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Guest
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 Posted: Mon Jun 23, 2003 9:11 pm Post subject: New Project Needs a uC |
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Bert
Guest
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| Posted: Thu Jul 17, 2008 7:30 am Post subject: Re: Ethernet design |
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On 16 jul, 22:44, Nobody Here <no...@invalid.invalid> wrote:
| Quote: | I need to start thinking about some Ethernet designs, one as a standalone
switch and the other to integrate a 2 port switch with a microcontroller.
I've looked at some datasheets and reference designs and it doesn't seem
too difficult but I'm losing myself in a seething morass of unfamiliar
acronyms, MII, PHY, OAM Frame, ToS, QoS, VLAN. Well, OK, I've figured out
what most of them mean now but there's still bit to go.
Is there any reference or primer anyone can point me to that will give me
a quick introduction to Ethernet, switches, and interfacing and the like?
I'm an experienced embedded system designer who's never had to deal with
Ethernet before, if that helps judge the level of information I'd like.
A book or a web reference would be OK.
Cheers,
Nobby
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Hi,
I have a huge amount of information (PDF) about Ethernet, I will send
you some by email.
Bye,
Bert |
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Bert
Guest
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| Posted: Thu Jul 17, 2008 7:30 am Post subject: Re: Ethernet design |
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On 16 jul, 22:44, Nobody Here <no...@invalid.invalid> wrote:
| Quote: | I need to start thinking about some Ethernet designs, one as a standalone
switch and the other to integrate a 2 port switch with a microcontroller.
I've looked at some datasheets and reference designs and it doesn't seem
too difficult but I'm losing myself in a seething morass of unfamiliar
acronyms, MII, PHY, OAM Frame, ToS, QoS, VLAN. Well, OK, I've figured out
what most of them mean now but there's still bit to go.
Is there any reference or primer anyone can point me to that will give me
a quick introduction to Ethernet, switches, and interfacing and the like?
I'm an experienced embedded system designer who's never had to deal with
Ethernet before, if that helps judge the level of information I'd like.
A book or a web reference would be OK.
Cheers,
Nobby
|
Hi,
I have a huge amount of information (PDF) about Ethernet, I will send
you some by email.
Bye,
Bert |
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xxx
Guest
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| Posted: Thu Jul 17, 2008 10:25 am Post subject: Re: The Right PCB House |
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Michael A. Terrell wrote:
| Quote: | Roger_the_Codger wrote:
I would have just bought my own software.
There is plenty of free stuff and paid for packages.
There is often something on ebay for a few pounds.
A few pounds of what?
|
Sterling grade refined purified silver, M8. |
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xxx
Guest
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| Posted: Thu Jul 17, 2008 10:25 am Post subject: Re: The Right PCB House |
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Michael A. Terrell wrote:
| Quote: | Roger_the_Codger wrote:
I would have just bought my own software.
There is plenty of free stuff and paid for packages.
There is often something on ebay for a few pounds.
A few pounds of what?
|
Sterling grade refined purified silver, M8. |
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Michael A. Terrell
Guest
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| Posted: Thu Jul 17, 2008 11:28 am Post subject: Re: The Right PCB House |
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xxx wrote:
| Quote: |
Michael A. Terrell wrote:
Roger_the_Codger wrote:
I would have just bought my own software.
There is plenty of free stuff and paid for packages.
There is often something on ebay for a few pounds.
A few pounds of what?
Sterling grade refined purified silver, M8.
|
Isn't that kind of hard to mail?
--
http://improve-usenet.org/index.html
If you have broadband, your ISP may have a NNTP news server included in
your account: http://www.usenettools.net/ISP.htm
Sporadic E is the Earth's aluminum foil beanie for the 'global warming'
sheep. |
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Michael A. Terrell
Guest
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| Posted: Thu Jul 17, 2008 11:28 am Post subject: Re: The Right PCB House |
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xxx wrote:
| Quote: |
Michael A. Terrell wrote:
Roger_the_Codger wrote:
I would have just bought my own software.
There is plenty of free stuff and paid for packages.
There is often something on ebay for a few pounds.
A few pounds of what?
Sterling grade refined purified silver, M8.
|
Isn't that kind of hard to mail?
--
http://improve-usenet.org/index.html
If you have broadband, your ISP may have a NNTP news server included in
your account: http://www.usenettools.net/ISP.htm
Sporadic E is the Earth's aluminum foil beanie for the 'global warming'
sheep. |
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larwe
Guest
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| Posted: Thu Jul 17, 2008 11:35 am Post subject: Re: Good hobbyist VGA camera module? |
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On Jul 16, 5:30 pm, Mike Harrison <m...@whitewing.co.uk> wrote:
| Quote: | I needed one for a forthcoming project & ended up designing my own using a low-res sensor and some
carefully crafted assembler code to catch the data on an ARM processor.
I'm planning on turning this into a product in case there might be a small market out there -
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I was hoping for VGA resolution, since we're currently using QCIF
webcams and wanting an upgrade... the 30K buffer is a bit limiting,
too. Can your device be configured to acquire a 2bpp grayscale image
and send it to me verbatim, preferably over SPI? What's the price
likely to be? |
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larwe
Guest
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| Posted: Thu Jul 17, 2008 11:35 am Post subject: Re: Good hobbyist VGA camera module? |
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On Jul 16, 5:30 pm, Mike Harrison <m...@whitewing.co.uk> wrote:
| Quote: | I needed one for a forthcoming project & ended up designing my own using a low-res sensor and some
carefully crafted assembler code to catch the data on an ARM processor.
I'm planning on turning this into a product in case there might be a small market out there -
|
I was hoping for VGA resolution, since we're currently using QCIF
webcams and wanting an upgrade... the 30K buffer is a bit limiting,
too. Can your device be configured to acquire a 2bpp grayscale image
and send it to me verbatim, preferably over SPI? What's the price
likely to be? |
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| Back to top |
larwe
Guest
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| Posted: Thu Jul 17, 2008 12:10 pm Post subject: Re: AVR, polling INT0 IRQ bit - help? |
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On Jul 16, 7:23 pm, linnix <m...@linnix.info-for.us> wrote:
| Quote: | We are moving off the 169 purely for cost reason. Our new uC (6502)
is 75% off, but it's difficult to port the hardware/software. The 169
|
Energy metering project? (That's what the mega169/329/649 were
designed for). Are you using one of the 6502 variants e.g. from
Sunplus, intended for toy use? Just out of interest, what's your cost
target? We moved to the mega169 because it's significantly under $1.
| Quote: | By the way, our new uC will be die-bounded Chip-On-Board One-Time-
Programmable. Atmel is certainly capable of providing COG and OTP,
but unwilling to do so.
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I can't see that an OTP version of the mega169 would really be cheaper
- since it's not a standard part, there would be big NREs. |
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larwe
Guest
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| Posted: Thu Jul 17, 2008 12:10 pm Post subject: Re: AVR, polling INT0 IRQ bit - help? |
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On Jul 16, 7:23 pm, linnix <m...@linnix.info-for.us> wrote:
| Quote: | We are moving off the 169 purely for cost reason. Our new uC (6502)
is 75% off, but it's difficult to port the hardware/software. The 169
|
Energy metering project? (That's what the mega169/329/649 were
designed for). Are you using one of the 6502 variants e.g. from
Sunplus, intended for toy use? Just out of interest, what's your cost
target? We moved to the mega169 because it's significantly under $1.
| Quote: | By the way, our new uC will be die-bounded Chip-On-Board One-Time-
Programmable. Atmel is certainly capable of providing COG and OTP,
but unwilling to do so.
|
I can't see that an OTP version of the mega169 would really be cheaper
- since it's not a standard part, there would be big NREs. |
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larwe
Guest
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| Posted: Thu Jul 17, 2008 12:23 pm Post subject: Re: Good hobbyist VGA camera module? |
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On Jul 17, 7:45 am, Mike Harrison <m...@whitewing.co.uk> wrote:
| Quote: | Not made decision on pricing yet, but expect to be around the GBP40 mark. First production batch is
starting next week, so assuming I get time to get the software into resonable shape, I expect
availability some time next month.
|
I've bookmarked your site and will look back. The project doesn't
start until the next school semester (September). I briefly considered
asking for a schematic and writing my own firmware, but life's really
too short - I want to buy something canned that "just works"  |
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larwe
Guest
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| Posted: Thu Jul 17, 2008 12:23 pm Post subject: Re: Good hobbyist VGA camera module? |
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On Jul 17, 7:45 am, Mike Harrison <m...@whitewing.co.uk> wrote:
| Quote: | Not made decision on pricing yet, but expect to be around the GBP40 mark. First production batch is
starting next week, so assuming I get time to get the software into resonable shape, I expect
availability some time next month.
|
I've bookmarked your site and will look back. The project doesn't
start until the next school semester (September). I briefly considered
asking for a schematic and writing my own firmware, but life's really
too short - I want to buy something canned that "just works" |
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Peter Petersen
Guest
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| Posted: Thu Jul 17, 2008 12:23 pm Post subject: Re: Multiple USB 1.1 devices in USB 2 Hub speed ? |
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Hello Anton,
| Quote: | If I have a number of USB 1.1 devices plugged into a USB 2 Hub, can I
get the full 12MB/s of each USB 1.1 device via the USB 2 link
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Yes.
| Quote: | Or does the USB 2 link fall back to a 1.1 compatible mode ?
|
No. It would do that with a full speed Hub, but not with a high speed
(2.0) Hub.
All the other posts in this thread are wrong. A USB 2.0 hub is an
intelligent device which will repack the high speed communication coming
from the host and resend it as full/low speed on its downstream ports.
If you want to read about the details, see sections 11.1.1 and 11.14 of the
USB 2.0 Spec (Hub Transaction Translator). USB 2.0 Hubs must be able to
translate between high speed hosts and low/full speed donwstream devices.
| Quote: | So if I need to combine 6 full speed devices into one High speed
channel, I would need something with 6 1.1 host ports and one 2.0
device port.
|
You need one high speed port on your host and one high speed Hub with 6
downstream ports.
Peter |
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Peter Petersen
Guest
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| Posted: Thu Jul 17, 2008 12:23 pm Post subject: Re: Multiple USB 1.1 devices in USB 2 Hub speed ? |
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Hello Anton,
| Quote: | If I have a number of USB 1.1 devices plugged into a USB 2 Hub, can I
get the full 12MB/s of each USB 1.1 device via the USB 2 link
|
Yes.
| Quote: | Or does the USB 2 link fall back to a 1.1 compatible mode ?
|
No. It would do that with a full speed Hub, but not with a high speed
(2.0) Hub.
All the other posts in this thread are wrong. A USB 2.0 hub is an
intelligent device which will repack the high speed communication coming
from the host and resend it as full/low speed on its downstream ports.
If you want to read about the details, see sections 11.1.1 and 11.14 of the
USB 2.0 Spec (Hub Transaction Translator). USB 2.0 Hubs must be able to
translate between high speed hosts and low/full speed donwstream devices.
| Quote: | So if I need to combine 6 full speed devices into one High speed
channel, I would need something with 6 1.1 host ports and one 2.0
device port.
|
You need one high speed port on your host and one high speed Hub with 6
downstream ports.
Peter |
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