface with wpa_supplicant in C++

As I understand it one can simply link wpa_ctrl.c into an external program and then you are able to use it's functions to control and receive information from wpa_supplicant. Could someone please ...

1 answer

RTOS - pending on different data in a queue

I'm programming a board from TI, and I'd like to somehow be able to have two different ISR's post to a task's message queue. That part works fine. However, on the receiving end, is there any ...

1 answer

Is there a standard way to send data with light pulses?

I'm looking at writing something for Arduino (having played extensively with Pi). One of the things I'd like to do is be able to set up the Arduino's wifi using a desktop computer. What I was ...

9 hours ago
1 answer

TrustZone monitor mode and IFAR, IFSR, DFAR, DFSR

The ARM TrustZone monitor mode can trap aborts in monitor mode. The monitor mode always executes in the secure world or context. How can we know what address and reason caused a fault in the normal …

9 hours ago
1 answer

Running scripts in u-boot with qemu on arm

I'm working with u-boot on ARM using QEMU. I'm using the 'versatilepb' machine since both Linux and u-boot work well with it. I would like to write a script to handle some of the boot procedures (set …

9 hours ago
2 answers

Win CE 7 application development

I have requirement that we need to develop a rich UI application(similar to WPF or silverlight). The target device is having embedded OS Win CE 7. how can i achieve this, after so much R&D i got …

2 answers

How to check/adjust SSH server on embedded board

I'm currently having difficulties connecting to an embedded board from my Linux machine through ssh. The embedded board is a FOX G20 V with a Linux OS. I've tried to connect to the board through ...

2 answers

Reading serial data from an Arduino

I'm trying to read serial data from my Arduino using Java. I have followed the tutorial Arduino and Java. So far I have it working except, I'm not reading the whole of the serial data at once. For …

9 hours ago
1 answer

Making arduino only write when signaled (serial)

I'm trying to communicate between a Raspberry Pi and Arduino with USB serial, but I only want the Arduino to write when the RPI sends a signal. My arduino code is as follows: int sensorPin = A0; …

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