Yahoo Groups archive

Lpc2000

Index last updated: 2026-04-28 23:31 UTC

Thread

Eval Card Update

Eval Card Update

2004-02-10 by J.C. Wren

There is now a final rough draft of the eval card schematic at < 
http://tinymicros.com/embedded/LPC210x/lpceval.pdf > 

    The 1-wire interface is not complete.  I'm looking at Robert Adsetts 
requirements for the 1-wire support for his library.  This may require 
moving a couple of I/O pins around, as his code wants to use one of the 
match outputs. 

    The SD/MMC card will support SPI mode, but not the 4 bit wide SD 
mode.  Besides a shortage of I/O, I believe it would be very difficult 
to get the SD 4 bit mode implemented in software to get very close to 
the SPI mode in hardware.

    Missing items are still 'scope ground loops, some points for 
measuring current, some other minor details.  I'll be going over these 
in the next couple days.

    In the case where a SSOP or SOIC part is available, I'll be choosing 
the larger form factor.  I honestly don't know if I can afford to 
produce finished cards, but I will make raw cards available, along with 
the CAD files to produce your own at some place like < 
http://www.4pcb.com/33each >.  Finished cards would require me to have 
enough guaranteed orders to have the boards assembled at a local board 
house, and in low quantities the setup charges would probably eat me 
alive.  I should be able to at least offer all the R's and C's, 
regulators, and other nickle and dime parts. 

    I have managed to order samples for just about every IC on the 
board, excluding regulators.  The parts come from 6 sources: Philips 
(LPC2106), Microchip (MCP23016), Maxim (MAX3227E, MAX3245E, DS18B20, 
DS2401, DS2411, DS1337), Analog Devices (AD7997), National (USBN9603), 
and Ramtron (FM24CL64).   Many people may not care about the AD7997 A/D, 
and the Ramtron DM24CL64 can be replaced with a Microchip 24C64.  
Everything else (so far) is a Digikey item with the exception of the 
SD/MMC connector, which comes from Mouser.

    Any suggestions are welcome.

    --jc

Audio DAC

2004-02-10 by Peter Kuhar

Hello,

Has anyone connected audio DAC to LPC210x?


/Pero

Re: [lpc2100] Eval Card Update

2004-02-10 by Alaric B Snell

J.C. Wren wrote:
>     There is now a final rough draft of the eval card schematic at < 
> http://tinymicros.com/embedded/LPC210x/lpceval.pdf > 

>     I have managed to order samples for just about every IC on the 
> board, excluding regulators.  The parts come from 6 sources: Philips 
> (LPC2106)

You managed to get some LPC2106es? Wow, they're like rocking horse 
droppings around here in the UK!

/me tries again to get a response out of Avnet-Silica...

>     Any suggestions are welcome.

The bridge rectifier on the input is all well and good, but it means 
that any other boards running with this one ought to take power off of 
it, since ground will be a diode drop away. A single diode on the input 
rail, acting as reverse voltage protection rather than reverse voltage 
correction, is what I'd do.

Mmmm, kitchen sink boards... If I had money right now I'd buy one off of 
you :-)

Here's the schematic of the Olimex board, which is apparently working 
fine because they're selling it, in case you want to sanity-check that 
all the necessary lines are pulled up or down and that the capacitors 
and resistors are the right sizes:

http://www.olimex.com/dev/images/lpc-mt-sch.gif

Although they've got a bridge regulator on the input, too!

> 
>     --jc
> 

ABS

Re: [lpc2100] Eval Card Update

2004-02-10 by Leon Heller

----- Original Message -----
Show quoted textHide quoted text
From: "Alaric B Snell" <alaric@...>
To: <lpc2100@yahoogroups.com>
Sent: Tuesday, February 10, 2004 11:11 AM
Subject: Re: [lpc2100] Eval Card Update


> J.C. Wren wrote:
> >     There is now a final rough draft of the eval card schematic at < 
> > http://tinymicros.com/embedded/LPC210x/lpceval.pdf > 
> 
> >     I have managed to order samples for just about every IC on the 
> > board, excluding regulators.  The parts come from 6 sources: Philips 
> > (LPC2106)
> 
> You managed to get some LPC2106es? Wow, they're like rocking horse 
> droppings around here in the UK!

I've got plenty if anyone in the UK wants a couple.

Leon
--
Leon Heller, G1HSM
Email: aqzf13@...
My low-cost Philips LPC210x ARM development system:
http://www.geocities.com/leon_heller/lpc2104.html

Re: [lpc2100] Eval Card Update

2004-02-10 by Alaric B Snell

Leon Heller wrote:

> I've got plenty if anyone in the UK wants a couple.

If you still have four of them in a month I'm going to take you up on that!

> 
> Leon
 >

ABS

Re[2]: [lpc2100] Eval Card Update

2004-02-10 by Peter Kuhar

You can try "Rehar, Tomaz" <Tomaz.Rehar@...>


/Pero

Tuesday, February 10, 2004, 12:20:38 PM, si napisal:
Show quoted textHide quoted text
> ----- Original Message ----- 
> From: "Alaric B Snell" <alaric@...>
> To: <lpc2100@yahoogroups.com>
> Sent: Tuesday, February 10, 2004 11:11 AM
> Subject: Re: [lpc2100] Eval Card Update


>> J.C. Wren wrote:
>> >     There is now a final rough draft of the eval card schematic at <
>> > http://tinymicros.com/embedded/LPC210x/lpceval.pdf > 
>> 
>> >     I have managed to order samples for just about every IC on the
>> > board, excluding regulators.  The parts come from 6 sources: Philips
>> > (LPC2106)
>> 
>> You managed to get some LPC2106es? Wow, they're like rocking horse 
>> droppings around here in the UK!

> I've got plenty if anyone in the UK wants a couple.

> Leon
> --
> Leon Heller, G1HSM
> Email: aqzf13@...
> My low-cost Philips LPC210x ARM development system:
> http://www.geocities.com/leon_heller/lpc2104.html


 
> Yahoo! Groups Links

Re: [lpc2100] Audio DAC

2004-02-11 by Robert Buadu

Here are some thoughts:

I've looked at conecting an I2S audio DAC to the LPC21xx. This is what 
I've concluded.

I2S is a serial interface similar to SPI. The LPC2106 does not have 
hardware support for I2S. We have to implement it in software.

Say we want to output 44.1kHz stereo data. That needs a minimum clock of 
44100 * 16bit * 2 channels = 1411200Hz (1,4MHz).Some chips require a 
minimum clock of clock of 256*fs. That is way too fast. We need to run 
the chip in slave mode and provide a clock for the data.

Lets say our cpu clock is 56448000Hz (56Mhz: 14.112MHz*4). We need to 
output a new sample 40 clock cycles. And we need to toggle the clock 
every 20 clock cycles. The FIQ interrupt haa latency of 7 to 30 cycles. 
So using interrupts will not work too well. Okay if you know that the 
FIQ latency will always be 7 cycles, then it is possible but this 
probably limits what you can do with the processor in normal mode.

One can do away with interrupts and code counting the cycle time of the 
instructions. With this you will more or less have a dedicated parallell 
to I2S converter. One probably can't do very much more with the processor.

A few audio DAC's have a block mode, which does not need a precise 
clock. This allows you to bit-bang the interface. In this case it is 
quite feasible. You only need an interrupt every sample, that is every 
1280 cycles. You then send out a stream of data with the minimum allowed 
clock cycle for block mode. Now, I've not actually tried this so it 
might not work. There was very little info about this mode in the 
datasheet I was reading.

/RB





Peter Kuhar wrote:
Show quoted textHide quoted text
> Hello,
> 
> Has anyone connected audio DAC to LPC210x?
> 
> 
> /Pero
> 
> 
> 
> 
>  
> Yahoo! Groups Links
> 
> 
> 
>  
> 
>

Re[2]: [lpc2100] Audio DAC

2004-02-11 by Peter Kuhar

> Say we want to output 44.1kHz stereo data. That needs a minimum clock of
> 44100 * 16bit * 2 channels = 1411200Hz (1,4MHz).Some chips require a
> minimum clock of clock of 256*fs. That is way too fast. We need to run
> the chip in slave mode and provide a clock for the data.
It's not actualy that fast 256*fs means that clock is 256*44100
11.286600 MHz
A managed to connects philips DAC (in 16 bit left-aligned mode which
is close to I2S) using software, SPI and PWM. But it
takes to much processor time. Just enaught to decode mp3 from internal
flash. But I dont have enoug time left to read  from SD card.

What about connecting DAC to UART using somekind of converter. I was
thinking: 8 pin MCU.

/Pero
Show quoted textHide quoted text
> Peter Kuhar wrote:
>> Hello,
>> 
>> Has anyone connected audio DAC to LPC210x?
>> 
>> 
>> /Pero
>> 
>> 
>> 
>> 
>>  
>> Yahoo! Groups Links
>> 
>> 
>> 
>>  
>> 
>> 


 
> Yahoo! Groups Links

RE: Re[2]: [lpc2100] Audio DAC

2004-02-11 by Jan Szymanski

Have you done any mp3 decoding in software ?
Janek
Show quoted textHide quoted text
-----Original Message-----
From: Peter Kuhar [mailto:peter.kuhar@...] 
Sent: Wednesday, February 11, 2004 16:48
To: Robert Buadu
Subject: Re[2]: [lpc2100] Audio DAC


> Say we want to output 44.1kHz stereo data. That needs a minimum clock
of
> 44100 * 16bit * 2 channels = 1411200Hz (1,4MHz).Some chips require a
> minimum clock of clock of 256*fs. That is way too fast. We need to run
> the chip in slave mode and provide a clock for the data.
It's not actualy that fast 256*fs means that clock is 256*44100
11.286600 MHz
A managed to connects philips DAC (in 16 bit left-aligned mode which
is close to I2S) using software, SPI and PWM. But it
takes to much processor time. Just enaught to decode mp3 from internal
flash. But I dont have enoug time left to read  from SD card.

What about connecting DAC to UART using somekind of converter. I was
thinking: 8 pin MCU.

/Pero







> Peter Kuhar wrote:
>> Hello,
>> 
>> Has anyone connected audio DAC to LPC210x?
>> 
>> 
>> /Pero
>> 
>> 
>> 
>> 
>>  
>> Yahoo! Groups Links
>> 
>> 
>> 
>>  
>> 
>> 



> Yahoo! Groups Links








   



  _____  

Yahoo! Groups Links


*	To visit your group on the web, go to:
http://groups.yahoo.com/group/lpc2100/
  

*	To unsubscribe from this group, send an email to:
lpc2100-unsubscribe@yahoogroups.com
<mailto:lpc2100-unsubscribe@yahoogroups.com?subject=Unsubscribe> 
  

*	Your use of Yahoo! Groups is subject to the Yahoo! Terms of
Service <http://docs.yahoo.com/info/terms/> .

Re[4]: [lpc2100] Audio DAC

2004-02-11 by Peter Kuhar

Wednesday, February 11, 2004, 7:43:43 AM, si napisal:
> MessageHave 
> you done any mp3 decoding in software ?
Yes i used the fixed-point code from helixcode

/Pero

Re: [lpc2100] Audio DAC

2004-02-11 by Robert Buadu

Peter Kuhar wrote:

>>Say we want to output 44.1kHz stereo data. That needs a minimum clock of
>>44100 * 16bit * 2 channels = 1411200Hz (1,4MHz).Some chips require a
>>minimum clock of clock of 256*fs. That is way too fast. We need to run
>>the chip in slave mode and provide a clock for the data.
> 
> It's not actualy that fast 256*fs means that clock is 256*44100
> 11.286600 MHz

Well if you are doing it in software and your clock is 60MHz then it is 
a bit fast.

> A managed to connects philips DAC (in 16 bit left-aligned mode which
> is close to I2S) using software, SPI and PWM. But it
> takes to much processor time. Just enaught to decode mp3 from internal
> flash. But I dont have enoug time left to read  from SD card.

Hey, that's pretty cool.

> What about connecting DAC to UART using somekind of converter. I was
> thinking: 8 pin MCU.
> 

That sounds interesting. If you can find an 8 pin MCU with a uart fast 
enough!

/Robert

Re[2]: [lpc2100] Audio DAC

2004-02-11 by Peter Kuhar

>> What about connecting DAC to UART using somekind of converter. I was
>> thinking: 8 pin MCU.
>> 

> That sounds interesting. If you can find an 8 pin MCU with a uart fast
> enough!

Any sugestions? :)

/Pero

RE: Re[4]: [lpc2100] Audio DAC

2004-02-11 by Jan Szymanski

Thanks, can you give me a link and/or more information, where can I find it, as it
is of interest to me.
Janek
Show quoted textHide quoted text
-----Original Message-----
From: Peter Kuhar [mailto:peter.kuhar@...]
Sent: Wednesday, February 11, 2004 17:50
To: Jan Szymanski
Subject: Re[4]: [lpc2100] Audio DAC

Wednesday, February 11, 2004, 7:43:43 AM, si napisal:
> MessageHave
> you done any mp3 decoding in software ?
Yes i used the fixed-point code from helixcode

/Pero





Re[6]: [lpc2100] Audio DAC

2004-02-11 by Peter Kuhar

https://datatype.helixcommunity.org/mp3dec.html

You must register and use CVS

/Pero

Wednesday, February 11, 2004, 9:17:51 AM, si napisal:
Show quoted textHide quoted text
> MessageThanks, can you give me a link and/or more information, where can I find
> it, as it

> is of 
> interest to me.

> Janek

 

>  -----Original Message-----
> From: Peter Kuhar 
>   [mailto:peter.kuhar@...] 
> Sent: Wednesday, February 11, 
>   2004 17:50
> To: Jan Szymanski
> Subject: Re[4]: [lpc2100] 
>   Audio DAC



> Wednesday, February 11, 2004, 7:43:43 AM, si 
>   napisal:
>> MessageHave 
>> you done any mp3 decoding in software 
>   ?
> Yes i used the fixed-point code from 
>   helixcode

> /Pero






> Yahoo! Groups SponsorADVERTISEMENT



> Yahoo! Groups Links
> To visit your group on the web, go to:
> http://groups.yahoo.com/group/lpc2100/
> \ufffdTo unsubscribe from this group, send an email to:
> lpc2100-unsubscribe@yahoogroups.com
> \ufffdYour use of Yahoo! Groups is subject to the Yahoo! Terms of Service.

Re: Re[2]: [lpc2100] Audio DAC

2004-02-11 by Leon Heller

----- Original Message -----
Show quoted textHide quoted text
From: "Peter Kuhar" <peter.kuhar@...>
To: "Robert Buadu" <lpc2100@yahoogroups.com>
Sent: Wednesday, February 11, 2004 7:20 AM
Subject: Re[2]: [lpc2100] Audio DAC


> >> What about connecting DAC to UART using somekind of converter. I was
> >> thinking: 8 pin MCU.
> >> 
> 
> > That sounds interesting. If you can find an 8 pin MCU with a uart fast
> > enough!

What about SPI? You won't get it on an 8-pin MCU though.

Leon
--
Leon Heller, G1HSM
Email: aqzf13@...
My low-cost Philips LPC210x ARM development system:
http://www.geocities.com/leon_heller/lpc2104.html

Re: [lpc2100] Audio DAC

2004-02-11 by Alaric B Snell

Robert Buadu wrote:

> One can do away with interrupts and code counting the cycle time of the 
> instructions. With this you will more or less have a dedicated parallell 
> to I2S converter. One probably can't do very much more with the processor.
> 
> A few audio DAC's have a block mode, which does not need a precise 
> clock. This allows you to bit-bang the interface. In this case it is 
> quite feasible. You only need an interrupt every sample, that is every 
> 1280 cycles. You then send out a stream of data with the minimum allowed 
> clock cycle for block mode. Now, I've not actually tried this so it 
> might not work. There was very little info about this mode in the 
> datasheet I was reading.

I'm looking at the MAS3587F MP3 codec. You control it with I2C, then 
feed data in and out via an 8-bit parallel interface with 5 control 
bits. I'm thinking that would be quite easy; MP3 data rates are in the 
realms of 128KBit/sec (16KBytes/sec). I can manage to output a byte via 
GPIO every 16,000ths of a second, no problems :-)

There's also the STA013 which, at a pinch, can apparently be fed its MP3 
stream via SPI, but that's a decoder only. Which is probably fine for 
you. Unlike the MAS3587F, though, it generates a serial audio signal 
which needs to be fed into a DAC.

http://www.open-research.org.uk/ARMuC/index.cgi?STA013

Of course, this is no use to you if your source data just inexorably is 
in uncompressed form... If so, have you considered just combining a RAM 
or ROM or whatever your original data source is with the DAC via some 
glue logic in a PLD on its own clock? Perhaps you could make an audio 
buffer device with some RAM, that exposed an SPI interface to the 
LPC21xx for loading up in big chunks?

> 
> /RB
> 

ABS

RE: Re[6]: [lpc2100] Audio DAC

2004-02-11 by Jan Szymanski

Thanks, I didn't have any luck yet with access (although already
registered) , but will keep trying.
As for I2S see
http://www.atmel.com/dyn/resources/prod_documents/doc2646.pdf where it
is done by CPLD
Janek
Show quoted textHide quoted text
-----Original Message-----
From: Peter Kuhar [mailto:peter.kuhar@...] 
Sent: Wednesday, February 11, 2004 19:30
To: Jan Szymanski
Subject: Re[6]: [lpc2100] Audio DAC


https://datatype.helixcommunity.org/mp3dec.html

You must register and use CVS

/Pero

Wednesday, February 11, 2004, 9:17:51 AM, si napisal:
> MessageThanks, can you give me a link and/or more information, where 
> can I find it, as it

> is of
> interest to me.

> Janek

 

>  -----Original Message-----
> From: Peter Kuhar 
>   [mailto:peter.kuhar@...s.si]
> Sent: Wednesday, February 11, 
>   2004 17:50
> To: Jan Szymanski
> Subject: Re[4]: [lpc2100] 
>   Audio DAC



> Wednesday, February 11, 2004, 7:43:43 AM, si 
>   napisal:
>> MessageHave 
>> you done any mp3 decoding in software 
>   ?
> Yes i used the fixed-point code from 
>   helixcode

> /Pero






> Yahoo! Groups SponsorADVERTISEMENT



> Yahoo! Groups Links
> To visit your group on the web, go to:
> http://groups.yahoo.com/group/lpc2100/
>  To unsubscribe from this group, send an email to:
> lpc2100-unsubscribe@yahoogroups.com
>  Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service.





 



   



 
Yahoo! Groups Links

Re: [lpc2100] Audio DAC

2004-02-11 by Robert Buadu

The LPC2106 is powerfull enough to decode mp3. The Helix mp3 code runs 
at 30MHz on the arm7 core, so there is a lot processing power to spare.

If one can find a neat way to drive an Audio DAC and read from say a MMC 
card with the remaining power, you have a nice little mp3 player using a 
minimum number of components.

So I guess we are just trying to be minimalistic. Finding neat solutions 
to problems. Just for the fun of it.

/RB

Alaric B Snell wrote:
Show quoted textHide quoted text
> Robert Buadu wrote:
> 
> 
>>One can do away with interrupts and code counting the cycle time of the 
>>instructions. With this you will more or less have a dedicated parallell 
>>to I2S converter. One probably can't do very much more with the processor.
>>
>>A few audio DAC's have a block mode, which does not need a precise 
>>clock. This allows you to bit-bang the interface. In this case it is 
>>quite feasible. You only need an interrupt every sample, that is every 
>>1280 cycles. You then send out a stream of data with the minimum allowed 
>>clock cycle for block mode. Now, I've not actually tried this so it 
>>might not work. There was very little info about this mode in the 
>>datasheet I was reading.
> 
> 
> I'm looking at the MAS3587F MP3 codec. You control it with I2C, then 
> feed data in and out via an 8-bit parallel interface with 5 control 
> bits. I'm thinking that would be quite easy; MP3 data rates are in the 
> realms of 128KBit/sec (16KBytes/sec). I can manage to output a byte via 
> GPIO every 16,000ths of a second, no problems :-)
> 
> There's also the STA013 which, at a pinch, can apparently be fed its MP3 
> stream via SPI, but that's a decoder only. Which is probably fine for 
> you. Unlike the MAS3587F, though, it generates a serial audio signal 
> which needs to be fed into a DAC.
> 
> http://www.open-research.org.uk/ARMuC/index.cgi?STA013
> 
> Of course, this is no use to you if your source data just inexorably is 
> in uncompressed form... If so, have you considered just combining a RAM 
> or ROM or whatever your original data source is with the DAC via some 
> glue logic in a PLD on its own clock? Perhaps you could make an audio 
> buffer device with some RAM, that exposed an SPI interface to the 
> LPC21xx for loading up in big chunks?
> 
> 
>>/RB
>>
> 
> 
> ABS
> 
> 
> 
> 
>  
> Yahoo! Groups Links
> 
> 
> 
>  
> 
>

RE: [lpc2100] Audio DAC

2004-02-11 by Jan Szymanski

To interface to MMC or SD card is very easy and if you use SPI than very
little of processor power is
needed. I2S can be done with CPLD
<http://www.atmel.com/dyn/resources/prod_documents/doc2646.pdf>
http://www.atmel.com/dyn/resources/prod_documents/doc2646.pdf , but
maybe there is a simpler method.
Janek
Show quoted textHide quoted text
-----Original Message-----
From: Robert Buadu [mailto:robu@...] 
Sent: Wednesday, February 11, 2004 22:03
To: lpc2100@yahoogroups.com
Subject: Re: [lpc2100] Audio DAC


The LPC2106 is powerfull enough to decode mp3. The Helix mp3 code runs 
at 30MHz on the arm7 core, so there is a lot processing power to spare.

If one can find a neat way to drive an Audio DAC and read from say a MMC

card with the remaining power, you have a nice little mp3 player using a

minimum number of components.

So I guess we are just trying to be minimalistic. Finding neat solutions

to problems. Just for the fun of it.

/RB

Alaric B Snell wrote:

> Robert Buadu wrote:
> 
> 
>>One can do away with interrupts and code counting the cycle time of
the 
>>instructions. With this you will more or less have a dedicated
parallell 
>>to I2S converter. One probably can't do very much more with the
processor.
>>
>>A few audio DAC's have a block mode, which does not need a precise 
>>clock. This allows you to bit-bang the interface. In this case it is 
>>quite feasible. You only need an interrupt every sample, that is every

>>1280 cycles. You then send out a stream of data with the minimum
allowed 
>>clock cycle for block mode. Now, I've not actually tried this so it 
>>might not work. There was very little info about this mode in the 
>>datasheet I was reading.
> 
> 
> I'm looking at the MAS3587F MP3 codec. You control it with I2C, then 
> feed data in and out via an 8-bit parallel interface with 5 control 
> bits. I'm thinking that would be quite easy; MP3 data rates are in the

> realms of 128KBit/sec (16KBytes/sec). I can manage to output a byte
via 
> GPIO every 16,000ths of a second, no problems :-)
> 
> There's also the STA013 which, at a pinch, can apparently be fed its
MP3 
> stream via SPI, but that's a decoder only. Which is probably fine for 
> you. Unlike the MAS3587F, though, it generates a serial audio signal 
> which needs to be fed into a DAC.
> 
> http://www.open-research.org.uk/ARMuC/index.cgi?STA013
> 
> Of course, this is no use to you if your source data just inexorably
is 
> in uncompressed form... If so, have you considered just combining a
RAM 
> or ROM or whatever your original data source is with the DAC via some 
> glue logic in a PLD on its own clock? Perhaps you could make an audio 
> buffer device with some RAM, that exposed an SPI interface to the 
> LPC21xx for loading up in big chunks?
> 
> 
>>/RB
>>
> 
> 
> ABS
> 
> 
> 
> 
>  
> Yahoo! Groups Links
> 
> 
> 
>  
> 
> 


Yahoo! Groups Sponsor	

ADVERTISEMENT
 
<http://rd.yahoo.com/SIG=12ch5u24o/M=243273.4510124.5685162.1261774/D=eg
roupweb/S=1706554205:HM/EXP=1076583768/A=1750744/R=0/*http://servedby.ad
vertising.com/click/site=552006/bnum=1076497368914988> Click to learn
more... 	
 
<http://us.adserver.yahoo.com/l?M=243273.4510124.5685162.1261774/D=egrou
pweb/S=:HM/A=1750744/rand=509907347> 	


  _____  

Yahoo! Groups Links


*	To visit your group on the web, go to:
http://groups.yahoo.com/group/lpc2100/
  

*	To unsubscribe from this group, send an email to:
lpc2100-unsubscribe@yahoogroups.com
<mailto:lpc2100-unsubscribe@yahoogroups.com?subject=Unsubscribe> 
  

*	Your use of Yahoo! Groups is subject to the Yahoo! Terms of
Service <http://docs.yahoo.com/info/terms/> .

Re: Audio DAC

2004-02-11 by lpc2100_fan

--- In lpc2100@yahoogroups.com, Peter Kuhar <peter.kuhar@g...> wrote:
> >> What about connecting DAC to UART using somekind of converter. I was
> >> thinking: 8 pin MCU.
> >> 
> 
> > That sounds interesting. If you can find an 8 pin MCU with a uart fast
> > enough!
> 
> Any sugestions? :)
> 
> /Pero

Have no idea whther it is fast enough or not but it is an 8-bit 8-pin
MCU with serial interface. Using an internal oscillator which is
accurate enough to drive the UART in standard baudrates (we did some
tests up to 230.4 kbaud) the LPC903 or LPC908 could do the job. Both
are very similar but have different pinout.
Found this information on the Spoerle website:
http://www.spoerle.com/binaries/1060691817289-903-info.011003.pdf
And more here on Philips:
http://www.semiconductors.philips.com/pip/P89LPC903FD.html
For 908 the info is here:
http://www.semiconductors.philips.com/pip/P89LPC907FD.html
Don't ask me why the link is called 907 ;-)

Neither of these devices can be clocked externally so the max speed
you get is the internal oscillator. Neat little devices though.

Cheers, Bob

Move to quarantaine

This moves the raw source file on disk only. The archive index is not changed automatically, so you still need to run a manual refresh afterward.