is an ARM 32bit RISC processor core for microcontrollers

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LPC1769 PC Communication

I am using LPC1769 micro controller and planning to use one of its serial (UART) port for PC communication. It has 4 UART ports (UART0,1,2 and 3) For PC communication purpose, can I use all ports or ...
2
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1answer
37 views

Howe to do a sam3x single channel ADC conversion

I have a Sam3x (Arduino Due hardware, but I don't use the Arduino IDE or libraries, and I don't use the Atmel libraries, just the register interface in sam.h). I have multiple pins configures as ADC ...
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1answer
38 views

3 mic sound direction locator solution?

I am building a robot toy. When a sudden surge of sound occurs, I wish to calculate the approx position of the sound source. I am going to place 3 analog mics on the edge of my round shape PCB, each ...
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2answers
113 views

Atmels AtSAM3s gets a bit warm running a test code on my dev board. Is there a problem?

I have a dev board developed by myself. I was using At91SAM7S256 but now I'm migrating to it's successor ATSAM3S8B. The MCU on the dev board for SAM3S gets warm. I am searching for someone with ...
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1answer
124 views

STM32 Standard Peripheral Library (SPL) - Modify SPI Configuration

I am using the STM32 SPL library with an STM32F103C8 microcontroller. As part of the project, I am using the SPI1 peripheral to interface with an SD card. Initially the SPI speed must be kept under ...
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44 views

LPC17xx internal pull-ups on JTAG etc

The the NXP LPC17xx Cortex-M3 family has internal pull-up resistors on some important pins such as the JTAG, NMI, Bootloader-select pin etc. While reading the data-sheet I learned that the pull-up is ...
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3answers
54 views

Finding maximum source impedance for A/D converter (SAM3X8E ARM Cortex-M3)

I would like to find out what is maximum recommended source impedance for A/D converter on Atmel SAM3X8E ARM Cortex-M3 microcontroller. I tried to follow the example of this excellent answer, which ...
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1answer
71 views

Cortex M3 GPIO address (LM3s300)

I had a little confusing regarding the address of GPIO_PortA As mentioned in datasheet: Based address of GPIO PortA:0x40004000 and GIOP_DATA has Offset : 0x000 which mean the address of GPIO_PortA = ...
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1answer
68 views

Necessary things in LPC1343 basic development board

I have finished my LPC1343 basic development board,just based on specs from datasheet and some referred from microbuilders.eu. I'm unsure if the board design is good or not so I've attached my ...
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1answer
120 views

LPC1788 external interrupt with CMSIS

There was a wide GPIO functions in the CMSIS initial versions which made easy setting and initialization of interrupts,like: ...
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1answer
221 views

differences between privileged mode and unprivileged mode in the RTX RTOS

As i said in the title what's differences between privileged mode and unprivileged mode in the RTX RTOS? And why in privileged mode threads has allowed full access to the cortex M processor?
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1answer
116 views

practical use of NMI in Cortex-M3

So some Cortex-M3 CPUs (and most other small CPUs as well) have a non maskable interrupt. I know what the NMI does, but I don't quite understand why I ever would want to use one. I'm looking for ...
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1answer
580 views

Storing a secure key in an embedded device's memory

I am working on an embedded device which send/receive data and stored them in ciphertext mode (encrypted mode ). Now what's best approach for storing Keys (I used ARM CORTEX M series MCU) ? 1-...
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2answers
79 views

ATSAM3N Cortex-M3 RAM Bit Banding

If i do not use Bit Banding feature on ATSAM3N, this region, it will used by the compiler for the program? Or it will stay unused? What if my program, randomly (by itself) should need to assign and ...
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1answer
234 views

External RAM with ARM Cortex M-3

I'm planning to start with uclinux with my ARM cortex M-3 based MCU . Uclinux's requirements include ~4MB of RAM (SRAM - DRAM - .. whatever) and flash (SD card - NAND Flash - ... whatever). My MCU ...
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1answer
97 views

Cortex M3 debugging: Intermittent partial load of binary with pyOCD, then timeout

I'm debugging an embedded system and get intermittent binary loading errors when flashing the binary through gdb (well, arm-none-eabi-gdb, the toolchain gdb client). Here are the details of my setup: ...
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1answer
268 views

how to make a phase shift on PWMs

I want to generate 2 PWM on PC6 & PC7 on an STM32f10x , it work fine but , the problem that I have is that I want to make them phase shifted to each other , say 45° and I really don't how to do ...
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2answers
1k views

setting the frequency of a PWM on a STM32

I'm trying to write a function that takes a desired frequency of PWM and sets the timer based on this value: ...
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2answers
2k views

STM32F103 GPIO not working

I am programming for LPC microcontrollers (mostly LPC1769), for the past few months with success. I decided though to give STM32 series a try. I just received a no-name board using an STM32F103C8 MCU ...
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1k views

STM32 USB Library - transmit fails with specific data lengths?

I am implementing USB communications on a STM32F107, using ST's USB Library v2.1.0. It communicates as a CDC class Virtual COM Port ("VCP"). I'm using the embedded Full Speed PHY. I've started with ...
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1answer
117 views

Flash memory read and write

I'm always disabling interrupts while writing to some sectors on Flash, but does Flash memory requires disabled interrupts even when you just want to read from it? Why yes and why not? Thanks for the ...
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1answer
140 views

Are unaligned LDRH/STRH supported on Cortex M3/M0?

Can all Cortex M0/M3 cores do this? LDRH r0, [0x8001] This would suggest yes but I don't see anything specific about Cortex-M cores.
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349 views

Sram in the ARM cortex m3

I load a project into the chip STM32f103ZC whose internal sram is 48kBytes , there are also 2MBytes external sram on the board. But when I download and debug the project,the map file tells that ...
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58 views

Calculating processor utilisation

I'm using a Cortex M3 processor on an LPC1769 board. For this particular situation, all processes occur within interrupts. Therefore, within the main "loop" there isn't actually anything to be ...
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3answers
91 views

Will XORing the FIO0PIN register on an LPC175x6x give unexpected results?

Is this code guaranteed to only effect pin 22? int* FIO0PIN = (int*)0x2009C014; *FIO0PIN ^= (1<<22); At first it seems like a dumb question but I remember ...
2
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1answer
323 views

How to use level-triggered interrupts with STM32F1xx?

I'm getting conflicting info on whether I can use level-triggered (as opposed to edge-triggered) interrupts with the STM32F1xx microcontroller. In ST's CMSIS-compliant Standard Peripheral Libraries, ...
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0answers
124 views

Strange behaviour using PWM on CortexM3

I have a board with the ATSAM3S2BA-AU, which is a Cortex M3 uC. I need to use 2 PWM channel , here how I've done it : ...
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1answer
232 views

Trouble holding MCLR line low for PIC ICSP, ICD3 works, hardware defect?

I have an ARM Cortex-M3 that talks to a dsPic33F. I am attempting to do ICSP programming of the attached PIC. I have an analyzer and can see that I cannot control the MCLR line the same way the ICD3 ...
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1answer
89 views

Will the ADC work with resistive inputs in LPC1796

I'm working with LPC1796 and I have to do data acquisition for my project somebody told me that LPC1796 microcontroller won't work with resistive inputs. What is a resistive input? Is there any way ...
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2answers
55 views

Why doesn't the MCU's pin go high on time?

I have a STM32F103 and I downloaded this program to it(a simple blink program): ...
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2answers
3k views

STM32F103, Having trouble nesting interrupts

I'm trying to interrupt into a USART handler from inside an RTC_Alarm handler, but it doesn't work. I have set the NVIC: ...
2
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1answer
113 views

Basic idea of color look up table

I'm driving an ILI9230 LCD 320*240 16bit interface, with a framebuffer of 250*200 and I want to drive it as 4bit. so I built a loook up color table like that: ...
2
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1answer
569 views

STM32F10x SPI - No Clock

I'm trying to get basic SPI operation working on an STM32F107VC chip using the WaveShare Port107 development board. I'm trying to initialise SPI1 which resides on PA4-PA7. I'm attempting a simple ...
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1answer
557 views

What's the concept of these three options for configuring the memory of STM32?

I have read the STM32F10x Reference manual but a section about "Reading the Flash memory" is not clear to me, yet. I mean this part(page 59): I have several question: What's the Latency? in fact ...
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0answers
167 views

Choosing Cortex M3 for beginners [closed]

I looked at this thread already - "How to choose an ARM Cortex M3 microcontroller" However, my question is a bit a different. I want to focus on more of a learner/beginner's perspective. As the ...
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1answer
441 views

Porting Linux drivers specifically I2C

I am developing an I2C driver for an accelerometer. My objectives (actually it's the restriction I have as per the project guidelines given in my institute): use Linux flavour of operating systems ...
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1answer
334 views

Cortex M3 GPIO Interrupt won't trigger

I have set a pin on a Cortex M3 to act as an rising-edge triggered interrupt and it's not firing for some reason. What it should do is receive a 1Hz pulse, trigger an interrupt and start a 12.8Khz ...
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1answer
2k views

TCP/IP stack library for ST microcontroller

I'm looking for a free function library, that implements TCP/IP stack for STM32F103CBT7 (Cortex M3) microcontroller. The datasheet of this controller is following: http://www.farnell.com/datasheets/...
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3answers
722 views

Is there any difference between the assembly instructions of ARM MCUs from two different corporations?

I'm curious to know, are there any differences between the assembly instructions of ARM MCUs from two different corporation? For example between an Cortex-M3/4 of NXP and TI or ST or other ...
2
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3answers
1k views

How fast can ARM Cortex M0s/M3s bit bang?

I have not yet used ARM Cortex uCs, only AVRs Firstly, how fast can they: Stream 1024+ bits (serially, from bytes in RAM) out of a pin, with no pauses/jitter Stream 1024+ bytes (parallel, from RAM) ...
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500 views

Force Cortex-M3/4 reset from assembly

I would like to force my STM32F4 to reset on fault, I tried to copy NVIC_SystemReset in assembly as : ...
2
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0answers
292 views

Atmel Studio JTAG Debugger Behaviour

The qeustion: I would like to know what is different about the way JTAG treats the "step over" and "step into" commands. Background: I am trying to set a GPNVM bit on a SAM3N (ARM Cortex M3) chip ...
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2answers
179 views

Task switching on Cortext-M3 crashes after IRQ

I've used an exokernel model for my ARM OS. When a task wants to read from a UART it calls a library function, which, if there's no data, makes a SVC call to block the task (which causes the kernel to ...
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1answer
751 views

Is it possible to control a 4 wire Bipolar stepper motor with a PWM signal?

I am trying to control a 4 wire bipolar stepper with a PWM signal being output from a VEX cortex controller. I am planning on using 4 bipolar NEMA 17 12v steppers to drive a small remote controlled ...
2
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2answers
942 views

The GCC Ride7 STM32 startup script does not jump into SystemInit function

We are a robotics association from ENSEIRB-MATMECA (Bordeaux, France). We are developping some boards and a template project for STM32 devices. One of our boards embed a STM32F103C4 microcontroller. ...
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1answer
458 views

If a controller has MPU, will it run Linux efficiently?

I have an EFM32 board having Cortex M3. This board is having an Memory Protection Unit. Will it be a good idea to port Linux on it? I am discouraged because of this answer: Linux on ARM Cortex-M3 ...
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3answers
6k views

Laying out a 10-pin JTAG/SWD connector on a final design

I'm designing a board with an ARM microcontroller on it (LPC1347FBD48) and I want to include a 10 pin jtag/swd connector, as is standard, for in-circuit debugging of my final design. Here is the ...
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3answers
2k views

Cortex M3 delay 1us

Im trying to achieve 1us delay to be able to drive 1-wire bus. My proc is working on 10Mhz PCLK so I tried to use timer function with overflow on 10th cycle. For some reason it gives me resolution of ...
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2answers
638 views

LPC1788 reading via SPI from ENC28J60

I have a problem with SPI communication with ENC28J60 chip. Basically I can't use SSP in SPI mode as it is, because ENC28J60 expects CS to be low for multiple bytes while SSP shifts it high after each ...
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3answers
10k views

Any ARM based microcontroller with integrated WiFi? [closed]

I am looking for a ARM based low cost SoC with an integrated WiFi, tried different search engines and still not been able to locate one. I would like to know if anyone knows of such device that has ...