Looking for suggestions for simple MCU w/ ADC and DAC

[armstrom]

I'm planning to start a project soon that will rely on a simple MCU to act as the side chain for a dynamics processor. The audio path will be all analog but will be controlled by an MCU.  Much like goldielocks I'm having issues finding an MCU that's "just right". I was hoping I could get some suggestions but those of you in the know...

Here's a list of what I would like to have:
-Modest pin count (don't need a ton of I/O)
-PDIP or SOIC package. (I really don't want to have to learn how to solder some of the crazy fine pitch SMT stuff or any of the QFN/BGA packages, I'm just not that good)
-Built-in ADC with at least three channels
-At least one DAC channel
-Cheap dev board available or the ability to self program with a simple DIY cable
-Decent community support
-Can be programmed with a languaged based on C syntax

I guess that's about it. The part I'm struggling with is finding a low pin count PDIP package that integrates ADC and DAC. So far I've picked up a LaunchPad dev kit from TI just because it's so cheap and it has everything I need except for the DAC (I know I could use the PWM outputs as a crude DAC, and I may try that if I have no other option). I'm trying to find a good DIP based DAC that uses I2C or some other simple serial bus but most of them seem to be SMT.

My plan is to sample the audio using the ADC to determine RMS level and/or frequency and use that to drive a VCA to do various tricks (Compression, tremolo, auto-swell, noise gate, whatever...) I will use any additional ADC channels as control inputs with pots on them to adjust the effects. Sample rate will be much more important that bit depth since I won't be playing back the audio that is captured by the ADC. The DAC will then be used to generate a control voltage for the VCA.

With regard to my background, I've been a Windows software developer for 10+ years so this will be my first MCU project since I was in school so I'm trying to start off with a simpler architecture and a syntax I'm comfortable with.

So, with all of that said, what would you guys suggest? I've seen some mention in other threads of a dsPic chip that has DAC and ADC in a PDIP package but I haven't been able to find a model number for that particular variant.

Thanks in advance!
-Matt

[ExpAnonColin]

Few small MCUs have an on-board DAC that is not a PWM.  It seems like most companies consider it a low priority, especially in the presence of a PWM.  I'd recommend using the PWM (it's quite effective and only really adds a couple of parts) or even an R-2R ladder DAC.  Or, just snag a bigger MCU - generally, they are only marginally more expensive than smaller DIP ones, and no one is going to fuss that you're wasting peripherals.  And, soldering QFP or SSOP is not so bad if you have a good soldering iron and tutorial!

-Colin

[slotbot]

So, with all of that said, what would you guys suggest? I've seen some mention in other threads of a dsPic chip that has DAC and ADC in a PDIP package but I haven't been able to find a model number for that particular variant.

one such model is

dsPIC33FJ64GP802 (available in 28 pin dip) there may be others too but i *think* this is the only DIP package.

product page: http://www.microchip.com/wwwproducts/Devices.aspx?dDocName=en532310

Look up the dspic33 reference and then go to the section on the DAC module, it gives a pretty good overview of the hardware and how it works.

Also many companies also make nice small 8 pin dip DACs that work with SPI no problem. It might even be cheaper/smaller footprint to get a smaller non dsp PIC/atmega whatever have you, and a DAC .

[cloudscapes]

As it's been said, few MCU's in DIP format have integrated DACs (that aren't PWM). I'd much rather use an external DAC (MCP4921 is nice and easy to use) and have the option to choose among many MCUs.

[ExpAnonColin]

one such model is

dsPIC33FJ64GP802 (available in 28 pin dip) there may be others too but i *think* this is the only DIP package.

I had forgotten about those. They would be really interesting if the ADC was also 16 bit.  Then we could fake CD quality with them.  I have never owned a PIC programmer though so I don't know if I'll ever get around to trying them.