Microcontroller; any suggestions?

[Dala Dahlgren]

I am trying to find a suitable microcontroller for a hobby-project.

For my project I need an Ethernet-connector, one ADC and one DAC.
Are there any microcontrollers availabel wich have these three features?
I have found a couple with Ethernet and ADC but not with a DAC...

Have anybody got a any good suggestions for such a microcontroller?

 

[[email protected]]

I am trying to find a suitable microcontroller for a hobby-project.

For my project I need an Ethernet-connector, one ADC and one DAC.
Are there any microcontrollers availabel wich have these three features?
I have found a couple with Ethernet and ADC but not with a DAC...

Have anybody got a any good suggestions for such a microcontroller?

Why do you explicitly need ethernet ..?
ADC/DAC below 10 kHz is avail on many MCUs these days afaik.

What communications range do you need?, speed?, accurency?, reliability?


SPI-Ethernet:
http://www.microchip.com/enc28j60

AVR/ATtiny15
A/D, PWM

Use PWM to make D/A with delta sigma?


(I would welcome other ppls opinion on these choices..)

 

[Dala Dahlgren]

Why do you explicitly need ethernet ..?

I wanted to make a small "IP-phone" for fun. The "phone" will need a ADC/DAC
to record/replay speech, and I want to use it on an Ethernet.
So what I am looking for is a microcontroller wich can get the job done
without any external ic's.

And, yes, I know that it would be a lot easier just to use my PC for this
task, but again, this "phone" something I want to make for fun...

 

[Luhan]

I am trying to find a suitable microcontroller for a hobby-project.

For my project I need an Ethernet-connector, one ADC and one DAC.
Are there any microcontrollers availabel wich have these three features?
I have found a couple with Ethernet and ADC but not with a DAC...

Have anybody got a any good suggestions for such a microcontroller?

Dont pic (no pun intended) out a microcontroller for just one project.
There is a large learning curve for any of them; also, you need to get
a development set up.

Choose one you think is the most generally useful - it will pay off in
the long run.

Luhan

 

[Luhan]

I wanted to make a small "IP-phone" for fun. The "phone" will need a ADC/DAC
to record/replay speech, and I want to use it on an Ethernet.
So what I am looking for is a microcontroller wich can get the job done
without any external ic's.

And, yes, I know that it would be a lot easier just to use my PC for this
task, but again, this "phone" something I want to make for fun...

Be sure the publish the results when you are done. I have almost 40
years design experience and would think twice about trying this myself.

Luhan

 

[Dala Dahlgren]

"Luhan"

Be sure the publish the results when you are done. I have almost 40
years design experience and would think twice about trying this myself.

Maybe I am a bit optimistic?
But why do you mean I should "think twice"; is this a bigger task than I
should be able to handle as a hobby-project?
I'm thankful for any input; I am not a pro like you...

 

[[email protected]]

I wanted to make a small "IP-phone" for fun. The "phone" will need a ADC/DAC
to record/replay speech, and I want to use it on an Ethernet.
So what I am looking for is a microcontroller wich can get the job done
without any external ic's.

And, yes, I know that it would be a lot easier just to use my PC for this
task, but again, this "phone" something I want to make for fun...

I guess implementing the VoIP stack completly in a MCU might be a challenge.
But if your willing to shave your spec down a bit it might just work.
Setup two software loops possible triggered by external oscillator (irq on
logic level change). Collect data under X seconds. Then have it transmitted.
And in the other loop for every packet received set every byte to the pwm
correspondingly.

If your willing to go fpga instead the challenge might be easier

 

[Rich Grise]

Be sure the publish the results when you are done. I have almost 40
years design experience and would think twice about trying this myself.

Well, with this:
http://www.itee.uq.edu.au/~peters/xsvboard/stack/stack.htm
(or similar:
http://www.google.com/search?q=VHDL+TCP/IP+Stack )
and some delta-sigma (sigma-delta?) on the same chip, it actually sounds
doable. ;-)

Cheers!
Rich

 

[Rich Grise]

"Luhan"


Maybe I am a bit optimistic?
But why do you mean I should "think twice"; is this a bigger task than I
should be able to handle as a hobby-project?
I'm thankful for any input; I am not a pro like you...

Something like this?
http://www.beyondlogic.org/etherip/ip.htm
found on:
http://www.google.com/search?&q=Microprocessor+with+tcp/ip

Good Luck!
Rich

 

[Rich Grise]

I guess implementing the VoIP stack completly in a MCU might be a challenge.
But if your willing to shave your spec down a bit it might just work.
Setup two software loops possible triggered by external oscillator (irq on
logic level change). Collect data under X seconds. Then have it transmitted.
And in the other loop for every packet received set every byte to the pwm
correspondingly.

If your willing to go fpga instead the challenge might be easier

So, speaking of TCP/IP on an fpga, if someone did that, what would be the
recommended interface to, say, cat5?

Thanks,
Rich

 

[[email protected]]

I guess implementing the VoIP stack completly in a MCU might be a challenge.
But if your willing to shave your spec down a bit it might just work.
Setup two software loops possible triggered by external oscillator (irq on
logic level change). Collect data under X seconds. Then have it transmitted.
And in the other loop for every packet received set every byte to the pwm
correspondingly.

If your willing to go fpga instead the challenge might be easier

[/QUOTE]

So, speaking of TCP/IP on an fpga, if someone did that, what would be the
recommended interface to, say, cat5?

You got to have a PHY (like Intel LXT972M) which essentially translates
between 4 bits LVTTL and baseband ethernet.
After the PHY comes 1:1 signaltransformer and various passive components.

However I suspect it's possible to interface 10 Mbps FD with an electrical hack
useing LVTTL I/O's. Not verified thoe. It would however be very touchy to any
mishaps, but cheap!

And the PHY needs a 25 MHz 50 ppm crystal.

 

[David]

I am trying to find a suitable microcontroller for a hobby-project.

For my project I need an Ethernet-connector, one ADC and one DAC.
Are there any microcontrollers availabel wich have these three features?
I have found a couple with Ethernet and ADC but not with a DAC...

Have anybody got a any good suggestions for such a microcontroller?

You're not likely to find such a combination - relatively few micros
with Ethernet have an ADC (high speed digital and good analogue don't go
well together in the same device), and few micros of any kind have a
DAC. However, a Coldfire 52233 has a 100 MBit Ethernet, including the
PHY, and 8 channels of ADC. The PWM timers might be good enough
resolution for your DAC outputs - otherwise you want a SPI bus DAC.