Post Created date
FFT basic question
Looks like all FFT roads lead to elm-chan. :) I have seen that site before and will look at it once more. So looks like all I need is sampling frequency and number of FFT points...
Friday, 19 March 2010 - 13:36
ADC averaging question
Bob, I think it is using 1kHz * 28 = 28ksps as the sample rate. Does that make sense?
Thursday, 18 March 2010 - 23:17
ADC averaging question
Cliff, I mean the delay to transfer from ADC to AVR through SPI. But as you mentioned I agree that this won't be a problem. Bob, I am using a 14.746MHz crystal with a prescalar...
Thursday, 18 March 2010 - 04:06
ADC averaging question
Yes. Good old Nyquist.. :) One of the reasons to use only the AVR was to minimize components and improve reliability. Quote: If you use 2 bytes of SPI per sample, that means you "...
Wednesday, 17 March 2010 - 13:15
ADC averaging question
@Cliff, I will be looking at an external ADC. What are some good chips I could use for this? Will the ADC interface to the AVR (SPI,I2C,etc.) slow down my overall sample rate? @...
Tuesday, 16 March 2010 - 02:42
ADC averaging question
Thanks, Jim. I will try that. @Steve, I completely understand your point and it is a valid one. I am only trying to get rid of the noise at a minimum loss of accuracy while still...
Monday, 15 March 2010 - 11:53
ADC averaging question
Ok I tried this: volatile unsigned char flag; volatile uint16_t sum = 0; volatile uint8_t filtered_value = 0; volatile uint8_t i; volatile unsigned char count_1 = 0; ISR(...
Monday, 15 March 2010 - 02:59
ADC averaging question
Quote: How are you seeing those apparent ASCII numbers & spaces when youa re only dumping a binary 8-bit value? I am using realterm. It looks like a good program. So I am...
Monday, 15 March 2010 - 02:19
Question regarding ADC range for Atmega168
Using 5V as reference, 25 would represent 0.5V and 230 would represent about 4.5V. The 0.5V in the GND may explain the 4.5V you see for the VCC. Do you have a capacitor at the ADC...
Wednesday, 10 March 2010 - 13:57
Books/resources on embedded development with XMega
Also as a side note make sure you also look at the errata section in any XMega datasheet. I am thinking of starting on the XMega too, but the forum here pointed me to the errata...
Wednesday, 10 March 2010 - 13:50
Capturing high frequency signals with AVR ADC
It is more on the reproduction side. I need to capture all of the input sine wave. I agree that life would have been much easier if I had to just detect the zero crossings, or...
Tuesday, 9 March 2010 - 00:10
Capturing high frequency signals with AVR ADC
You guys are right, I meant the 200 ksps as the maximum ADC sampling rate. Is there a chart that shows the sampling frequency vs. number of bits that can be used? If there isn't...
Monday, 8 March 2010 - 15:06