I have Windows IoT Core 10 17744 running over Raspberry Pi 3.
I try to initialize COM port from UWP application using following code:
string aqs = SerialDevice.GetDeviceSelector();
DeviceInformationCollection devices = await DeviceInformation.FindAllAsync(aqs);
List<DeviceInformation> list = devices.ToList();
DeviceInformation di = list.First();
_serial_port = await SerialDevice.FromIdAsync(di.Id);
I have di.Id -> \\?\ACPI#BCM2836#0#{86e0d1e0-8089-11d0-9ce4-08003e301f73}
Full represintation of di variable as follow:
- di {Windows.Devices.Enumeration.DeviceInformation} Windows.Devices.Enumeration.DeviceInformation
EnclosureLocation null Windows.Devices.Enumeration.EnclosureLocation
Id "\\\\?\\ACPI#BCM2836#0#{86e0d1e0-8089-11d0-9ce4-08003e301f73}" string
IsDefault false bool
IsEnabled true bool
Kind DeviceInterface Windows.Devices.Enumeration.DeviceInformationKind
Name "MINWINPC" string
- Pairing {Windows.Devices.Enumeration.DeviceInformationPairing} Windows.Devices.Enumeration.DeviceInformationPairing
CanPair false bool
+ Custom {Windows.Devices.Enumeration.DeviceInformationCustomPairing} Windows.Devices.Enumeration.DeviceInformationCustomPairing
IsPaired false bool
ProtectionLevel None Windows.Devices.Enumeration.DevicePairingProtectionLevel
Native View To inspect the native object, enable native code debugging.
+ Properties {System.__ComObject} System.Collections.Generic.IReadOnlyDictionary<string, object> {System.__ComObject}
Native View To inspect the native object, enable native code debugging.
But after await operation I have null in _serial_port.
UPDATE
It is null even if I connect Raspberry UART interface to working node:
8th pin as TX to paired RX line.
10th pin as RX to paired TX line.
UPDATE
I have DeviceCapability in manifest:
<DeviceCapability Name="serialcommunication">
<Device Id="any">
<Function Type="name:serialPort" />
</Device>
</DeviceCapability>
You need add serial device capability in the Package.appxmanifest:
<DeviceCapability Name="serialcommunication">
<Device Id="any">
<Function Type="name:serialPort" />
</Device>
</DeviceCapability>
It is null even if I connect Raspberry UART interface to working node:
8th pin as TX to paired RX line. 10th pin as RX to paired TX line.
This is not required for SerialDevice.FromIdAsync() success. Even if you don't connect these pins the SerialDevice.FromIdAsync() can get the valid device if the code and setting correctly. You can refer to Serial UART Sample.
Related
In an external kernel module, using DMA Engine, when calling dma_request_chan() returns an error pointer of value -19, i.e. ENODEV or "No such device".
Now, in the active device tree, I do find a dma-names entry with what I'm trying to get a channel for, so my suspicion is that something else deeper in the forest is already not found.
How do I find out what's wrong?
Background:
I have a Zynq MP Ultrascale+ board here, with an FPGA design which uses AXI VDMA block to provide one channel of data to be received on the Cortex A's Linux, where the data is written to DDR4 by the FPGA and to be read from Linux.
I found that there is a Xilinx DMA driver included in the kernel, in the Xilinx source repo anyway, currently kernel version 5.6.0.
And that that driver has no user space interface, such that an intermediate kernel driver is needed.
This is depicted, and they have an example here: Section "4 DMA Proxy Design". I modified the code in the dma-proxy.c of the zip file linked there such that it uses only the RX channel, i.e. also only tries to request it.
The code for that is here, to not make this post huge:
Modified dma-proxy.c at onlinegdb.com
Line 407 has the function create_channel(), which used to use dma_request_slave_channel() which ditches the error code of the function it wraps, so to see the error, I am using that one instead: dma_request_chan().
The function create_channel() is called in function dma_proxy_probe() # line 470 (the occurences before that are deactivated by compile switch).
So by way of this call, dma_request_chan() will be called with the parameters:
create_channel(pdev, &channels[RX_CHANNEL], "dma_proxy_rx", DMA_DEV_TO_MEM);
The Device Tree for my board has an added node for dma-proxy driver as is shown at the top of the dma-proxy.c
dma_proxy {
compatible ="xlnx,dma_proxy";
dmas = <&axi_dma_0 0>;
dma-names = "dma_proxy_rx";
};
The name "axi_dma_0" matches with the name in the axi DMA device tree node:
axi_dma_0: dma#a0000000 {
#dma-cells = <0x1>;
clock-names = "s_axi_lite_aclk", "m_axi_s2mm_aclk";
clocks = <0x3 0x47 0x3 0x47>;
compatible = "xlnx,axi-dma-7.1", "xlnx,axi-dma-1.00.a";
interrupt-names = "s2mm_introut";
interrupt-parent = <0x1d>;
interrupts = <0x0 0x2>;
reg = <0x0 0xa0000000 0x0 0x1000>;
xlnx,addrwidth = <0x28>;
xlnx,sg-length-width = <0x1a>;
phandle = <0x1e>;
dma-channel#a0000030 {
compatible = "xlnx,axi-dma-s2mm-channel";
dma-channels = <0x1>;
interrupts = <0x0 0x2>;
xlnx,datawidth = <0x40>;
xlnx,device-id = <0x0>;
};
If I now look here:
% cat /proc/device-tree/dma_proxy/dma-names
dma_proxy_rx
Looks like my dma_proxy_rx, that I'm trying to request the channel for, is in there.
Edit:
In the boot log, I see this:
xilinx-vdma a0000000.dma: Please ensure that IP supports buffer length > 23 bits
irq: no irq domain found for interrupt-controller#a0010000 !
xilinx-vdma a0000000.dma: unable to request IRQ 0
xilinx-vdma a0000000.dma: WARN: Device release is not defined so it is not safe to unbind this driver while in use
xilinx-vdma a0000000.dma: Xilinx AXI DMA Engine Driver Probed!!
There are warnings - but in the end, the Xilinx AXI DMA Engine got "probed", meaning the lowest level driver loaded and is ready, right?
So it looks to me like there should be my device, but the kernel disagrees.
I've got the same problem with similar configuration. After digging a lot of kernel source code (especially drivers/dma/xilinx/xilinx_dma.c) I've solved this problem by changing channel number in dmas parameter from 0 to 1 in dma-proxy device tree entry like this:
dma_proxy {
compatible ="xlnx,dma_proxy";
dmas = <&axi_dma_0 1>;
dma-names = "dma_proxy_rx";
};
It seems that dma-proxy example is written for AXI DMA block with both mm2s (channel #0) and s2mm (channel #1) channels. And if we remove mm2s channel from AXI DMA block, the s2mm channel stays #1.
I want to know if it is possible to connect multiple RC522 to one Raspberry PI, if yes how do we do it? I read in some articles that with CS(chip select) pin we can control Readers, but the CS pin is not present on RC522 I have.
Can you please help me?
Chip Select (CS) is referred to as SS or NSS in some of the RFC522 documentation, is that the issue? If so, connect your CS0 to NSS on one module, CS1 to the NSS on the other, and you can use both modules on the same SPI bus.
If you need more devices than that, you could switch to the I2C interface. In I2C mode, a number of the pins on the chip become address selects, so you can put a whole bunch of them on the same I2C bus. The data sheet for the chip is always helpful with this sort of information. Section 8.1, "Digital interfaces" may be particularly helpful.
In I2C mode, you have 5 bits of addressing, so you can put up to 32 devices on the bus.
Posted this answer before on the raspberry pi stackexchange.
I'll just repost it here for visibility.
You can use the RST Pins to select the reader you want to use. Connect all the other pins in parallel (see schematic below). Just set all the RST pins to low, except the one on the pin you want to use. Set that one to high. Then initialize SPI, read/write, and close SPI again.
I wrote a more detailed explanation here.
This is the schematics and code I made:
Schematic for 2 readers
Schematic for 4 readers
Code to run it all (using pimylifeup's MFRC522-Python Library):
import RPi.GPIO as GPIO
from mfrc522 import SimpleMFRC522
import spidev
class NFC():
def __init__(self, bus=0, device=0, spd=1000000):
self.reader = SimpleMFRC522()
self.close()
self.bus
self.boards = {}
self.bus = bus
self.device = device
self.spd = spd
def reinit(self):
self.reader.READER.spi = spidev.SpiDev()
self.reader.READER.spi.open(self.bus, self.device)
self.reader.READER.spi.max_speed_hz = self.spd
self.reader.READER.MFRC522_Init()
def close(self):
self.reader.READER.spi.close()
def addBoard(self, rid, pin):
self.boards[rid] = pin
def selectBoard(self, rid):
if not rid in self.boards:
print("readerid " + rid + " not found")
return False
for loop_id in self.boards:
GPIO.output(self.boards[loop_id], loop_id == rid)
return True
def read(self, rid):
if not self.selectBoard(rid):
return None
self.reinit()
cid, val = self.reader.read_no_block()
self.close()
return val
def write(self, rid, value):
if not self.selectBoard(rid):
return False
self.reinit()
self.reader.write_no_block(value)
self.close()
return True
if __name__ == "__main__":
nfc = NFC()
nfc.addBoard("reader1",5)
nfc.addBoard("reader2",6)
data = nfc.read("reader1")
nfc.write("reader2",data)
I am using I2C on the Snowball board, running at 400KHz by default and would like to reduce this to 100KHz.
I use the api defined in and configure as follows
m_fd = open(m_filename.c_str(), O_RDWR);
if (ioctl(m_fd, I2C_SLAVE_FORCE, m_addr) < 0)
{
throw I2cError(DeviceConfigFail);
}
Does anyone know how I would go about changing the speed to standard mode.
Thanks
You can change the I2C SCL frequency in your driver's 'struct i2c_gpio_platform_data'.
static struct i2c_gpio_platform_data xyz_i2c_gpio_data = {
.sda_pin = GPIO_XYZ_SDA,
.scl_pin = GPIO_XYZ_SCL,
.udelay = 5, //#udelay: signal toggle delay. SCL frequency is (500 / udelay) kHz
....
};
Changing 'udelay' changes your 'xyz' i2c device's clock frequency.
You should change the I2C Frequency in driver source file of the corresponding peripheral (ie: Slave device to which you are communicating through I2C. Example: EEPROM/Camera etc.)
You may find some macro defined in that driver source code... like:
#define EEPROM_I2C_FREQ 400000 //400KHz
Change it to:
#define EEPROM_I2C_FREQ 100000 //100KHz
Only for that corresponding driver, I2C frequency/speed will be changed.
How can i fetch SIM number or phone serial number in windows phone 7? In Android I use this code and it works:
/ Get the SIM country ISO code
String simCountry = telephonyManager.getSimCountryIso();
// Get the operator code of the active SIM (MCC + MNC)
String simOperatorCode = telephonyManager.getSimOperator();
// Get the name of the SIM operator
String simOperatorName = telephonyManager.getSimOperatorName();
// -- Requires READ_PHONE_STATE uses-permission --
// Get the SIM’s serial number
String simSerial = telephonyManager.getSimSerialNumber();
There is no API available for 3rd party developers to access the phone or SIM number.
I am a bit confused by the USB IOCTL IOCTL_USB_GET_ROOT_HUB_NAME. What is the target device of it? Although the MSDN WDK doc clearly indicates the target device, I am still confused by the USBVIEW sample provided by the WDK. The reason I'm confused is as follows:
I am new to kernel mode and USB driver writing in Windows and is now studying the USBVIEW sample from the windows driver kit http://msdn.microsoft.com/en-us/library/ff558728(v=vs.85).aspx. The MSDN describes the first step the USBVIEW sample performs as:
Enumerate host controllers and root
hubs. Host controllers have symbolic
link names of the form "HCDx", where x
starts at 0.
Use CreateFile() to open each host
controller symbolic link.
Create a node in the tree view to
represent each host controller.
After a host controller has been
opened, send the host controller an
IOCTL_USB_GET_ROOT_HUB_NAME request to
get the symbolic link name of the root
hub that is part of the host
controller
But, I double checked the usage of IOCTL_USB_GET_ROOT_HUB_NAME in MSDN http://msdn.microsoft.com/en-us/library/ff537326(v=VS.85).aspx
which says:
IOCTL_USB_GET_ROOT_HUB_NAME is a
user-mode I/O control request. This
request targets the USB hub FDO.
Note that the target of the IOCTL_USB_GET_ROOT_HUB_NAME IRP is a USB Hub FDO. However, as described by the USBVIEW sample, we just retreived the host controller symbolic link which means the device object is a host controller device object. How could we send it a IOCTL_USB_GET_ROOT_HUB_NAME IRP? Should we retreive a USB hub FDO somehow first?
I would guess it's an unfortunate copy-paste error. IOCTL_USB_GET_ROOT_HUB_NAME is indeed sent to the host controller and therefore handled by the USB Host Controller FDO.
By the way, just to put you in context:
The term "FDO" only loosely concerns user mode -- it's not like you can access any other "xDO" anyway. If you were to send this IOCTL in kernel mode, then sure, you can send an IOCTL to any specific device object in the device stack ("can" doesn't mean "should", mind you). However, a DeviceIoControl from a user mode application always sends IOCTLs to the top of the device stack (therefore it passes all the filters, the FDO and down to the PDO).
This question was asked on March 28, so I really hope you've solved it by now :)
As the documentation states you will need a handle to the USB host controller but it is not very clear on how you are supposed to get such a handle. In USBView something similar to this function is used to get the device path name by passing GUID_DEVINTERFACE_USB_HOST_CONTROLLER (include initguid.h and usbiodef.h):
vector<wstring> EnumDevices(
_In_ const GUID Guid
)
{
vector<wstring> r;
int index = 0;
HDEVINFO hDevInfo = SetupDiGetClassDevs(&Guid, NULL, NULL, DIGCF_PRESENT | DIGCF_DEVICEINTERFACE);
SP_DEVINFO_DATA DevInfoData;
memset(&DevInfoData, 0, sizeof(SP_DEVINFO_DATA));
DevInfoData.cbSize = sizeof(SP_DEVINFO_DATA);
while (SetupDiEnumDeviceInfo(hDevInfo, index, &DevInfoData)) {
index++;
int jndex = 0;
SP_DEVICE_INTERFACE_DATA DevIntData;
memset(&DevIntData, 0, sizeof(SP_DEVICE_INTERFACE_DATA));
DevIntData.cbSize = sizeof(SP_DEVICE_INTERFACE_DATA);
while (SetupDiEnumDeviceInterfaces(
hDevInfo,
&DevInfoData, &Guid, jndex, &DevIntData
)) {
jndex++;
// Get the size required for the structure.
DWORD RequiredSize;
SetupDiGetDeviceInterfaceDetail(
hDevInfo, &DevIntData, NULL, NULL, &RequiredSize, NULL
);
PSP_DEVICE_INTERFACE_DETAIL_DATA pDevIntDetData = (PSP_DEVICE_INTERFACE_DETAIL_DATA)malloc(
sizeof(SP_DEVICE_INTERFACE_DETAIL_DATA) + RequiredSize
);
memset(pDevIntDetData, 0, sizeof(SP_DEVICE_INTERFACE_DETAIL_DATA) + RequiredSize);
pDevIntDetData->cbSize = sizeof(SP_DEVICE_INTERFACE_DETAIL_DATA);
SetupDiGetDeviceInterfaceDetail(
hDevInfo,
&DevIntData,
pDevIntDetData, RequiredSize,
NULL,
&DevInfoData
);
r.push_back(wstring(pDevIntDetData->DevicePath));
free(pDevIntDetData);
}
}
return r;
}
Keep in mind using the above function you can also request devices of type GUID_DEVINTERFACE_USB_HUB and GUID_DEVINTERFACE_USB_DEVICE which may eliminate any need to interact with the host controller or hubs directly.