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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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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27 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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27 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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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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39 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
103 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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204 views
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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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78 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
53 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
53 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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1answer
70 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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96 views
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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
40 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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124 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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1answer
129 views

STM32 SPI half duplex (1-wire Bidirectional) problem

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
72 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
62 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
64 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
119 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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88 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
162 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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81 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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1answer
94 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
147 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 ...
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1answer
103 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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84 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
114 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
129 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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104 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
46 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
93 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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100 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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104 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
172 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, ...
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81 views

STM32F2 code execution problem -solved

I just got into using STM32F2 microcontrollers. However, I am unable to get the micro work. I have a board designed by my own, with only the microcontroller, power supply capacitors, 2 leds and a UART ...
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1answer
283 views

STM32F103 simple countdown timer (with no interrupts)

I'm trying to create a simple countdown timer (without using interrupts) - to use to check for timeout while waiting for an external event to occur. Ideally, I'd like to preload a timer counter with ...
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1answer
71 views

STM32F4xx input pin reads wrong state on first run but not subsequent

I am working on a program which reads the state of a pin at startup to determine an operational mode. When I run the code on first power up, it reads incorrectly, but subsequent resets without power ...
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1answer
78 views

STM32F102 USB Programming

I am currently designing a board for a STM32F102 chip which needs to be able to use the USB bus to transfer data while the chip is running. However I also want to be able to program the chip through ...
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33 views

Eclipse Template for STM32L

Where can I find additional templates for the ARM-GDB debugger for eclipse? Otherwise, how do I create a template and which variables would change from the STM32F series and the L series? Thanks
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1answer
191 views

STM32F103 Systick Interrupt stopped working when debugging in ram - (Coocox IDE)

I tried debugging my code in ram in order to increase the flash's life (only rated at 10k writes minimum) Anyways, I have tied the boot0 and boot1 pins to 3.3v and set the compiler to debug from ram ...
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2answers
322 views

Independent watchdog (IWDG) or Window watchdog (WWDG)?

I'm still searching to find an answer for this question: Why while the stm32 MCUs have a perfect watchdog (I mean Window watchdog (WWDG)), there is a simple watchdog (Independent watchdog (IWDG)) ? ...
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1answer
157 views

STM32F103 strange behavior

I'm working with an STM32F103 device and am experiencing some strange behavior that I'm not so sure about where start with when it comes to debugging it. I previously asked a question regarding DMA ...
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1answer
51 views

The same flag for an interrupt

I think I'm mixed up a bit in NVIC of stm32 MCUs. I took a look in the SPI.h of the STM32F10x standard peripheral library. I don't know that why while there is ...
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68 views

USB in Nucleo F302R8

I'm using the Nucleo F302R8 to build the firmware for a new board I'll develop using the same MCU. I'm trying to use USB CDC to have a VCP. I've started with CubeMX with the Nucleo F302R8 template, ...
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1answer
191 views

STM32F1 Can't I use the internal voltage reference as the ADC reference?

There seems to be a badgap voltage reference built-in in the STM32F1 microcontrollers (on ADCx_IN17). Coming from AVRs it seems to me very strange that it's not possible to use this reference as the ...
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1answer
187 views

What USB class should I implement?

I'm playing around with STM32F4 Discovery board and libopencm3. I want to send data acquired from ADC channels over usb and display some charts on the computer. After doing some research on USB class ...
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277 views

SPI1 doesn't work

I'm working on a simple project. I want to send a string. the string is "Rohalamin". the second board after recieve the string should turn on the LED. the program for first board is (the MCU for ...
2
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1answer
171 views

jpeg images in STM32 internal flash

I'm using both STM32F103 and STM32F407 with a SEPS525 SPI driven OLED display (160x128). I want to store images to display in internal flash, but BMP uncompressed images with 16bit colors are huge ...
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77 views

GPIO control of alternate function pin

I have an STM32F4discovery and using a pin as SPI CLK. But I also want to be able to control the pin as GPIO to generate ANY frequency I want (STM32 only lets you prescale APB clock). How can I ...
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247 views

Is it possible to program an STM32 with an Arduino?

I have one of these: http://www.ebay.com/itm/111297094334?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649 I know an USB-TLL dongle is usually used to program it, but I don't have one and I ...