The STM32 is the third ARM family by STMicroelectronics. It follows their earlier STR9 family based on the ARM9E core, and STR7 family based on the ARM7TDMI core.

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Cannot change DMA configuration after first transfer

I'm using a stm32f10x microcontroller and I'm trying to program its DMA module for normal mode transfers. The first transfer works perfectly, but after it's over, I try to change the source, ...
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49 views

Real time tasks with CooOs

i am using CooOs with 4 tasks.the problem is that only the first task run (indefinetly).What i want to do is to toggle each task 3 seconds then switch to the other.I know that i can do that with ...
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37 views

How to configure Coide to use DSP library for STM32f3?

I am struggling to use the DSP library provided by ST for my STM32f3 discovery board. I am using Coide. I started by including arm_math.h since all the DSP library files refer to it. I am getting ...
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37 views

USB Busy when transmiting data

WHat should I do when I am sending data using USB, when the callback in my firmware gives me USB BUSY? Once, I received USB Busy state, I could no longer send data to my host from my firmware, but my ...
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45 views

STM VCP USB_BUSY?

I am using STM32 VCP firmware, and I am sending data to my PC application If i did not open my serial port in PC, and my firmware keep on sending the data it will cause USB_BUSY to happen, (i think ...
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36 views

STM32F4xx - Can EXTI_GenerateSWInterrupt() Wake Up Processor from Stop Mode

As the title states, can the function EXTI_GenerateSWInterrupt() wake up the processor after it is put into a low-power mode using the PWR_EnterSTOPMode() function? The documentation says that an ...
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69 views

CAN bus acknowledgment error

I am using an STM32F429 CAN bus program with TJA1041A as the CAN transceiver. The problem is that the messages are not getting acknowledged, and herewith I am attaching the code for further reference. ...
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39 views

What is the difference between write and flash

My apologies for my very naive question. I am trying to get some understanding of the STM32 bootloader, specifically I am looking at stm32flash where I read: write to flash/ram read from ...
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70 views

Update STM32 firmware via Android [closed]

Sorry for the very open question, but I really know nothing about EE. I am an Android developer, I have been asked to create an Android application to update the firmware of a STM32 microcontroller. ...
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40 views

stm32f0 USB keyboard LED controlling with DataOut or RxReady0 with endpoint 0

I am making a USB keyboard using stm32F0RBT6 micro-controller. I want to receive data from PC for Caps Lock and Scroll Lock leds. Do I need to initiate a callback funtion like those ones? ...
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1answer
86 views

STM32F429 / STM32F439 read-while-write from two memory banks. Prevents stalling CPU?

I have been reading up on the STM32F429 flash memory (2MB version). From the STM32F4 reference manual I found out that it has two memory banks and supports read-while-write (RWW), which means it can ...
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1answer
43 views

Flash memory range on STM32F429II

I am reading the STM32F429II data sheet and looking at page 84, which shows the memory mapping. The chip has 2MB of internal flash memory, but the data sheet is general for all STM32F427xx/STM32F429xx ...
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2answers
123 views

STM32F4 FSMC 8-bit data width with 10+ bit addressing

I'm planning to interface an FPGA to a STM32F29/439 via the FSMC (Flexible Static Memory Controller). To save pins I would like to use the address/data multiplexing feature. Thus according to the ...
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1answer
40 views

How to attach/interface an ARM Cortex SoC with an stm32 processor

I'm trying to work out the best way to attach / interface an stm32f processor with a Linux based ARM SoC? Is it possible for the stm32 to communicate with the ARM SoC via I2C ...are there any ...
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170 views

STM32F4 NAND flash via FSMC, difference between bytes written and read back

I have a Waveshare Open407V-D development board, basically a "motherboard" in which an STM32F4DISCOVERY kit is fitted (this kit, for those not familiar with it, is made by ST itself and based on the ...
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1answer
93 views

Guitar Pre-Amp stage/filtering and STM32F4

I am currently involved in an academic project which the topic is to design a Digital Tuner for Electric Guitars. My knowledge of electronic is very basic, so here I am. I need to pre-process the ...
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89 views

STM32 ADC: Multiple channels with different sampling rates

I am trying to figure out how the STM32 multiple channels ADC conversion works (regular group). Lets say I want to convert on two channels, channel 1 and channel 2, on ADC1 and the sampling rates are ...
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113 views

STM32 - Multiple channel PWM input

I am using an STM32F405 based board , (OpenPilot revo ) to receive PWM signals from a joystick receiver . i have to xapture 5 PWM signals using only two timers , the timer 8 and the timer 12 . I've ...
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65 views

STM VCP Driver .inf file

Where can I get the STM32 Virtual Com Port (VCP) Driver .inf file? I want to configure the driver to change the Latency Timer and Receive/Transmit buffer size, but I cant find it. I also cannot ...
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270 views

Why does ST recommend 100nF decoupling caps for a 72MHz MCU? (And not 10nF)

I've been reading about decoupling caps, and I can't seem to understand why ST recommends 100nF decoupling caps on a 72MHz arm mcu. Usually 100nF decoupling caps are only effective up to about ...
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91 views

USB termination on STM32F437xx

I'm about to layout the USB connection on our boards and wondering whether the termination resistors and pull-up on D+ are necessary when using the STM32F437xx. The datasheet tells: ...
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1answer
205 views

Why use STM32 HSE?

Why do we use an external oscillator for STM32??? Why not just use the microchip oscillator? I am using STM32F2xx it clocks at 120Mhz But, an external oscillator of 12Mhz is latch into the ...
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2answers
236 views

Weird oscilloscope readings with a digital signal (ws2812)

Pretty new to oscilloscopes. I'm trying to learn stm32, so one of the projects I'm working on is getting ws2812 LEDS working on stm32. It does work for most strips, however, there are few strips ...
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1answer
195 views

STM32F4 Timer accuracy

I'm working with an STM32F4 Discovery board and I've come across a bit of unusual behavior that I'm hoping someone can explain the cause of to me. My goal is to configure a timer to trigger an ...
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1answer
154 views

STM32 USB: detecting connection and disconnection

Using STM32F4 USB Mass Storage Controller example in Device Mode, how do you detect connections and disconnections with a host controller? I tried polling the VBUS pin state yet it could be high from ...
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1answer
63 views

What does the “OPT” build target stand for?

When exploring the example projects, I've noticed that the regular Blinky project has 3 targets. I think I understand what Flash and RAM stand for (it's all a bit confusing), but I haven't seen ...
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94 views

What does ADCXX_INYY represent? Configuring ADC on certain pins from STM32F207ZG Board

I have a STM32F207ZG-SK board, and I want to configure pin B0 and A6 to read analog values from another board. Did I do the setup for pin B0 and A6 correctly? I checked to see if it has ADC and it ...
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1answer
118 views

STM32 PWM only works correctly when I leave in two unused variables: StartUpCounter and HSEStatus

I'm using the stm32f3discovery board to try and generate the signal for a ws2812 light strip. I've got src/system_stm32f30x.c, which I copied from the StdPeriph ...
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1answer
73 views

LPC43xx External Static Memory - Multiplexing of Address/Data lines

We would like to tightly-couple a FPGA with a µC by means of the external static memory memory controller, thereby effectively mapping the FPGA registers into main memory of the µC with maximum ...
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309 views

STM32 USART with DMA — which interrupts to use?

I'm working on firmware for an STM32F103 which is communicating over RS232 at 115200 baud with a motor controller. The motor controller (a Copley Xenus XTL) operates on a "speak when spoken to" ...
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2answers
289 views

STM32 SPI half duplex (1-wire Bidirectional) problem

Update: see my answer for fix. I'm trying to read 4 byte from a SPI-compatible slave (MAX31855) in 1-wire bidirectonal SPI half-duplex. Here is my code [SW Controlled SS] [SO->MOSI] ...
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1answer
113 views

SPI Interrupt Handler delay in STM32F303?

I'm working with an STM32F303 microcontroller configured in slave mode running at 72 MHz, and I've come across some strange behavior that I'm trying to track the origin of. The master first sends ...
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1answer
150 views

How to flash protected STM8/STM32 MCU?

I would like to flash a new firmware on my STM8L15xC8. I have ST Visual Programmer (STVP) installed and can successfully flash the MCU of the STM8 Discovery board. Now, I setup the STM8 Discovery ...
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1answer
102 views

STM32F2xx: Data from SPI Slave to Master

I have a STM32F2xx connected to a FTDI UM232H using SPI, STM32F2xx will be configured as SLAVE and FTDI will be configured as MASTER My scenario is this, I am getting data in STM32F2xx, and when I ...
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2answers
247 views

Understanding SPI

I have some problems understanding SPI: I am currently using STMF2xx to connect with FTDI UM232H, I will configure my STMF2xx into slave and FTDI into master. But, I am having problem getting the ...
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143 views

RTC DS1307 3.3V I2C and Oscilloscope impedance

I'm working on a library for STM32 to learn I2C protocol (Software I2C, not hardware). I connect my DS1307 (Sparkfun BOB-12708) : (Here is the module schematic) : I remove welding on the SJ2 jumper ...
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2answers
325 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: ...
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165 views

STM32F030 RTC wakeup from stop mode

I'm writing an app, that most of its time will spend in STOP or STANDBY mode (battery powered microsystem). I'd like the internal RTC to wakeup my STM32 every 5 minutes, enter the ISR, do its tasks in ...
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95 views

Why does my MCU go back? (to the previous instruction)

I don't know why but I see the same odd behaviour sometimes in the debugger environment. Look at this code (function): ...
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1answer
396 views

Full duplex SPI Master using DMA - STM32F105

I'm trying to write a SPI driver for an STM32F105, using DMA functionality. I'm using ST's Standard Peripheral Library. I'm not using interrupts. I can talk to the destination device if I use standard ...
2
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1answer
158 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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2answers
124 views

STM32F103 - TIM5 doesn't exist on medium density devices ? How do I tell what else is missing?

I've tried setting TIM5 as a timebase timer with an interrupt, when the compiler gave me the following error: 39: error: 'TIM5_IRQn' undeclared (first use in this function) Than I though I'll ...
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1answer
190 views

STM32F1 troubles with a timer

I'm having some troubles with setting up a 1 second timer on STM32F103 mcu. I have set Timer 2 to have a prescaler of 1099 and a period of 65514, so I'm expecting to have a 1 second interrupt rate: ...
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1answer
228 views

PDM to PCM conversion workload on 32-bit micro (such as STM32)

Can anyone provide a rough estimate of the processing power required to do PDM (e.g. audio from MEMS microphone) to PCM conversion on a 32-bit microcontroller ? Specifically - I see ST provides a PDM ...
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176 views

SPI TX Error on STM32F4xx

I have tried posting this question on the ST forums but have not seen any traffic on it so I figured I would try here. Background STM32F407IGT processors SPI2 peripheral being serviced by DMA ...
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1answer
51 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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3answers
119 views

What is SPI Interrupt (SPIE) in SPI control register?

I have been trying to understand SPI Interrupt i.e. what does it do and why is it used ? Reading about it on the web has not helped me. Can some one please explain it in a simple terms ?
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1answer
152 views

Unable to read file greater than 2K in FatFS

I am reading a file from the SPI Flash with FATFS file system, on STM32F103 platform running FreeRTOS. I can successfully read File of size less the 2048, but if read a file file of size greater than ...
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162 views

STM32 ADC sampling problem

I'm using the STM32F2 microcontroller, and have a weird problem with the ADC. Seems like the ADC sampling circuit needs a reset to take a sample, as the ADC value quickly drops after the reset. For ...
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1answer
274 views

USB interface with STM32

I'm experimenting with native USB in STM32. I've not found any "step by step", or a little more well structured tutorial, how to implement CDC or mass storage for example. I've found some examples, ...