ATxmega256A3BU Xplained - DAC for Speaker/ Mic/ Wifi Use

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Hello,

 

I recently ordered ATxmega256A3BU Xplained Evaluation board. I was planning to use it to set up VOIP (well, a walkie talkie over wifi ). I saw the XMega A series has an ADC and DAC I could use with a Mic/Speaker. but the starter kit was pretty expensive and it didnt come in a PDIP package, So I went with this board. But I am anxious if it will be able to perform the functions I need it to. I didn't see any mention of DAC or ADC in the description on the website I ordered it from: http://www.digikey.ca/catalog/en... .

 

- Did I make a mistake in buying this board? Should I return this and look for an alternative?

- Considering it has all those features already integrated in it, why is it cheaper than the breakout only board?

 

Am I doing something wrong here? Can someone please explain if I can make it work.

 

Thanks 

This topic has a solution.

Soul

Last Edited: Sun. Nov 6, 2016 - 11:58 PM
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Soulistic wrote:
 I didn't see any mention of DAC or ADC in the description on the website I ordered it from:

 

So why not go straight to the horse's mouth: http://www.atmel.com/tools/XMEGA... - full documentation, including schematics, there

 

 

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Did you happen to click on Datasheets?

 

Greg Muth

Portland, OR, US

Xplained/Pro/Mini Boards mostly

 

Make Xmega Great Again!

 

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I did. No mention of a DAC. found the ADC though. Don't know if it lets me access the features of the chip as is. I mean there is supposed to be a DAC in there, isn't it? http://www.atmel.com/Images/Atme... according to the micro itself it would be the PORTB. but in the hardware guide it says PB0-4 are ADC. However, it's mentioned in the Controller's Man, as PB2-3 can be configured as DACB pins (pg 57, sec 33.1) . Was wondering if my AVR board would be able to do the same? Even though it doesnt say so in the Doc for my board.

'

Soul

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Soulistic wrote:
Don't know if it lets me access the features of the chip as is.

You need to look at the schematics - they will show you exactly what is (and is not) connected, to where, and how.

 

 

Top Tips:

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  3. Wrong baud rate is usually due to not running at the speed you thought; check by blinking a LED to see if you get the speed you expected
  4. Difference between a crystal, and a crystal oscillatorhttps://www.avrfreaks.net/comment...
  5. When your question is resolved, mark the solution: https://www.avrfreaks.net/comment...
  6. Beginner's "Getting Started" tips: https://www.avrfreaks.net/comment...
This reply has been marked as the solution. 
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Soulistic wrote:
Did I make a mistake in buying this board?
No; can either add off-the-shelf mic and speaker amps to it or re-purpose the board.

The xmega256A3BU is well featured with a fair amount of flash and internal RAM with LCD/OLED/etc support.

CodeVisionAVR supports XMEGA; the advanced version adds multiple LCD drivers and graphics functions.

For AVR GCC there's ASF-GFX for the graphics functions on an xmega256A3BU.

Soulistic wrote:
Should I return this ...
No

Soulistic wrote:
... and look for an alternative?
Maybe.

Some of the third party XMEGA128A1 or XMEGA128A1U boards already have mic and/or speaker amps.

A digital mic might be able to be interfaced to an XMEGA without much added circuitry; IIRC those are PCM so would need some thought.

Might be easier to use one of the codec plethora; there's a TI app note for I2S-to-SPI (XMEGA A and AU have SPI DMA).

Soulistic wrote:
- Considering it has all those features already integrated in it, why is it cheaper than the breakout only board?
The STK600 covers a lot of AVR, a "large" motherboard PCB, multiple adapter PCB (AVR mount and routing), and relatively low sales volume.

Soulistic wrote:
Am I doing something wrong here?
Right and wrong depend on context.

Did you do sideways? wink


http://www.atmel.com/tools/XMEGA-A3BUXPLAINED.aspx

http://hpinfotech.ro/index.html (CodeVisionAVR)

http://asf.atmel.com/docs/latest/asf_gfx.html

https://www.olimex.com/Products/AVR/Proto/AVR-PX128A1/ ("audio input", "audio output")

https://www.mattairtech.com/index.php/development-boards/mt-x1s-atxmega128a1-u-usb-development-board.html ("Audio amplifier")

 

"Dare to be naïve." - Buckminster Fuller

Last Edited: Sun. Oct 9, 2016 - 12:17 AM
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Chapter 30 (see post #4) describes the DAC. 12 bit, 2 channel. Ought to be able to do audio. Why do you think there is no DAC?

 

Just because one port provides access to the ADC does not mean that the same port cannot support the DAC. There are (usually) 8 I/O pins in an Xmega/Mega/Tiny port (well, some devices have partial-width ports). Check where the DAC pins are connected on your board. That will tell you what you can and cannot do, DAC-wise. DAC outputs are on MCU pins PB2 and PB3 and are shared with a variety of other functions. So, YOU need to see whether those two pins are brought out, maybe as ADC pins. 

 

Checking the schematic, they ARE brought out as ADCB2 and ADCB3. So, you are in luck and can proceed. No other board needed! By the way, the schematic is provided by link in the Hardware Users Guide.

 

Jim

Jim Wagner Oregon Research Electronics, Consulting Div. Tangent, OR, USA http://www.orelectronics.net

Last Edited: Sun. Oct 9, 2016 - 01:21 AM
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ka7ehk wrote:
 the schematic is provided by link in the Hardware Users Guide.

Also via the link I gave in #2

Top Tips:

  1. How to properly post source code - see: https://www.avrfreaks.net/comment... - also how to properly include images/pictures
  2. "Garbage" characters on a serial terminal are (almost?) invariably due to wrong baud rate - see: https://learn.sparkfun.com/tutorials/serial-communication
  3. Wrong baud rate is usually due to not running at the speed you thought; check by blinking a LED to see if you get the speed you expected
  4. Difference between a crystal, and a crystal oscillatorhttps://www.avrfreaks.net/comment...
  5. When your question is resolved, mark the solution: https://www.avrfreaks.net/comment...
  6. Beginner's "Getting Started" tips: https://www.avrfreaks.net/comment...
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Sorry for the late reply and Thank you so much. The return date was close. Now at least I know I won't have to return this. I will use it to transfer Voice over wifi. I am almost done designing my speaker and microphone PCBs. In the meanwhile, I wanted to get the wifi part sorted out. This is the wifi module I ended up buying. Do you think this would suffice?

 

 

http://www.digikey.ca/product-se...

 

Soul

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www.olimex.com

MOD-WIFI-ESP8266 - Open Source Hardware Board

https://www.olimex.com/Products/IoT/MOD-WIFI-ESP8266/open-source-hardware

...

ESP8266EX is very highly integrated SoC which includes Tensilica's L106 32-bit core processor; SRAM; ...

...

This means only a data UART interface is available.

...

Soulistic wrote:
Do you think this would suffice?
Depends on where the codec function resides (XMEGA or ESP8266)

Uncompressed audio has a significant data rate.

An XMEGA is capable of an audio codec though the ESP8266 will have more compute and RAM capabilities.

https://www.olimex.com/Products/IoT/MOD-WIFI-ESP8266-DEV/open-source-hardware

has an SPI breakout that could be fed from the XMEGA; the XMEGA is an AFE by DMA and DMA over SPI to ESP8266.

There's GCC for ESP8266 :

http://docs.platformio.org/en/stable/platforms/espressif8266.html#olimex

 

"Dare to be naïve." - Buckminster Fuller