I want to store information in sdhc memory using stm32. But the f_mount command always returns FR_NOT_READY.
But when using sdsc memories (less than 2G), the code works correctly.
My microcontroller is stm32H743iit6
All sdsc memorty card (2GB) work correctly.
Related
I am writing an operating system for the raspberry pi.
I have a problem with the sdcard driver for the custom sdhost controller (emmc2)
of the raspberry-pi 4 (Cortex-A72, ARMv8-A, bcm2711 chipset).
Without using sdma everything works. With sdma, read works, but after writing sectors, the data on the sdcard sometimes contains invalid data.
For the sdma data transfer, I use a transfer buffer with a device type memory attribute (nGnRnE). When I use a fresh data buffer for the dma write transfer, the data on the sdcard is correct. But when I reuse the same buffer for the next write, then the sector on the sdcard partially contains data from the previous buffer content.
Maybe this is a cache coherency problem. I have enabled all caches (I and D). In the ARM manuals there is a talk of the SCU (snoop control unit) and I don't know whether I have do bother about the SCU.
My questions are:
Is it necessary to enable the SCU on a Cortex-A72 and how can this be done ?
What other things have to be kept in mind when using dma for device access ?
I found the solution for my problem:
On the raspberry pi 4 (bcm2711 chip), the physical addresses that are written into the registers of a dma engine must be legacy master addresses. The legacy master addresses are in the range 0xC0000000-0xFFFFFFFF. So I have to add 0xC0000000 to the values of the physical addresses that are written into the registers of the sdhci controller.
The documentation can be found here:
https://datasheets.raspberrypi.org/bcm2711/bcm2711-peripherals.pdf
1.2. Address map
1.2.4. Legacy master addresses
The answer to the other SCU question is: it is not necessary to enable the SCU on the Raspberry Pi 4 when the caches are enabled.
I'm just creating an app(kivy) for a raspberry pi(3b) with 7 inch touchdisplay. In addition I implemented a light sensor (TSL2591), which can regulate the brightness of the backlight using following command:
os.system('sudo sh -c "echo '+str(brightness)+' > /sys/class/backlight/rpi_backlight/brightness"')
with values of brightness 0 to 255
Works fine so far, but I do update the brightness once a second. If I'm not wrong, the command overwrites a config file and I mind of write access to the SD Card that often. I think the SD card will be corrupt after a short period of time.
For sure I can try to get less write operations, but it also leads to less smoothness:
update slower than 1 sec
only write if brightness value really changes
don't use all of the 255 steps
So the main question is: is there any other way to control the brightness? Or any workaround? I could not find a "real" Datasheet or any other advice on the internet. So maybe there is another way.
That's not a conventional disk file; it's a "device special file" which the kernel artificially creates to look like a disk file. It allows you to "talk" to device drivers using standard read() and write() calls.
You need not worry about SD card wear.
For a fast ADC sampling USB device, I am using the USB 2.0 High Speed capable STM32F733 with the embedded USB-HS PHY. In USBView, I can see that the device is enumerated, the libusb code opens the device and claims interface, but when I try to receive data with libusb_bulk_transfer, the operation times out (return code -12). Things I have tried: I have confirmed than when I request data with libusb_bulk_transfer, the device is interrupted. Note: I have DMA enabled in my class configuration C file and it is not clear to me how that is triggered. I have verified that the transfersize and packet count registers are being set correctly by the LL library function, and that when I request data from
Any tips on debugging such problems will be much appreciated - this board is my undergrad thesis due in under two months!
Desktop sequence:
libusb_get_device_list, libusb_get_device_descriptor, libusb_open, libusb_get_string_descriptor_ascii, libusb_free_device_list, libusb_bulk_transfer(devh, fat_EPIN_ADDR, inframe, fat_EPIN_SIZE, &gotBytes, 100). Where gotBytes is integer, and inframe is a large array.
Device firmware:
MX_USB_DEVICE_Init();
uint8_t txBuffer[10*fat_EPIN_SIZE];
while (1)
{
USBD_LL_Transmit(&hUsbDeviceHS, Custom_fat_EPIN_ADDR, txBuffer, Custom_fat_EPIN_SIZE);
HAL_Delay(1);
}
Custom_fat_EPIN_SIZE is 0x200 and the endpoint address is 0x81 (EP IN 1)
Installed driver for device is WinUSB (verified in Device Manger to be winusb.sys), and I am linking libusb-1.0 into my desktop program. You can find my source code at https://gitlab.com/tywonemi-school-stuff/silicon-radar-fun, the firmware is My SW/v1 and the desktop software is a Qt Creator project in My SW/Viewer, of note is usb.cpp. You can also compare with testing project/HIDTest, which is code that I tested with STM32F303 nucleo dev board where I was able to read an array through IN bulk endpoint with the Viewer application. However, F3 has the USB peripheral, while F7 has OTG_USB, and I am now attempting USB 2.0 compliant HS so there may be more protocol-based pitfalls. You can also find the output of the device descriptor etc from USBView in my SW/USBView_broken.txt
EDIT 1: I have found finally some concrete error in the STM32 behavior. The DMAADDR is set for EPIN 0x81, and never increments, despite the DMA being enabled. I have went through literally every occurrence of the word "DMA" in the USB_OTG periphery.
I thought it might be that my linker script makes my array be stored in DTCM or similar, and the OTG DMA can't access it, but the address of txBuffer is 0x2003EBEC which is in SRAM2. The AHB matrix in the reference manual clearly shows, that the USB OTG HS DMA is master for a bus that SRAM2 is a slave of. And DTCM is connected too. I will look for application notes for USB OTG HS DMA - it just seems to be refusing to copy data!
I have fixed my issue by disabling the DMA setting. I have re-read the relevant portions of the reference manual and still don't know how exactly the values propagate into the Tx FIFOs. It is possible that DMA-less operation will be a major bottleneck in my project, I might return to this later.
I have multiple 512MB SDSC cards that seem to block after getting a read single block command. I get back the expected data which I wrote before, but the card seems to stop returning anything but 0xFF afterwards. Even simple commands like CMD13 (request status) do not send back anything but 0xFF. While these commands did return normal before the read command was used.
The entire code does work with another SDHC card. Attempting reinitialization does not work until the card has had its power removed. I am using SPI mode.
I am running out of ideas what the issue might be.
The addressing scheme for SDHC and SDSC is slightly different: SDHC requires SECTOR id while SDSC needs BYTE address. Maybe that's the case with CMD17.
What is the Difference between BGAPI and BGScript ?
And if we write any code for BG profile than how can we burn it in BLE 112?
The BGAPI interface defines the protocol used to talk to the module over USB or serial link.
BGScript is something which runs on the module processor itself, when the USB or serial link is not used.
I have the dongle, BLED112, which is the same thing as BLE112 with a USB connector on it, and the code is "burned" to it using standard USB DFU interface.
The downloading of the code to BLE112 can be done using several methods:
(1) Bring out the DD, DC debug interface pins from your module and use the CC-Debugger (digikey part 296-30207-ND, $55). This works every time. If you have the DKBLE112 kit, the CC-Debugger fits on the 10-pin .050 connector in lower right corner. You can "burn" any firmware and any stack this way. Works awesome.
(2) Hope that the current firmware on the CC2540 has serial bootloader, and load the new firmware (hopefully also containing serial bootloader) using UART. TI has the tools, but it sure seems quite convoluted to me, and I did not try it.