I run a program using two USB devices, a USB-RS422-WE (USB <-> UART) and a UMFT4222EV-D (USB <-> i2c), with the FTD2XX library.
The first thing the program does is looking for these two devices using FT_ListDevices (for each, a specific device is looked for, by serial number for the USB-RS422-WE, by location for the UMFT4222EV-D). For each device, if it is found to be connected, it is then opened with FT_OpenEx.
When the USB-RS422-WE is the only device connected, it is properly detected and subsequently opened with no error.
However, when both devices are connected, the USB-RS422-WE is still properly detected but the opening fails with error 2 DEVICE NOT FOUND.
I've come to a minimal exemple, where the issue is completely reproducible, independently of previous executions of the program, and with different "copies" of the devices.
Do you have any idea how to investigate this issue?
Related
I have a program written in Visual Basic (.NET Framework 3.0) that communicates with a power supply via a D2XX driver (over COM3) and a pump via a VCP driver (over COM2). Currently, if both USB devices are plugged in when I start the program, it tries to communicate with the pump, (COM2) when trying to communicate with the power supply (COM3). I found a temporary solution to this issue by only have the power supply connected when starting the program. Then I initialize communication with the power supply, and afterwards plug in the pump; this allows the program to communicate with both separately for the rest of the time running the program. But this process is tedious and I am hoping there is an alternative solution where I can keep both units connected via USB and the computer communicates separately. What is confusing is that this communication issue was not always the case, a week ago it worked without having to disconnect the pump (all drivers are updated, and on the device manager they are listed as their respective COM ports as well) ; I am struggling to find some correlation between what is the underlying issue.
I tried to delete other hidden additional COM ports. I made sure all drivers were updated. When the pump is communicating via the same port as the power supply, and then I try to communicate with the pump, I receive this error:
System.UnauthorizedAccessException
HResult=0x80070005
Message=Access to the port 'COM2' is denied.
Source=<Cannot evaluate the exception source>
StackTrace:
<Cannot evaluate the exception stack trace>
But again, If I start the program with only the power supply plugged in and initialize communication with the power supply, and THEN plug in the pump, this issue is evaded. I hope someone can give some sort of direction at all troubleshooting this issue because I am completely stumped. Thank you!
Most likely your program implicitly relied on the correct enumeration order. If you use devices with an FTDI product with internal flash or with dedicated eeprom, you may be lucky: Many can configured via FT_PROG to be visible only for D2XX and not as VCP. This way you can avoid the problem. Alternatively, you can try to modify your program so that it accesses D2XX first. Make sure to filter out the correct device using device informations. E.g. the serial number or the VID:PID if the device manufacturer has made the effort to aquire its own IDs. Check 3.4 FT_GetDeviceInfoList of D2XX Programmer's Guide for details.
I'm facing issues when communicating with devices over USB hub. When enumerating devices directly to host port, it does work, some devices over usb hub have issues.
Setup: STM32F103C8 - MAX3421E - LUFA (usb stack) (ported to MAX3421E (host) and STM32F103C8T6 (device)) - USB Full-Speed setup
Scenario:
When I attach device directly to host, I don't experience any issues enumerating almost all (some devices seems to be faulty and have weird/nonstandard behavior) devices. But when I try to enumerate over usb hub, devices starts to behave very strangely. I'm receiving much more NAK's from devices than when connected directly to host. Some devices are able to return Device Descriptor, but retrieving Configuration Descriptor fail. Some devices return Toggle Error after several NAK's, this could be remedied so far by delaying retry IN token. Also there is different behavior of devices when connected over different hubs. I.e. one device has no problems when connected to HUB1, but have issues when connected to HUB2. Then I have HUB3 (7 port) which internally acts as HUB in HUB. On this HUB3 device working fine on port behind secondary internal hub, but not on primary ports exposed over "root" hub.
I'm in suspicion that hub's TT could be somehow interfering with usb communication, but according to information I have found, TT should not be enabled under Full-Speed setup.
I have checked (many times) that I'm setting correct device address assigned during SetAddress phase (which is proved by returning Device Descriptor). When I step debug it seems that I can get Configuration Descriptor also, but while in normal system run, it isn't retrieved, but only over hub.
Does anyone has any ideas, what to look after? I've run out of ideas here after week of trying to find a root cause.
Thanks
so...
- as usual after searching for root cause, solution after days of trying comes naturally after asking on somewhere (this is hapenning to me always, but I do try prior asking always)
- when using hubs, make sure you don't suspend SOF generation during control transfers. LUFA just resume bus inside control transfer routines, so make sure you don"t stops and reenable SOF within (my fault as I'm using ported version to MAX)
- if you have tight main loop make sure you don"t reinitialize usb transfer without completion of previous try, but if you do so, check you don't owerwrite data which haven"t been processed yet fully (especially when using interrupt-driven transfer complete processing) [things seems to work when you have quite some debug output, as it delay that time critical transfers]
Enumeration over hub isuues are now second to none. Small glitches are subject for tweaking.
Unfortunately as I was in question for electrical issues, I had to unsolder usb host shield and soldered another one, which in light of new information seems unneeded. Nevermind, I have trained my soldering skills.
I'm at the beginning of trying to develop a USB HID bootloader for a Kinetis processor, and getting no help from that department. I have made some modifications to Kinetis firmware designed for a similar processor(I'm using the KL26Z, the original code is for KL25Z), and I do now see the beginning of the USB enumeration(on a PC running W7). However, the PC asks for driver software, and I don't understand why, as I thought the whole point of going the HID route was that one didn't need to install drivers. So the device shows up under device manager, but as a non-working problem device. My problem is that I don't really know what should happen. Any insights would be welcome.
Here's what should happen: the computer will ask your device for its USB descriptors when it detects your device. The descriptors must have certain fields like bDeviceClass set properly to indicate that it is an HID. If the computer sees those fields, it will attach the HID driver to your device.
In the Device Manager, you should look at the "Compatible Ids" of your device. Do you see USB\Class_03 in that list? If so, that should match the driver input.inf that comes with Windows, so the INF file will be applied to your device, and you device will show up as "USB Input Device" in the Device Manager. If you don't see USB\Class_03 in your list then there is probably some problem with your device's USB descriptors or its USB stack.
I am trying to access an USB HID device under Ubuntu(kernel-3.0). I want to write a program which could notify me whenever an USB device is attached to the bus i.e is there any event generated whenever an USB device is plugged in which I can monitor. I have looked into DBus and HAL without any success. But I don't want linux to load its current modules(USBHID and HID) when the device is plugged in. I also want to ask if the mentioned modules are also the device drivers used for HID devices.
My sole purpose is to run a script whenever an USB device is plugged into the bus which will indirectly call the above mentioned modules.
I am writing my code in C. I am quite new to linux. So it would be of great help if anyone could point me in the right direction.
Thanks..
The UDisks deamon will send the D-Bus signal "DeviceAdded" when a USB drive is inserted, and probably another "DeviceAdded" for each partition on the drive. If you have automount you would also get a "DeviceChanged" signal when the partition(s) are mounted. You can then query the UDisks interface, as well as individual devices about their properties, for example. You can find more info on the UDisks interface here: http://hal.freedesktop.org/docs/udisks/UDisks.html
One way to get more familiar with what goes on with block devices (or whatever) on D-Bus, is to install and use D-Feet to inspect the bus. UDisks appear on the System bus. You can see what is there and inspect the properties for individual devices as well as the UDisks interface itself.
Another way, which would also allow you to see what signals are transmitted on the bus, is to run dbus-monitor from the command line.
I am writing an Usb driver and I have an issue.
When I insmod the driver with the device already plugged in before hand, the probe function is not called. It is only called after I disconnect the device and plug it again.
I want to make it so that it works when I start my pc with the device already plugged in.
Could someone please help me?
From Documentation/driver-model/binding.txt:
When a new device is added, the bus's list of drivers is iterated over
to find one that supports it. In order to determine that, the device
ID of the device must match one of the device IDs that the driver
supports. The format and semantics for comparing IDs is bus-specific.
From the same source:
The process is almost identical for when a new driver is added.
The bus's list of devices is iterated over to find a match. Devices
that already have a driver are skipped. All the devices are iterated
over, to bind as many devices as possible to the driver.
So it looks like you have a problem in the ID matching, that is in your case specific to the USB bus, see the usb_device_match function in drivers/usb/core/driver.c.
Or it may be that your device already is bound to a device that is unloaded when the device is unplugged (you can check that by controlling if there is a symlink to a driver in the corresponding /sys/bus/usb/xxxxx directory)
"Or it may be that your device already is bound to a device that is unloaded when the device is unplugged (you can check that by controlling if there is a symlink to a driver in the corresponding /sys/bus/usb/xxxxx directory)"
And if there is a symlink?
This can be solved by writing a proper udev rule for your device. Look for examples at /etc/udev/rules.d/