Same sensor. 0dbm is the DC level.

First graph is TI ADS1242 24 bit delta-sigma:



The second is using the built-in 12 bit SAR A/D of the PIC18F65K90:

 

I maybe blind but they both look close
the top one is a bit better tho.

 

I maybe blind but they both look close
the top one is a bit better tho.

Perhaps. But is it $5.52 better?

 

Don't look like it you could probably make the pic18F65K90 even look better

 

Don't look like it you could probably make the pic18F65K90 even look better

One can always make these things better by trading fast response time for lower noise. In this case, I made all things equal except the hardware. I was expecting seriously degraded performance by dropping from 24 to 12 bits. It doesn't happen often, but I was wrong.

 

I would think the PIC would save even more tho in cost by less needed parts.

I was just thinking today I looked at some older PIC's with 8 bit adc I was think man I had some give a good output over sampling.

But I played with a old adc 8 bit chip I2C and it took 10 or so parts to get it up to par where it should be.

The 24 bit sounds good but with your post it really looks like a the pic could be a winner.

 

Your idea of "cool" is a lot different than mine!

 

Your idea of "cool" is a lot different than mine!

I don't know your background...but if you had done any significant DSP in the past, you'd understand why I think these graphs are cool.

 

I a side note have you tried out any of the DAC on a pic the sample code for the 5 bit outputs a good sine wave.
I was hoping to find a maybe 10 bit on one.

DSP yell guess that's why I thought it was cool too been reading up on that I want make a DSP signal generator

 

I a side note have you tried out any of the DAC on a pic the sample code for the 5 bit outputs a good sine wave.
I was hoping to find a maybe 10 bit on one.

Are you speaking Kentuckian? I'm having a hard time understanding you.

 

Yell got get that out of me lol

Have you ran into 10 bit DAC on a PIC chip 16f or 18f chip.

 

Yell got get that out of me lol

Have you ran into 10 bit DAC on a PIC chip 16f or 18f chip.

I don't do much analog out. I have a project that I am working that will use an Analog Devices AD5683. I needed 16 bits, so a PIC D/A wasn't an option.

 

Re: Post #9

Like some others (?) I am not sure I understand. I have have used the 5-bit DAC on a 12F1840 and got results acceptable to me creating some waveforms. Here's a burst of four "exponential decay" at about 500 kHz:


Probably a lot of artifact in that receiver.

 

I am not a DSPer..... joey.......is your point that you achieved close to the same resolution with the 12 bit pic, of that of the 24 bit delta?

It sure looks close to me.....but I,m not a DSPer.

 

A PWM DAC can take you >> 10 bits.

Dithering an 8 bit DAC can get you to 10 bits -

http://www.cypress.com/file/136326/download

http://www.cypress.com/file/135131/download

Regards, Dana.

 

...is your point that you achieved close to the same resolution with the 12 bit pic, of that of the 24 bit delta?

Effectively, yes.

 

joey....you're a 1%er. I'm a 20%er. I have to add a lot of fudge to my circuits.

 

joey....you're a 1%er. I'm a 20%er. I have to add a lot of fudge to my circuits.

Yeah. Silver spoon and all that...

 

1% tolerance components......not the liberal crap.

 

It's funny: this isn't all that hard to do. But it can't be done in C (at least not without a much more capable MCU), which is why many don't.