ADC with ATmega32

[sficht]

Hey guys I am new to the forum and micro controllers in general. Let me begin by saying hello to everyone. Hope all is well.

OK so down to the issue. I am using an ATmega32 16PU

https://www.electro-tech-online.com/custompdfs/2008/04/2503S.pdf

and programming with codevision. What I'm trying to do is a voice modulation type thing. I have a microphone and have put it through a low pass op-amp. I was wondering how exactly the A/D conversion works in this chip and how I can send the data out serially to an off chip D/A (TLC5628IN)

https://www.electro-tech-online.com/custompdfs/2008/04/tlc5628.pdf

so I can output it on a speaker. I also want to do add all sorts of sound effects, but I'm sure I can figure out the code for this(with codevision) if I just know how the whole conversion process is working. Are there any good links I could checkout to learn more about this? or does anyone have any input? If so, it would really help me. Sorry if I sound ignorant, I'm new to all this.

All the best,
Sean

 

[sficht]

Alright so I just looked at my post and realized that it looks a bit rookish (Hence 0 replies). I understand all the hardware/signal transfer behind adc and dac conversions, but I'm not sure how to write the C in codevision. The code for the adc I believe is

var = read_adc(whatever portA pin I want to use)

I guess what I want to know is how (SW'wise) I take 'var' and output it serially, with some given DAC output selection bits attached (e.g. 000 attached as the MSB's selects output A of my DAC chip), so I can reconvert it back to analog. Sorry, the reason I'm having trouble with this is because I'm used to ye ol' vhdl/verilog (basically logic coding) and have only ever worked with limited C. I have to use the ATmega32 for this project, so if ya'll have any advice for me let me know, but if not I'll figure it out .

~Sean

 

[sficht]

Also, I know that the ATmega32 reads the analog into 10bit, so how can I drop that to 8bit?

 

[futz]

Also, I know that the ATmega32 reads the analog into 10bit, so how can I drop that to 8bit?

Simply set the ADLAR bit in ADMUX to left-justify the result and read only ADCH. Ignore ADCL.

The above advice is based on **broken link removed**. You may have to make some small adjustments to suit the Mega32. They'll be real similar though.

 

[eblc1388]

Once you have got the AD data, then you can process it with software.

After that, you need to send it out to the DAC chip TLC5628IN using SPI. I have never used the chip but by reading the data sheet, one can send out the required 12-bit using two 8-bit SPI operations and then "load" the data into the chip.

Or you can use software bit-bang method to send out the data stream instead.

 

[sficht]

Simply set the ADLAR bit in ADMUX to left-justify the result and read only ADCH. Ignore ADCL.

The above advice is based on **broken link removed**. You may have to make some small adjustments to suit the Mega32. They'll be real similar though.

Thanks futz

 

[sficht]

eblc,

let me read over the data sheet again to see if I can figure out exactly how the SPI is going to have to work. I'm feel pretty shaky on using it, though I'd like to use it if I can figure out the op. Don't give up on me though

~Sean

 

[sficht]

Thanks guys

 

[Euronymous]

Hi to all

My name is kike and i'm begginer into Atmega family microcontroler, i need to do a convertion of 3 signals of a ADXL 330 accelerometer. For to do this job, i am using a ATmega32 that have a ADC 8-channel multiplexer, the programing is in assembler. Have someone worked with more than 2 signals?, i am confused of how to programing the both ADMUX and ADCSRA registers.

If someone know how to work with the ADMUX and ADCSRA register, please help me :-( .

see you, and thank you.