I'm wondering if Firefox OS handsets could be useful as a platform for DIY hardware projects. Hence my question: Can Firefox OS apps read out USB pins?
Compared with Arduino it would be obviously be overpowered, but the handsets have decent battery life and all connection stuff like wifi already built in.
Not right now, but we are working on USB support as part of the WebAPI work. The bug to monitor is here: https://bugzilla.mozilla.org/show_bug.cgi?id=737153
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I would like to use a windows machine as a USB488/USBTMC device. USB488/USBTMC is a reimplementation of the good old GPIB/IEEE-488 on USB rails. But most articles on the topic refer to a Windows machine as a host/controller. The Windows USB stack is not well suited for USB device/USB OTG modes. However, if you look at some of the high-end gear like oscilloscopes and spectrum/network analyzers, it is well known that they are often Windows machines inside with some additional hardware. So, how it is done?
To some background: it is a project to retrofit a very old SEM microscope with new hardware. The current one is a 68k custom system with a CRT that uses a GPIB interface for comm with a PC. Things like sample spectroscopy are done as a BASIC program running on a pc and communicating through that gpib port. The plan is to replace that 68k junk with a modern day windows pc with an FPGA on a PCIe bus. For compatibility reasons, it would be nice to have a usb488 port in the new PC. Though I have no idea of how to do it properly. The only solution I have so far is to have some cheap USB-capable micro hanging on the SPI bus on the FPGA facing side and a USBTDM class on the USB side. But maybe Im missing something and there is a specific thing or chip that exists that can do it that Im not aware of.
I can only speculate how high-end oscilloscopes achieve it. The most likely option is that they use a dedicated chip like a MAX3420E. It is connected via SPI. Part of the USB protocol is implemented by the chip, part of it will be implemented by the oscilloscope software.
Most USB controllers chips found in PCs can operate as the host only. And even if they could do a role swap, Windows (for Desktop) has not supported device/peripheral mode until recently. It now does. See USB Dual Role Driver Stack Architecture. But I don't fully understand it to tell you what hardware you would need to purchase where this feature is enabled.
Role swapping is very common on smartphones. It is also implemented in Linux (search for "Linux USB gadget"). Many Apple Macs can run in Target Disk Mode, which is a USB device/peripheral mode as well.
For testing purposes I need to power off a USB device from my computer programmatically. The microprocessor in the USB device is ARM Cortex M4.
I have tried using Devcon, although the device was disabled, power was still provided to the device.
I have also tried to disable the USB root hubs ,that also didn't work.
I have read some other posts indicating that a SSR could be used, this option is not desired. I would rather choose the software solution(if there is one of course).
Some other answers have indicated that this is an OS issue, and some others a chip-set architecture issue.
So my question is what options are there available. And also is this purely something dependent on the computer side or do we need to implement something on the USB device side as well.
Thank you in advance.
Has anybody found the specifications for the USB protocol used by the Xbox controllers? All I can find is the API documentation of Microsoft's implementation (Xinput). I'm trying to write a driver for OS X so Xinput controllers will appear as normal HID devices. Without the specs I'm pretty at a loss...
There is a linux driver here https://github.com/Grumbel/xboxdrv for the XBox that should get you a long way to getting it working on Mac. I don't think the spec is available legally without signing an NDA and paying Microsoft money.
I have never done any USB development, I'm experienced with programming PIC, AVR micro-controllers and C programming on windows (not windows programming). I want to learn how to develop embedded devices and device drivers that can communicate with PC, Not via serial port emulator in USB hardware.
I like to have some points and resources on who should I approach it.
What software and hardware should I have to start leaning that?
Read this fantastic book: USB Complete by Jan Axelson. Also in his site are comprehensive informations too.
I'm trying to connect a usb sensor (see Toradex) to an android phone (Desire Z) running android 4.0.3.
To test this, I wrote a small app to enumerate the attached device(s).
This supposed to have USB HOST mode implemented and to power the usb sensor (HID)... but it doesn't.
I got a USB OTG cable and now, when I attach the cable, a small icon appears in the status bar (car mode).
I'm disappointed since I waited for this feature for awhile now...
Any thoughts? I read almost everything out there related to this (Sven work and whatnot) but I might have missed something...
Thanks!
I have worked a lot in the past year and a half to build custom android platform. Some was under Froyo but mostly on Gingerbread. Most on the hardware I added was on either a UART or on USB, which is what you want to do. Unfortunately, it is not as easy to add a USB peripheral on an Android device than on a PC or a MAC. PCs and MACs have virtually unlimited memory space (hard drive). They can hold the drivers of a very large number of devices. That makes it possible to do auto-detection and automatic loading of drivers. On an Android device, it is a lot more lean therefor, just the required drivers are stored on the device. Every time I added a new device, I had to compile the driver for my platform and make some modification in my configuration. It is also possible to load the driver as a module instead of compiling it with the kernel (gives a file.ko output). Although, the driver must have been written accordingly. But, you will have to install it by modifying the "init.rc" which requires root privilege.
here is a few link of question/answer about about drivers in Android. That should give you a little bit more info:
USB touchscreen driver
Hope it helps but unfortunately, it is quiet a lot of work do do.