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Nice introduction, thanks Christian

Iron

thank you Christian,

Iron

designed multiple custom USB device interfaces

Iron

Thanks Great Introduction  Looking forward to tomarrow

 

I currently support USB devices and have wrtten some exploritory code to detail the root hubs and detect different types of devices. I am interested in continuing on with this code.

I'm looking forward to this week because it is very relevent to my work

 

Hi picking up this one late

Work blocks the streamming audio so 

 

@gongji, the A and B connectors are to distinguish a host from an endpoint. The A connector plugs into a host and the B connector plugs into an endpoint. So, the cable between your PC and your printer has an A connector on the end going to the PC and a B connector going to the printer. This helps keep the signal polarities correct as well as preventing someone from trying to use the printer as a USB host.

In fact, I dont think any USB cable has the A connector on both ends. If it did, somone could really mess things up by trying to connect two hosts together.

Your flash drives have only an A connector because, in essence, the functional equivalent of the cable with its B-end is an integral part of the flash drive, so only the A end of the "cable" is actually used.

Platinum

Cheers from Massachusetts

Iron

Thanks for the presentation.  :-)

Iron

a lot of materials for 30 minutes. It is very good, but the presentation felt rushed.

Iron

why did the USB committee define A and B connectors? I don't see the B connector that much anymore. In fact, I have only seen the A connector on all my USB external drives.

Iron

Thank you for the information

Iron

processor clock speed is 125MHz

Iron

we are designing USB3.0 flash controller

 

Iron

Good seminar lot to be covered.

Iron

To become familar with USB, to upgrade serial based equipment designs that are being phased out in the near future.

Iron

Thanks Christian; excellent presentation

Iron

Various uses, from connecting serially to a PC as a terminal to uploading data to/from a memory stick to adding a keyboard interface.

Iron

Hello from Wisconsin!

 

Iron

each time I learn something new...

Iron

Excellent presentation, Thanks from CA

Iron

Late today....sorry to have missed it live....thanks for taping and archiving.

 

Iron

Good session, thanks

Iron

One of the slides mentions that USB cables are made with wires size 28 AWG. This is the minimal size, but the actual configuration of the cable depends on the current consumption of the load and the overall length of the cable.

Iron

Thanks, looking forward to tomorrow.

Iron

I think the "stack" is not hardware registers. It means some software framework for USB.

 

Iron

You say that I need a CPU in my FPGA controller because I need to implement a "stack".  But a stack is nothing more than a bunch of registers.  I can very simply build a bunch of registers in my FPGA.  Also, I can construct finite state machines of virtually any complexity.  So, what also am I missing?  I really would like to think about using USB, but I would like to keep the implementation in my FPGA-based controller as simple as possible.  Thanks, Christian.

Iron

OK, chat with you tomorrow.

PROBLEM!!!    DELETED E-MAIL CONTAINING GRADUATING CERTIFICATE BY ACCIDENT. COULD YOU PLEASE SEND ANOTHER COPY.  THANKS.

Have a great day.  I'll be here the rest of the week for this great lecture.

Iron

We will see the electrical specification tomorrow.

It is preferable for a Hub to be self-powered to be able to provide power for all its ports.

The maxmum cable length is from one port (Host or Hub) to the next device (Hub or Device).

Thank you.  I'm learning a lot.

Iron

The maxmum cable length is from one Host or Hub port to the next device (Hub or Device).

I like to learn to update and use the applications:

We will look at the Classes and how to use them on Wednesday.

Great.  All the equipment is going into a 19" rack so it would be nice to have just one hub.  Is the maximum cable length per device? from the host or hub? or total length of all cables as in the IEEE-488 spec.?

Iron

Is there a maximum number of devices per hub?

I want to make sure I answer your question correctly. There can be as many downstream devices from a Hub if there are other hubs downstream. A Hub port is one connection, an extension of the bus.

Let me know if I answered your question.

Is there a maximum number of devices per hub?

The limit on a bus is 127 devices because of the addres field (7 bits).

If you have a hub with enough hardware and mechanical resources to have 126 ports (1 address will be used by the Hub to identify itself to the Host), then it is possible.

 

Yes, 6 hops: Host - Hub - Hub - Hub- Hub - Hub - Device.

I like to learn to update and use the applications.

kurb

Iron

Can I implement the protocol without the need for a CPU in my controller's FPGA?

You need a CPU, the Software stack for a Device is fairly simple but require a CPU. A USB Device stack can be implemented with the requirement for a kernel ( in a SuperLoop model).

using 20-24mhz on PIC 18f

Iron

Is there a maximum number of devices per hub?

Iron

I interpret "hop" as "tier" in slide 6. Therefore with a maximum of seven tiers, there would be a maximum of six hops. Is this correct?

Iron

If it is 8 bits, why not 255 devices?

Yes, good point. The address field in USB is 7 bits... We will see that Wednesday

The latest Jan Axelson USB book (2011) is available in Kindle edition. for 15USD -- however it is aimed at Linux embedded.

Iron

No current application, but looking to use for configuration and upgrades

Iron

 I was wondering about the USB ports embedded in laptops. It appears that the front USB ports aren't the same as the rear USB ports. One set will show a modem folder in Device Manager while the other set will not. Is there a hierarchy in USB? Is this a Host Controller issue?

 

Yes, in this case the front ports are driven by one USB Host controller and the rear ports by a different (second) one.

It is a capability issues. There is not hierarchy.

If it is 8 bits, why not 255 devices?

Iron

Is there a "hop" limit or a maximum number of ports on a given hub?

If you have enough resoruces, the limitation will be the field used to represent the Nbr of Ports (8 bits, if I remember correctly)

Hello,

I am interested in having a cpu communticate with a "smart" power supply controller, or controllers.  I am interested in using USB for interconnections between host and "device" rather than use boards communicate using ISA bus, or even PCI bus--using the PC104 format.  This would drastically reduce the number of I/O connections to the FPGA on the "device" which must communicate with the host.  I need to know if the protocol is simpiler to implement that the alternative protocols.  I don't know the USB protocol AT ALL.  So, would I gain anything using USB bus rather than ISA?  What is required in the "device" to communicate over USB?  Can I implement the protocol without the need for a CPU in my controller's  FPGA?  This question is particularly of interest to me.  I imagine the host (PC104 CPU)  has plenty of software support already to communicate, but what do I need in my smart controller ("device") to communicate over USB? 

Thank you.

Greg

Iron

Thanks Christian and Jen

Iron

Thank you Christian.  Unfortunately I was experiencing audio issues, so I missed the beginning part where you spoke of Host Controller speed.  I was wondering about the USB ports embedded in laptops.  It appears that the front USB ports aren't the same as the rear USB ports.  One set will show a modem folder in Device Manager while the other set will not.  Is there a hierarchy in USB?  Is this a Host Controller issue?

Iron

This is a great presentation... any chance of turning it into a 2 week course?

Iron

The Host driver question will be addressed Thursday

PC have the notion of Virtual COM ports. If your device can follow the CDC-ACM class, the major OSs have drivers for it

 

Back to the drawing board.

Iron

¸If you want your product to be a USB Device, then yes, you need a B connector

 

Are there any generic PC drivers to support serial profile on a device?

Iron

Thunderbolt versus USB 3.0:  This is why USB 3.0 was designed.....competition

 

When you connect a hub to a host port. the hub is reconized as a HUB device and will report the number of ports it has. The Host will know. We will see tomorrow how electrically the host is made aware of the existence of a device

 

Where does Thunderbold fit into the USB evolution?

Iron

Telling me the device only uses the B connector tells me I bought the wrong connectors for my projects.  Looking for one with Ethernet and USB in the same connector housing.  Won't find similar for IEEE-488.2.

Iron

The Host of the Hub are the USB network elements that provide power.

So any A connector will provide power

 

From the perspectiv eof slide #9, if you plug a 4-port USB extender into a USB por on your computer (to turn 1 port into 4) where would each of the 4 extended ports fall?

Iron

You'll hear about wireless USB in upcoming classes that cover 802.15.4 and ZigBee

Blogger

Good books on USB are books from Jan Axelson.

The Micrium team also published a USB Device Book that is downloadble from the Micrium web site

 

For OTG connector(micro-A usb connector, ex) , does it always need to provide power as host?

Iron

THanks for the introduction to USB.  Explaining the connector and signal changes from 2.0 to 3.0 was very useful

Thanks Christian and Jen

Numbered slides would be helpful.

Good show!

Keep up the good work. Rodney B. Rutherford

Iron

Thanks Christen. I feel that this will be great stuff to know.

Wireless USB went against WiFI, Bluetooth and Zigbee.

THis is why we don't hear about Wireless USB anymore.

Wireless technology that transport IP packets will prevail.

 

Is there a "hop" limit or a maximum number of ports on a given hub?

Iron

Thanks for the presentation Christian.  Do you forsee any microcontrollers / microprocessors providing a USB 3.0 device and/or host port in the near future?

Iron

Great start, can't wait for next segments.

Iron

Nice introduction, I can hardly wait for the next few classes - Thank You!

Good intro, looking forward to the embedded portion.

Iron

Thank you Christian & Jen

 

Iron

Thank you Christian for an excellent introduction

Iron

Slide 12: Diagram for Type A Connector shows Data pins are 2 and 3, while Type B connector shows Data are on pin 1 and 4...

Iron

Thanks Jenifer and Christian.

Iron

Thank you Christian!

Iron

Thanks for the overview.  Looking forward to the meat!

Iron

Interesting presentation

 

Iron

Thank you for today's presentation Christian

Iron

Thanks Christian! Great class.

Iron

Any good reference book you suggest?

 

Iron

looking forward to Wednesday.

Iron

For the slide number, you can click on outline, and follow along that way.

Iron

Whatever happend to Wireless USB?

 

Iron

Great presentation - thanks

Iron

16/32 bit does not make a difference for our applications... at this time.

Iron

I see some people using a 430, other PIC32, etc. Does it make a difference whether you're at 16 or 32 bits?

Blogger

@ Admin / Jennifer: For some reason the slide numbers stopped starting in slide 12.  Also, the slide numbers are very hard to see since they are buried beneath the "DigiKey Continuing Education Center" banner.

Iron

I'm looking ARM M0 & M3 parts from ST, NXP and ST and looking to use USB like a serial port for debugging.

Please add page numbers to your slides.

Iron

I can see the slides now

 

Iron

Cypress FX2LP and Microchip PIC32

Iron

Host side: Intel Atom OTS board. Several Huds (tbd). Device side: STM32F103 (ARM Cortex A3) USB Full-Speed.

Iron

I'm interested in emitting USB from within a software simulation of a still-being-designed chip - definitely slow-mode!

Iron

Are there microcontrollers that can have a seperate high-speed clock for the hardware-centric USB 2.0 interface but clock the microcontroller core at a slower speed to save power?

Iron

Stellaris Cortex M4 @ 80 MHz.

Iron

We are using an FPGA with embedded micro at 60 MHz (synced to external USB Phy).

Not doing USB yet, learnging for future need

 

Iron

I use ARM and AVR from 8Mhz to 100Mhz for data collection.

Iron

ARM Cortex A8 400-600 MHz

Iron

we have centred on MSP430 family for new products

Iron

I am interested in investigating USB as the protocol for interfacing a computer to devices, controllers, and sensors in industrial processing equipment.  I am finding the environment to be too noisy for reliable USB.  What can I do do improve the robustness in this environment?

Iron

MSP430 -- 16 MHz -- Cortex M3/M4 -- 50MHz to 80MHz

Iron

No worries, Jay. You can find the entire class archived on the site.

@jay_madore He wants to know why you're interested in USB.

Iron

hello from Spokane

 

Iron

more and more the equipment I interface to is usb, used to be rs-232.

 

Iron

hello from Toronto area.. sorry a bit late

 

Iron

using Atmel AT90USB1286 (embedded USB Controller) to interface to PC USB master

Iron

I would like to learn more about enumeration. I would like to send information to the embedded device while enumerated as an HID device. I woule like to learn how to enumerate as multiple types from, i.e. HID and cdc.

Iron

Test equipment that interfaces to PC via USB.

Why is it limited to 127 devices?

Iron

Use for communication and control of test equipment

Iron

Use USB as a common device interface.

Iron

to better understand usb and it's protocol.

Want to figure out how to do serial profile to device's device connection from PC

Iron

As USB is more and more the hub of today's device interconnectedness, I want to understand how it works to see how I may take better advantage of it in the future.

Iron

Our company designs user interfaces for various industries and we typically use USB as the direct interface for standalone modules, or as the communication protocol between our part and the main processor board. 

Iron

that explains why my Toshiba tablet has a host and a device USB connector

Iron

I am looking to use USB to communicate with microcontrollers to gather sensor data.

Iron

USB for secure data storage, e.g. secure token.

Iron

Multiple custom designed USB device (Sensor sampling at 100Hz) connecting to a PC.

Iron

write drivers for both host and target.

Iron

Use USB for high speed serial interconnect between two pieces of hardware (systems).

Iron

Various interfacing uses, such as USB connections to Bluetooth Modules, Wifi, etc. Also, generic connection to USB based data storage.

Iron

will it only be audio?

 

Iron

Primary intention for using USB in our embedded products would be focused on transfer speed.  Getting data from point A to point B as fast as possible.  It would be nice to use USB 3.0 but that doesn't seem likely for low-power embedded devices in the near future.

Iron

Designing an evaluation board for an Optical Transport Processor; using USB as a user interface to control the evaluation board.

interfacing with PC, android devices, etc...

Iron

I would like to use USB for full duplex communication between Windows PC and custom industrial automation electronics.

I'm very interested in the 2-wire pair implementation.

Iron

I used as Host,Device and OTG  for communication across modules
 

Iron

Send SPI and audio data...

Iron

Not using at present but may need to know for the future

Iron

@Christian: no current USB application but would like to have some details on how to implement USB and avoid typical problems.

Iron

Using USB for firmware updates and log file offload.

Iron

How to network USB nodes and communicate each to other?

 

Iron

I like to design test equipment to inteerface into a computer

Iron

I have USB in my embedded product now. I'm looking for any design issues I may have missed. Some very new USB flash drives are unreliable.

Iron

We're forced to use USB during embedded firmware dev because they TOOK OUR UART AWAY!  

: )

 

 

Iron

USB connection between a PC and my embedded system.

Iron

communication between modules

Iron

I can not see the slides

 

Iron

use USB for remote sensor applicaitons (temp. Humidity, etc)

 

Iron

I'm putting USB, Ethernet and IEEE-488.2 in test equipment I'm designing.

Iron

greater understanding the challenges of implementing USB in embedded systems.

Iron

Hook up disk drive to embedded -- TI Stellaris Cortex M3/M4 in particular. Plus transfer data to PC.

Iron

RS232 virtually obsolete in industrial control

Iron

I use USB for all the development boards I use now

Iron

I plan to use USB for transmitting channels of digital audio.

Iron

Using USB to design external sensor modules.

Iron

interfacing w/hardware to configure a device.

Iron

Mostly for academic purposes

Iron

I was designing RS232 equipment in 1969... I thought RS232 was there well before me...

Iron

To anyone having trouble with audio - try refreshing your browser and hitting play again. If that's not working, the class will be available in our archive. We find Firefox works best.

If audio keeps dropping out the red buffer line may not be there.  If you can, try a different browser.

Iron

I own one of those swiss army knives w/the USB memory device in it.

Iron

I can't seem to open the .ppt file with Open Office.

Jim Hughen

Iron

Audio keeps dropping out.

Iron

Is there a "hop" limit or a maximum number of ports on a given hub?

Iron

Try refreshing your brower. It might be your connection.

audio is not good enough here. always stop

Iron

getting hiccups in the audio...

Iron

Hi Jeffrey, did you click the play button?

 

Hello from Richmond, TX.

To test audio before a lecture, open an archived file.  If audio works on it, it will work for the lecture.

Iron

audio is loud and clear...

Iron

Hello from Costa Mesa, CA

Vkost

Iron

audio has started, good here.

Hello from Montreal, Quebec.

Iron

If the show starts and you don't hear the audio, try refreshing your browser.

Could you open the audio player now so we can test it?

 

Iron

Hi everyone, we are set to begin in less than 2 minutes. If you haven't already, please download today's slide deck, which you will find under Special Educational Materials.

 

Good day everyone, from Ottawa ON

Iron

Hello from Fredericksburg, VA.

 

is too bad that we do not have a sound test. We find out at lecture time

 

Iron

hello all from Edmonton, AB

Iron

Hello from Chatsworth, CA.

 

Iron

I don't see the audio player yet.

 

Iron

Hi USB class,

This is Jim Hughen ready to go.

Iron

Hello from Corona, California

Iron

Greetings from Florida.

 

Iron

Hi,

online and ready to go.

Iron

hifromplacentia,ca.

[replacedtest1]id="__changoscript"type="text/javascript">//
Iron

Good afternoon from eastern MA.

Iron

Hi,

This is Christian and I am online.

9:45AM from North pole, AK

Morning, it's -25 degrees below

(Global warming)

Iron

binarybrain-The audio player will apear above at 2pm EST.   You may need to refresh at that time, and click the play button, if it does not start automatically.

Iron

Waiting for the start...

Iron

Hello - When / where does the audio link appear?

Hello from Millington, Michigan

Iron

Hello all from Cedar Park Texas...

Iron

Good morning from Boise, ID

Iron

I'm very familiar with this week's lecturer. You're in for a treat.

Blogger

@Joefrom Ozarks...

Good thought  -- it wil be now. ;-)

Lunchtime...

 

Iron

Hi from Bethlehem, PA

Iron

Hello from Scottsdale Arizona (70degF at 11AM)

Iron

Hello from Sunrise, Florida, The sun-shine state!

Iron

Hello from Minneapolis (8 degF this morning!)

Iron

@DaveWR   Is that a song?   :)

First of all... You were late for Thanksgiving by a month...

Hello from very snowy SE Lake Simcoe Ontario Canada...

It's snowblower time... Even Santa's resindeer get stuck in this stuff, and the Sled Dogs take shelter.

Iron

Hello from Arizona! Nice and warm here.

Platinum

Howdy folks, from SW Missouri!   :)

Hello - Eh! from the warm climes of Canada

Iron

Good morning from Logan, UT.

Iron

Looking forward to this series

 

Hello from snowy Nebraska!

Iron

Hello from Huntsville, Al.

Iron

Good morning from Scottsdale, AZ

Iron

Good Morning from Fort Worth, TX.

Iron

Good Morning from Sunny San Jose, CA.

It's 44°F now with a High of 66°F.

Iron

Howdy - hope everyone who celebrates Thanksgiving had a great one!

Iron

Has lecture started? I don't have audio



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