Generate a sawtooth wave with 8kHz frequency

Using Arduino Project Guidance
21

sawtooth_aliased
sawtooth_aliased968×526 61.2 KB

limit = 8192, step = 486

22

Like I said

and limit is 4095. You read the datasheet, didn't you?

23

Yes, I read it several times. But you know I'm a neophyte and I didn't get the point immediately. U tell me to try those values and I wanted to show u the results. That's it

24

A value above 4095 is not accepted.

From the datasheet for MCP4821 - SPI interface with support for 20 MHz clock, fast setup time of 4.5 µs.
According to these data, even with a faster microcontroller you will hardly achieve 8 kHz at a full range of 4096 steps because the DAC itself is not fast enough.

1 Like
25

Hi guys,
After a few die and retry, I finished by got a pretty smooth saw tooth wave with those values:

void loop()
{
  // high-res triangular wave
  for (int i = 0; i < 512; i += 16)
  {
    // setOutput(0, GAIN_2, 1, i);
    setOutput(i);
  }
}

BUT ! I need to amplify the signal I think.

Thanks for all of ur responses.

image
image960×480 52.2 KB

26

Why didn't you just use discrete elements? Like transistors, timer 555 or Op Amp's.

27

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