ARM boards for low-cost GPSDOs
On Thu, Apr 10, 2014 at 4:40 PM, Chris Albertson
albertson.chris@gmail.comwrote:
- TI sells a "Launch Pad" at a very good price, about $13 and it is VERY
well supported with training materials, software and so on. I'm sure TI
iix taking a loss on these. They can't be making money at $13 This is a
great value.
http://www.ti.com/ww/en/launchpad/launchpads-tivac.html#tabs
edX have been running a course on embedded systems using a TI LaunchPad.
I've been doing it for fun using the TI Stellaris LM4F120 LaunchPad:
https://www.edx.org/course/utaustinx/utaustinx-ut-6-01x-embedded-systems-1172
If that doesn't work, got to www.edx.org and look for courses from
UTAustinX.
It's a pretty good introduction to programming these things, using the Keil
development environment. They have programmed addons to the IDE to grade
your work both in simulation and on real hardware. A bit late to start on
it, but no actual deadlines have passed... yet.
Orin.
On 4/10/14 2:38 PM, Hal Murray wrote:
Does anybody have a favorite low-cost ARM board? I'm looking for a simple
Arduino like setup rather than something that runs Linux. The idea is to get
32 bit counters so a bunch of the recent discussion can be ingnored.
teensy3.1.. ARM Cortex M0 in the context of a Freescale K20 Kinetis
chip. Arduino compatible (uses the IDE, etc.), <$20. 72 MHz clock, etc.
Hi All,
I've used the STM32F4 for a few projects, and was considering it for a
time tagger for a DMTD system. I have a question about the clocking
though that someone may be able to help me with.
The 32F4 (like lots of similar ARMs) uses a PLL to generate the internal
clocks from much lower frequency clock or crystal. Has anyone quantified
the stability of the synthesised clock?
Thanks,
david
On 11/04/2014 8:02 AM, Alberto di Bene wrote:
On 4/10/2014 11:38 PM, Hal Murray wrote:
Does anybody have a favorite low-cost ARM board? I'm looking for a
simple
Arduino like setup rather than something that runs Linux. The idea is
to get
32 bit counters so a bunch of the recent discussion can be ingnored.
==========
I can't recommend warmly enough the Discovery board from STM.
It sports a Cortex ARM M4F that can run at 180 MHz, has a native
IEEE compliant floating point core, 2MB flash and 256 kB RAM,
and a wealth of interesting peripherals on chip, TFT display touch
enabled included. And at 23.52 USD is cheaper than a much
less powerful Arduino...
I implemented on it a fully featured SDR, without using any opsys,
talking directly to the bare metal using the Keil IDE/compiler.
A joy to use. Look here :
http://www.st.com/web/catalog/tools/FM116/SC959/SS1532/LN1848/PF259090
73 Alberto I2PHD
This email is free from viruses and malware because avast! Antivirus
protection is active.
http://www.avast.com
David we may be drifting from Hals thread. So don't want to do that.
I looked at the system and its governed by the xtal they use. Granted its
cheap and totally in an uncontrolled environment. Mine typically is +.79
ppm at 1 Mhz. Semi consistent. Its really easy to bypass that xtal and to
inject some higher quality source and reap those benefits. They have little
pads and such to allow it.
Regards
Paul
WB8TSL
On Fri, Apr 11, 2014 at 7:49 AM, davidh dhooke@gmail.com wrote:
Hi All,
I've used the STM32F4 for a few projects, and was considering it for a
time tagger for a DMTD system. I have a question about the clocking though
that someone may be able to help me with.
The 32F4 (like lots of similar ARMs) uses a PLL to generate the internal
clocks from much lower frequency clock or crystal. Has anyone quantified
the stability of the synthesised clock?
Thanks,
david
On 11/04/2014 8:02 AM, Alberto di Bene wrote:
On 4/10/2014 11:38 PM, Hal Murray wrote:
Does anybody have a favorite low-cost ARM board? I'm looking for a
simple
Arduino like setup rather than something that runs Linux. The idea is
to get
32 bit counters so a bunch of the recent discussion can be ingnored.
==========
I can't recommend warmly enough the Discovery board from STM.
It sports a Cortex ARM M4F that can run at 180 MHz, has a native
IEEE compliant floating point core, 2MB flash and 256 kB RAM,
and a wealth of interesting peripherals on chip, TFT display touch
enabled included. And at 23.52 USD is cheaper than a much
less powerful Arduino...
I implemented on it a fully featured SDR, without using any opsys,
talking directly to the bare metal using the Keil IDE/compiler.
A joy to use. Look here :
http://www.st.com/web/catalog/tools/FM116/SC959/SS1532/LN1848/PF259090
73 Alberto I2PHD
This email is free from viruses and malware because avast! Antivirus
protection is active.
http://www.avast.com
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/
mailman/listinfo/time-nuts
and follow the instructions there.
Hi
Here’s the issue about “big powerful 32 bit ARM processors”….
At the chip level (as in no board, just the bare part to solder down) their are many parts below $1 and some below $0.50 in reasonable quantity (say 10K). It’s hard to find a useful MCU of any sort below $0.25, so the “premium” for an ARM is not very large. Depending on what you need for i/o, the ARM may / may not be lower priced than the alternative. In a lot of cases it is the low price option. There are many flavors of ARM and many competing parts, so doing a full matrix to compare them all is a massive undertaking. Indeed a Coretex M0 with 32K of flash is not the same thing as an M4 or something bigger still. There are a lot of flavors of ARM.
At the semiconductor level, none of the manufacturers are going to state it clearly, but it’s becoming more and more clear. The support for (and enhancement of) chips that are not based on ARM is going to dry up. It’s happening already if you watch the little details. It will be happening more and more as time marches on. It will be very tough for an MCU over about $1.00 a chip (at say 10K pcs) to compete with the ARM parts going forward outside niche markets (like DSP).
No, it’s not going to happen overnight. It will take a number of years for things to work out.
———
So why do a GPSDO on an ARM - They have staying power. The bang for the buck is there. There are a lot of cheap boards out there with them already set up and running on them. Nobody big is going back to leaded parts. Semiconductor guys follow the big users. The future of “home project” work with CPU’s is to use a cheap board rather than a chip. The prices of the boards will just keep coming down, they are not going to go up…. I can’t buy the parts on a $10 board for $30, let alone put them all together.
Pick a board and go with it. Put your stuff on a second board and plug them together. Cheaper, faster, easier than DIY. You get USB / Ethernet / whatever thrown in. With the right board (chip) you get flexible clocks and PLL’s that make the whole process a lot easier.
What’s not to like?
Well yes, you need to dig into a tool chain. They either are free, or are going to be free fairly soon now. There are even web based tools to do the code stuff (mbed). You can’t quite write it for one chip and drop it on another one blindly. You do get locked (a bit) into your chip choice.
All in all, far more advantages than disadvantages.
Bob
On Apr 10, 2014, at 8:11 PM, Chris Albertson albertson.chris@gmail.com wrote:
I'm thinking about good reasons to build a GPSDO using something as big and
powerful as a 32-bit ARM processor. I think the reason is that you are
not really building a GPSDO but some other device that just happens to have
a GPSDO inside of it.
For example you want to build a laser range finder and you need to measure
time of flight delay. You'd need a very good clock and while you are at it
why not discipline the clock with GPS. I could think of some radio
experiments where I would want pairs of receivers with their local
oscillators running in phase but many miles apart, so I'd build a GPSDO
into the radio. The ARM would support running the GPSDO, the bigger
application and also remote access over the network or Internet.
Today people mostly will build a stand alone GPSDO in a dedicated box and
then connect the 10MHZ output to whatever is needed but now as we have
seen, you can build a GPSDO completely in software, if your project already
has a computer then you can run a GPSDO inside an interrupt handler as a
background task. Adding GPSDO functionality to an existing product is
almost trivially simple, just $2 in parts and some software if you already
have a CPU and OCXO as part of your system.
Placing the GPSDO inside the product means the gpsdo can run at a frequency
that is more useful and needs no conversion. So you can have the GPS
control a 23 Mhz crystal if that is what your laser rangefinder needs. Now
that the cost of a GPSDO has fallen to $3 you can build them into
"everything". It no longer needs to be a shared device.
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Bob 100% totally agree and I am seeing the same thing happening. It has to
do with the lower power consumption. When you see Intel scrambling again to
take some share thats the biggest clue there is that a shift is on the way.
But enough of that I said my piece far earlier in the chain. We sure are
lucky to have this stuff on a board to use for what I consider to be
inexpensive. And I don't have to solder the darned things!
Best regards
Paul
WB8TSL
On Sat, Apr 12, 2014 at 12:23 PM, Bob Camp lists@rtty.us wrote:
Hi
Here's the issue about "big powerful 32 bit ARM processors"....
At the chip level (as in no board, just the bare part to solder down)
their are many parts below $1 and some below $0.50 in reasonable quantity
(say 10K). It's hard to find a useful MCU of any sort below $0.25, so the
"premium" for an ARM is not very large. Depending on what you need for i/o,
the ARM may / may not be lower priced than the alternative. In a lot of
cases it is the low price option. There are many flavors of ARM and many
competing parts, so doing a full matrix to compare them all is a massive
undertaking. Indeed a Coretex M0 with 32K of flash is not the same thing as
an M4 or something bigger still. There are a lot of flavors of ARM.
At the semiconductor level, none of the manufacturers are going to state
it clearly, but it's becoming more and more clear. The support for (and
enhancement of) chips that are not based on ARM is going to dry up. It's
happening already if you watch the little details. It will be happening
more and more as time marches on. It will be very tough for an MCU over
about $1.00 a chip (at say 10K pcs) to compete with the ARM parts going
forward outside niche markets (like DSP).
No, it's not going to happen overnight. It will take a number of years for
things to work out.
So why do a GPSDO on an ARM - They have staying power. The bang for the
buck is there. There are a lot of cheap boards out there with them already
set up and running on them. Nobody big is going back to leaded parts.
Semiconductor guys follow the big users. The future of "home project" work
with CPU's is to use a cheap board rather than a chip. The prices of the
boards will just keep coming down, they are not going to go up.... I can't
buy the parts on a $10 board for $30, let alone put them all together.
Pick a board and go with it. Put your stuff on a second board and plug
them together. Cheaper, faster, easier than DIY. You get USB / Ethernet /
whatever thrown in. With the right board (chip) you get flexible clocks and
PLL's that make the whole process a lot easier.
What's not to like?
Well yes, you need to dig into a tool chain. They either are free, or are
going to be free fairly soon now. There are even web based tools to do the
code stuff (mbed). You can't quite write it for one chip and drop it on
another one blindly. You do get locked (a bit) into your chip choice.
All in all, far more advantages than disadvantages.
Bob
On Apr 10, 2014, at 8:11 PM, Chris Albertson albertson.chris@gmail.com
wrote:
I'm thinking about good reasons to build a GPSDO using something as big
and
powerful as a 32-bit ARM processor. I think the reason is that you are
not really building a GPSDO but some other device that just happens to
have
a GPSDO inside of it.
For example you want to build a laser range finder and you need to
measure
time of flight delay. You'd need a very good clock and while you are at
it
why not discipline the clock with GPS. I could think of some radio
experiments where I would want pairs of receivers with their local
oscillators running in phase but many miles apart, so I'd build a GPSDO
into the radio. The ARM would support running the GPSDO, the bigger
application and also remote access over the network or Internet.
Today people mostly will build a stand alone GPSDO in a dedicated box and
then connect the 10MHZ output to whatever is needed but now as we have
seen, you can build a GPSDO completely in software, if your project
already
has a computer then you can run a GPSDO inside an interrupt handler as a
background task. Adding GPSDO functionality to an existing product is
almost trivially simple, just $2 in parts and some software if you
already
have a CPU and OCXO as part of your system.
Placing the GPSDO inside the product means the gpsdo can run at a
frequency
that is more useful and needs no conversion. So you can have the GPS
control a 23 Mhz crystal if that is what your laser rangefinder needs.
Now
that the cost of a GPSDO has fallen to $3 you can build them into
"everything". It no longer needs to be a shared device.
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and follow the instructions there.
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I have to agree. At the hobby level I've been using board level products.
Typically some guy in China buys the chips and any needed passive parts
and builds a PCB. Almost always the PCB will have a row of holes on the
edge to fit a 0.1" header strip. The board with shipping sells cheaper
than the price of the parts. (The Chinese sellers are using private
mailing brokers who can aggregate large numbers of packages onto pallets,
ship the pallets via low cost carries to a warehouse near a US post office.
The packages are zip-code sorted and dropped into the USPO's pre-sorted
bulk-mail system for just a few cents per package.)
I think what prevents many people from using some uP parts is the tools.
In the past they were complex but Arduino fixed that. They made is VERY
easy to get started and really set the bar for others. Everyone else is
catching up. There really WAS a high cost of entry back when you needed
to know how to edit text and send it to a compiler then a loader and burn
PROMs using special prom burner hardware. All that complexity is now gone.
Notice that new Arduino boards are ARM based and if you were foresightful
enough to only use the features that are documented for Arduino your
software can move directly to the new ARM board. Many hobby programmers
should not notice the difference when a CPU is changed. They are writing
in C/C++
Today at the retail level AVR based Arduino is much less expensive. You
can buy one with shipping for under $4 and you can use a 9V "radio battery"
for a power supply. I've bought some for under $3. But, yes some day
ARM will move down into this price point.
On Sat, Apr 12, 2014 at 9:23 AM, Bob Camp lists@rtty.us wrote:
Hi
Here's the issue about "big powerful 32 bit ARM processors"....
At the chip level (as in no board, just the bare part to solder down)
their are many parts below $1 and some below $0.50 in reasonable quantity
(say 10K). It's hard to find a useful MCU of any sort below $0.25, so the
"premium" for an ARM is not very large. Depending on what you need for i/o,
the ARM may / may not be lower priced than the alternative. In a lot of
cases it is the low price option. There are many flavors of ARM and many
competing parts, so doing a full matrix to compare them all is a massive
undertaking. Indeed a Coretex M0 with 32K of flash is not the same thing as
an M4 or something bigger still. There are a lot of flavors of ARM.
At the semiconductor level, none of the manufacturers are going to state
it clearly, but it's becoming more and more clear. The support for (and
enhancement of) chips that are not based on ARM is going to dry up. It's
happening already if you watch the little details. It will be happening
more and more as time marches on. It will be very tough for an MCU over
about $1.00 a chip (at say 10K pcs) to compete with the ARM parts going
forward outside niche markets (like DSP).
No, it's not going to happen overnight. It will take a number of years for
things to work out.
So why do a GPSDO on an ARM - They have staying power. The bang for the
buck is there. There are a lot of cheap boards out there with them already
set up and running on them. Nobody big is going back to leaded parts.
Semiconductor guys follow the big users. The future of "home project" work
with CPU's is to use a cheap board rather than a chip. The prices of the
boards will just keep coming down, they are not going to go up.... I can't
buy the parts on a $10 board for $30, let alone put them all together.
Pick a board and go with it. Put your stuff on a second board and plug
them together. Cheaper, faster, easier than DIY. You get USB / Ethernet /
whatever thrown in. With the right board (chip) you get flexible clocks and
PLL's that make the whole process a lot easier.
What's not to like?
Well yes, you need to dig into a tool chain. They either are free, or are
going to be free fairly soon now. There are even web based tools to do the
code stuff (mbed). You can't quite write it for one chip and drop it on
another one blindly. You do get locked (a bit) into your chip choice.
All in all, far more advantages than disadvantages.
Bob
On Apr 10, 2014, at 8:11 PM, Chris Albertson albertson.chris@gmail.com
wrote:
I'm thinking about good reasons to build a GPSDO using something as big
and
powerful as a 32-bit ARM processor. I think the reason is that you are
not really building a GPSDO but some other device that just happens to
have
a GPSDO inside of it.
For example you want to build a laser range finder and you need to
measure
time of flight delay. You'd need a very good clock and while you are at
it
why not discipline the clock with GPS. I could think of some radio
experiments where I would want pairs of receivers with their local
oscillators running in phase but many miles apart, so I'd build a GPSDO
into the radio. The ARM would support running the GPSDO, the bigger
application and also remote access over the network or Internet.
Today people mostly will build a stand alone GPSDO in a dedicated box and
then connect the 10MHZ output to whatever is needed but now as we have
seen, you can build a GPSDO completely in software, if your project
already
has a computer then you can run a GPSDO inside an interrupt handler as a
background task. Adding GPSDO functionality to an existing product is
almost trivially simple, just $2 in parts and some software if you
already
have a CPU and OCXO as part of your system.
Placing the GPSDO inside the product means the gpsdo can run at a
frequency
that is more useful and needs no conversion. So you can have the GPS
control a 23 Mhz crystal if that is what your laser rangefinder needs.
Now
that the cost of a GPSDO has fallen to $3 you can build them into
"everything". It no longer needs to be a shared device.
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to
and follow the instructions there.
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and follow the instructions there.
--
Chris Albertson
Redondo Beach, California
Hi
I’ve been working with some friends on an ARM based Arduino project. The support for ARM in the Arduino tool chain is still not really up to speed. It’s actually been faster / easier to take the stuff we need over to another board and tool chain than to fight through all of the gotchas within the Arduino / ARM world. The stuff is free / easy just about any way you do it.
At the chip level, the ARM’s have already overtaken many / most of the AVR’s that you would be using.
Bob
On Apr 12, 2014, at 3:23 PM, Chris Albertson albertson.chris@gmail.com wrote:
I have to agree. At the hobby level I've been using board level products.
Typically some guy in China buys the chips and any needed passive parts
and builds a PCB. Almost always the PCB will have a row of holes on the
edge to fit a 0.1" header strip. The board with shipping sells cheaper
than the price of the parts. (The Chinese sellers are using private
mailing brokers who can aggregate large numbers of packages onto pallets,
ship the pallets via low cost carries to a warehouse near a US post office.
The packages are zip-code sorted and dropped into the USPO's pre-sorted
bulk-mail system for just a few cents per package.)
I think what prevents many people from using some uP parts is the tools.
In the past they were complex but Arduino fixed that. They made is VERY
easy to get started and really set the bar for others. Everyone else is
catching up. There really WAS a high cost of entry back when you needed
to know how to edit text and send it to a compiler then a loader and burn
PROMs using special prom burner hardware. All that complexity is now gone.
Notice that new Arduino boards are ARM based and if you were foresightful
enough to only use the features that are documented for Arduino your
software can move directly to the new ARM board. Many hobby programmers
should not notice the difference when a CPU is changed. They are writing
in C/C++
Today at the retail level AVR based Arduino is much less expensive. You
can buy one with shipping for under $4 and you can use a 9V "radio battery"
for a power supply. I've bought some for under $3. But, yes some day
ARM will move down into this price point.
On Sat, Apr 12, 2014 at 9:23 AM, Bob Camp lists@rtty.us wrote:
Hi
Here's the issue about "big powerful 32 bit ARM processors"....
At the chip level (as in no board, just the bare part to solder down)
their are many parts below $1 and some below $0.50 in reasonable quantity
(say 10K). It's hard to find a useful MCU of any sort below $0.25, so the
"premium" for an ARM is not very large. Depending on what you need for i/o,
the ARM may / may not be lower priced than the alternative. In a lot of
cases it is the low price option. There are many flavors of ARM and many
competing parts, so doing a full matrix to compare them all is a massive
undertaking. Indeed a Coretex M0 with 32K of flash is not the same thing as
an M4 or something bigger still. There are a lot of flavors of ARM.
At the semiconductor level, none of the manufacturers are going to state
it clearly, but it's becoming more and more clear. The support for (and
enhancement of) chips that are not based on ARM is going to dry up. It's
happening already if you watch the little details. It will be happening
more and more as time marches on. It will be very tough for an MCU over
about $1.00 a chip (at say 10K pcs) to compete with the ARM parts going
forward outside niche markets (like DSP).
No, it's not going to happen overnight. It will take a number of years for
things to work out.
So why do a GPSDO on an ARM - They have staying power. The bang for the
buck is there. There are a lot of cheap boards out there with them already
set up and running on them. Nobody big is going back to leaded parts.
Semiconductor guys follow the big users. The future of "home project" work
with CPU's is to use a cheap board rather than a chip. The prices of the
boards will just keep coming down, they are not going to go up.... I can't
buy the parts on a $10 board for $30, let alone put them all together.
Pick a board and go with it. Put your stuff on a second board and plug
them together. Cheaper, faster, easier than DIY. You get USB / Ethernet /
whatever thrown in. With the right board (chip) you get flexible clocks and
PLL's that make the whole process a lot easier.
What's not to like?
Well yes, you need to dig into a tool chain. They either are free, or are
going to be free fairly soon now. There are even web based tools to do the
code stuff (mbed). You can't quite write it for one chip and drop it on
another one blindly. You do get locked (a bit) into your chip choice.
All in all, far more advantages than disadvantages.
Bob
On Apr 10, 2014, at 8:11 PM, Chris Albertson albertson.chris@gmail.com
wrote:
I'm thinking about good reasons to build a GPSDO using something as big
and
powerful as a 32-bit ARM processor. I think the reason is that you are
not really building a GPSDO but some other device that just happens to
have
a GPSDO inside of it.
For example you want to build a laser range finder and you need to
measure
time of flight delay. You'd need a very good clock and while you are at
it
why not discipline the clock with GPS. I could think of some radio
experiments where I would want pairs of receivers with their local
oscillators running in phase but many miles apart, so I'd build a GPSDO
into the radio. The ARM would support running the GPSDO, the bigger
application and also remote access over the network or Internet.
Today people mostly will build a stand alone GPSDO in a dedicated box and
then connect the 10MHZ output to whatever is needed but now as we have
seen, you can build a GPSDO completely in software, if your project
already
has a computer then you can run a GPSDO inside an interrupt handler as a
background task. Adding GPSDO functionality to an existing product is
almost trivially simple, just $2 in parts and some software if you
already
have a CPU and OCXO as part of your system.
Placing the GPSDO inside the product means the gpsdo can run at a
frequency
that is more useful and needs no conversion. So you can have the GPS
control a 23 Mhz crystal if that is what your laser rangefinder needs.
Now
that the cost of a GPSDO has fallen to $3 you can build them into
"everything". It no longer needs to be a shared device.
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and follow the instructions there.
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--
Chris Albertson
Redondo Beach, California
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On 4/12/14, 12:50 PM, Bob Camp wrote:
Hi
I’ve been working with some friends on an ARM based Arduino project. The support for ARM in the Arduino tool chain is still not really up to speed. It’s actually been faster / easier to take the stuff we need over to another board and tool chain than to fight through all of the gotchas within the Arduino / ARM world. The stuff is free / easy just about any way you do it.
The teensyduino stuff from PJRC is adding quite a lot to the ARM world
within the Arduino IDE. It is true that for some of the onchip
peripherals, there might not be full support, and you have to do some
register writing, etc.
At the chip level, the ARM’s have already overtaken many / most of the AVR’s that you would be using.
Hi
If you are doing a GPSDO, you probably are playing a lot with things like clock trees and PLL frequencies. There are other free toolchains (often vendor specific) that can make this much easier. Not all ARM’s are the same in terms of clocking, so it’s not a one size fits all sort of thing.
Bob
On Apr 12, 2014, at 7:01 PM, Jim Lux jimlux@earthlink.net wrote:
On 4/12/14, 12:50 PM, Bob Camp wrote:
Hi
I’ve been working with some friends on an ARM based Arduino project. The support for ARM in the Arduino tool chain is still not really up to speed. It’s actually been faster / easier to take the stuff we need over to another board and tool chain than to fight through all of the gotchas within the Arduino / ARM world. The stuff is free / easy just about any way you do it.
The teensyduino stuff from PJRC is adding quite a lot to the ARM world within the Arduino IDE. It is true that for some of the onchip peripherals, there might not be full support, and you have to do some register writing, etc.
At the chip level, the ARM’s have already overtaken many / most of the AVR’s that you would be using.
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