Electronics Questions not on EE
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2 answers

How the arm link register r14 works

I wanted to understand how arm link register works and how is it helpful in debugging. I started by writing a simple function. #define MACRO_TEST() ...

2 answers | 5 mins ago by user968000 on Stack Overflow stackoverflow.com
2 answers

How can you detect that an arduino is plugged into a computer?

Is it possible, on the arduino side, to detect that it's plugged into a computer? I've been looking around but no luck. If so how? and if not why?

2 answers | 6 mins ago by Jake Schievink on Stack Overflow stackoverflow.com
1 answer

Kirchhoff current loop in Resistor Diode Ladder network

I am looking for an approach on how to apply Kirchhoff current / voltage law in the infinitely long diode ladder network. Can anyone help me with this ? I am looking for 1D differential equation or …

1 answer

Arduino - count pulses without interrupt

I would like to know if there is a way to count digital pulses on an Arduino WITHOUT implementing an interrupt routine. Further description: I have a sensor that outputs digital pulses proportional …

2 answers

How to write an easy to expand set of color classes in C++

Background I'm working with a number of different displays (hardware) and different canvases (is that the plural of canvas?). Each can work with different colors. Example cases: RGB16 canvas -> ...

1 answer

Casting int to float results in illegal instruction

I'm using a MINI2440 board (S3C2440 CPU), running Linux. I have this working : double a=168.168; printf("\nsqrt(%f)=%f\n", a, sqrt(a)); But I have this resulting in "Illegal instruction" : float …

0 answers

PIC16f877a Timer0 code not working

i tried lately to make a program that uses timer0 to overflow from 255 to 0 and goto the isr code which will turn an led on if button on T0CKI pin was pressed for once as I was taught from microchip's …

2 answers

Can you replace floating points divisions by integer operations?

The Cortex MCU I'm using doesn't have support for floating point divisions in hardware. The GCC compiler solves this by doing them software based, but warns that it can be very slow. Now I was ...

2 answers | 3 hours ago by Muis on Stack Overflow stackoverflow.com
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Resistance and amperage

My problem is to solve the following exercise. First, if $R1 = R2$, then $I1 = 1.0\,\text{A}$. Now I have to find $I1$ if $R2 = 2 R1$. If $R1 = R2$ then I have got for the total resistance ...

0 answers

Time limit of an HTTP POST request

When sending an HTTP POST request, is there a time window in which all of the message body must be sent? I am sending many lines of data via an Arduino, and since I need to access an SD card to get …

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issues with Musical instrument shield vs1053 with Arduino (BLE 4.0)

I've had quite a tough time debugging my codes to output the correct sounds from my Musical Instrument shield vs1053 with Arduino (BLE 4.0 - Bluno). Basically, i'm doing a project that requires a MIDI …

0 answers

Eclipse AVR for arduino not uploading

I recently read this post about setting up Eclipse for Arduino. I Build the test project with no erros, but when I go to upload my test project it just hangs at 5%, with no error messages. If I ...

1 answer

Get the serial ARM CPU information with a C/C++ program

I can get the serial ARM CPU (Raspberry Pi) information with a C/C++ program. I could get this information from /proc/cpuinfo but then it is very easy to hack the program. Does anyone know how can the …

3 answers

Are there C functions or macros specifically designed to compile 1 to 1 with assembly instructions for bit manipulations in a cross-platform manner?

I've got a project involving emulation (If you look at my post history, you'll see how far I've come!) and I'm looking to do pseudo-binary-translation using C and playing with the optimizers and/or …

1 answer

Python System Requirements

I want to install python[2.7] on my linux device but I'm storage space conscious and need to know how much storage the software needs before I do so. I thought this would be an easy thing to look up …

0 answers

Write failed : broken pipe on ARM

I'm trying to insert a kernel module (which is kaodv.ko) into my ARM (Sabrelite). After I successfully cross compile my module, I want to insert it with insmod command. To do this, I've copy the file …

4 answers

Analyzing an ELF binary to minimize its size

I'm cross-compiling a V8 project to an embedded ARM target using the GCC arm-gnueabi cross compiler. I got the V8 library itself cross-compiled successfully, and as a smoke test I wanted to link it to …

4 answers | 7 hours ago by Matt Kline on Stack Overflow stackoverflow.com
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Running an ARM OS(CooCox) on X86 using qemu

I am new to qemu and have a board that uses the STM32F4103 processor. There is a program on it that runs on CooOS. I want to simulate the embedded code on an X86 machine and believe qemu is the way. …

0 answers

How to cross-compile libiconv for ARM Cortex M? Syntax errors in generated files

I'm trying to build libiconv as a static library for a Cortex M4 using the GNU ARM Toolchain and it seems the process is mostly successful. I configure libiconv thus: ./configure ...

2 answers

Using a configuration management tool to configure nodes without ssh

I'd like to manage the configuration of several devices running embedded Linux. There is a web server in my environment which has a SOAP interface I can use to get/set all the parameters of each of …

0 answers

Still receiving WARN util.NativeCodeLoader warning after compiling native library for Hadoop (ARM)

I was trying to get rid of this error below by compiling native libraries of Hadoop on ARM boards (odroid). 14/08/27 11:58:32 WARN util.NativeCodeLoader: Unable to load native-hadoop library for your …

0 answers

L6221E execution regions overlap error

I am working on Keil Vision4 and learning ARM Cortex-M3 assembly. Executing a program but have this error during the build process: .\mycode1.axf: Error: L6221E: Execution region ER_RO with Execution …

0 answers

I'm having trouble using an SD card with a Redbear Blend Micro

I'm trying to get an Adafruit SD card breakout to work with a Redbear blend micro board. I'm unsure how to wire it. I have it wired: CS - SS DI - 11 DO - 12 CLK - 13 GND - GND 3V - 3V What do …

6 answers

Does a current carrying wire produce electric field outside?

In the modern texts of electromagnetism in the presence of stationary currents the electric field is assumed conservative $\nabla \times E =0 $. Using this we get $E_{||}^{out}=E_{||}^{in}$ which ...

1 answer

Error when implementing AODV on ARM (SabreLIte)

I'm implementing the ad hoc AODV routing protocol on ARM based system Sabrelite http://boundarydevices.com/products/sabre-lite-imx6-sbc/ ......... After configuring and building the kernel that match …

1 answer

Why does gcc save r4 in arm FIQ interrupt handlers?

Consider the following C code: extern void dummy(void); void foo1(void) __attribute__(( interrupt("IRQ") )); void foo2(void) __attribute__(( interrupt("FIQ") )); void foo1() { dummy(); return; …

1 answers | 9 hours ago by Sven on Stack Overflow stackoverflow.com
1 answer

ARM without ALU how much for operations

I had a problem on ARM Cortex M3 with some functionality that requires multiply and divide natural numbers. The point is: if it's possible to make calculations between 128 bits numbers? I need to …

1 answers | 9 hours ago by Mazeryt Freager on Stack Overflow stackoverflow.com
1 answer

VirtualWire - Send Integer Array

how can I send and receive array of integers in Arduino using VirtualLibrary. I declared array like this: int toSend[] = {1,4,5,7,9}; How to correctly send and receive it? Maybe someone can help …

1 answers | 10 hours ago by Nikita Zernov on Stack Overflow stackoverflow.com
3 answers

ARM to C calling convention, registers to save

It's been a while since I last coded arm assembler and I'm a little rusty on the details. If I call a C function from arm, I only have to worry about saving r0-r3 and lr, right? If the C function ...

3 answers | 11 hours ago by richq on Stack Overflow stackoverflow.com
1 answer

Compiling rootfs for aarch64 on ubuntu

I am very new to ARM processor field. I have to port an application from x86 to aarch64. So I need to do a setup using some kind of a simulation because there is no hardware exists right now. Please …

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