I am working on a project and i ran out of I/O pin so, therefore, i would like to know how the reset pin can be used as an input/output pin.
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I have high voltage programmer as well. I wrote the code in Arduino IDE and then used it's hex file to program it using high voltage programmer (TNM PROGRAMMER).
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I'm trying to connect to stm32f401rbt6 with st-link utility.
The MCU has 6 pins connected, as on the image below.
The target is powered by a lab power supply, target GND is connected to the ST-Link GND
When I plug it to the computer, st-link utility says it can't connect.
Tried:
Update ST-Link firmware
Connect under reset is by default, tried all available methods
Checked connectivity for the pins on the image
Connected with the same ST-Link to other MCU
Desoldered the MCU and soldered another one
The issue is still remain. Please suggest what I'm doing wrong, or how to check that my MCU is alive.
I once had similiar issues and i figuered out, that decoupling capacitors were vital. After soldering this onto the pcb, it worked like a charm.
(Similar question: Stm32CubeProgrammer not connecting (no error msg) using ST-LINK V2 dongle and Lora E5 mini board)
You can try the following suggestions. Some ST devices are a lot more sensitive than others when it comes to programming. I have had some ST devices programming without issues and then using practically the same setup on other devices it just won't work.
Place a 22ohm resistor in series on the SWDIO and SWCLK lines. This link suggests only placing it on the SWDIO line but I found that I needed it on the SWCLK line as well. Typical SWD Circuit
For the ST Link Settings try using these:
Reduce the frequency from 4MHz to a lower frequency
Use SWD
Use connect under reset
Don't use an external pull-up on the NRST line.
Make sure that your programming wires between the ST-LINK and the target board are as short as is conveniently possible.
(This one I must stress as being important) Make sure that your processor's ground pins are all connected very closely together (i.e. the tracks between them are as short as possible) and that very importantly your programmer ground is also connected to the same ground pins very closely.- At high programming speeds a thin or long unbalanced (different length) ground track to the processor can cause a problem with some devices.
Whatever you are using to supply power to the processor must have a supply with a similar voltage as the ST-LINK (mine is 3V) - (although I have found that if the processor supply is 3.3V programming seems to still work most of the time.) (Remember the original ST-Link does not supply power only reads the power level.)
A dodgy programming setup can accidentally set the protection to LEVEL 2 bricking your device - so if you have been trying and not getting any further, it might be time to replace your IC.
Prior to changing / erasing a device that had been programmed to LEVEL 1, you might need to first enable the PCROP_RDP option byte. - Once enabled, you should be able to change from LEVEL 1 to LEVEL 0 that will automatically erase the device.
Some people have suggested holding the device in reset until just after pressing the erase button to enable erasing it.
I hope these suggestions help...
the atmega microcontrollers have the internal programmable memory.So the usb flash device write data to internal memory of atmega through spi or it store the program and works as slave?i also want to know can the atmega get program,file in the MicroSD and run without internal memory or it need to run a program in internal disk then including the program in MicroSD?i don't know how the process work in atmega microcontroller.
There are several ways to program the AVR:
Using an external programmer. The Chip is in reset state during this. Then the programmer uses special a special protocol to directly write to the flash inside the controller. This is how your USB programming device probably writes code to the AVR. There are several protocols for this, but the most common one uses the same pins that are used by SPI. You should not confuse them just because of that ;-).
The controller writes the program itself. The chip is actively executing a program. That program on the chip fetches the instructions from e.g. a sd card and using the SPM instruction to copy it to local flash.
The AVR can only fetch instructions from it's own flash memory - you cannot execute directly from RAM or from any other external source.
The best answer for this question you can find at the end or middle of datasheet for AVR device (eg ATMEGA 328P-PU). If you are using some flashing device connected with computer, there is some initialization sequence after start and then there are send some 4 Bytes commands that tels microcontrolers, where to store values to flash and/or eeprom, fuse bits, or cares about erasing etc. There is also posible to read ID of chip.
Atmega microcontroler can be also programmed in paralel mode, where are some bits used for sending commands that tels, what to do with data on data bit.
If you ask about downloading program from SD card or any other device, there is possible to write to the flash through SPM, as there was told above. Some devices do not have part of flash for downloader - if I remember ATMEGA 48, and devices, that have configurable part of memory usable also for downloader, that can handle this, eg. ATMEGA 88, 168, 328. So if you want to download program from SPI, USART, TWI, etc, you need to configure fuse bits and create downloader that will do it for you. I am not sure, how ATMEGA 48 do this, but there si probably possible to write whole flash by SPM instruction.
However the best answer you can find in the datasheet. On pages folowing 255 you can find further information. http://www.atmel.com/images/Atmel-8271-8-bit-AVR-Microcontroller-ATmega48A-48PA-88A-88PA-168A-168PA-328-328P_datasheet_Complete.pdf
I'm using a USB-6356 DAQ board to control an IC via SPI.
I'm using parts of the NI SPI Digital Waveform library to create the digital waveform, then a small wrapper VI to transmit the code.
My IC measures temperature on an RTD, and currently the controlling VI has a 'push for single measurement' style button.
When I push it, the temperature is returned by a series of other VIs running the SPI communication.
After some number of pushes (clicking the button very quickly makes this happen more quickly in time, but not necessarily in number of clicks), the VI generates an error -200361, which is nominally FIFO buffer overflow on the DAQ board.
It's unclear to me if that could actually be the cause of the problem, but I don't think so...
An NI guide describing this error for USB-600{0,8,9} devices looks promising, but following the suggestions didn't help me. I substituted 'DI.UsbXferReqCount' for the analog equivalent, since my read task is digital. Reading the default returned 4, so I changed the property to write and selected '1', but this made no difference.
I tried uninstalling the DAQ board using the Device Manager, unplugging and replugging, but this also didn't change anything.
My guess is that additional clock samples are generated after the end of the 'Finite Samples' part for the Read and Write tasks, and that these might be adding blank data that overflows, but the temperatures returned don't indicate strange data, and I'd have assumed that if this were the case, my VIs would be unable to interpret the data read in as the correct temperature.
I've attached an image of the block diagram for the Transmit VI I'm using, but actually getting it to run would require an entire library of VIs.
The controlling VI is attached to a nearly identical forum post at NI forums.
I think USB-6356 don't have output buffers used for Digital signal. You can try it by NI-MAX, if you select the digital output, you may find that there is no parameters for Samples. It's only output a bool-value(0 or 1) in one time.
You can also use DAQ Assistant in LabVIEW, when you config Digital output, if you select N-Samples or Continuous samples, then push OK button, here comes a Dialog that tell you there is no buffer for lines that you selected.
OK, so I have a 3 pin 315/433MHz rf reader module which I've connected to my raspberry pi 2. 2 pins are for Voltage and ground, and 3rd goes to a GPIO pin configured as input.
I've actually gotten all of this to work just fine. I can read data manually from the GPIO pin just fine, by accessing the file
/sys/class/gpio/gpio23/value
I can even place a car key next to the receiver press a button, and see the values change between 0 and 1.
The problem is that I cannot figure out how to read the clock, so I cannot figure out if there are supposed to be multiple ones or zeros in a row in the data its reading. There doesn't seem to be any time stamp that I can find to see when the last value was read.
How can I properly read the data the module is receiving?
There are two common protocols used for 315/434 MHz radio transmission by hobbyists (that I know of).
Keyfob type remote control devices tend to use Manchester Encoding.
General data transmission using the Virtual Wire protocol (as popular with Arduinos).
My pigpio library has a Python Virtual Wire implementation and C/Python keyfob Manchester Encoding example (for receive and transmit).
your RF reader should be outputting serial data at some known baud rate (check the manual?) assuming you haven't wired it up to the dedicated serial pins you could look at using the pigpio library, more specifically the bit banging serial commands here for python or here for C/C++ or here for pipes
This allows you to use any GPIO pin for reading serial data and the library has bindings for several methods of use as shown in the links above.
I have a microprocessor with the card's chip select (CS) line tied to a 'frame' signal automatically driven by the SPI (SSP) circuit. This causes CS to go high between each byte.
The MMC/SD specs require that CS be held low in order to enter SPI mode. Does it need to be held low the entire time, or only when transmitting each byte of CMD0?
At the sdcard.org site, I found various PDF specifications for SDIO. None of these seem to have an explicit timing statement which clarifies this. However, this statement does occur:
(1) SD Bus mode is selected by CMD0 (Keep Pin 1 to high during CMD0 execution).
from page 88 of SD Host Controller Simplified Specification Version 2.00. ("Pin 1" is Chip Select (CS))
Given that sentence, an SD card manufacturer would be justified in requiring that you assert CS through the entire D0..D15 bits being sent. In other words, I think you cannot use the SPI frame signal and will need a GPIO pin or similar.