# Member #635630

Member Since: January 6, 2015

Country: United States

• This project proved to be EXACTLY what I needed to make a sine-wave generator for testing the brainwave monitor I'm designing. Here is how I modified it. The line:

``````while ((millis() - Mils) < 1) {};
``````

keeps the frequency correct second by second. And the

``````byte multiplier;
``````

determines the number of cycles per second. "multiplier" can be changed as the program runs, by plugging a grounded jumper into the different Arduino inputs that you have pre-set in this sketch.

``````float in, out;
const int LED = 11;
unsigned long Mils = millis();
byte multiplier = 1;

void setup()
{
pinMode(2, INPUT_PULLUP);
pinMode(3, INPUT_PULLUP);
pinMode(4, INPUT_PULLUP);
pinMode(5, INPUT_PULLUP);
}

void loop()
{
if (digitalRead(2) == LOW)
multiplier = 1;
else if (digitalRead(3) == LOW)
multiplier = 10;
else if (digitalRead(4) == LOW)
multiplier = 20;
else if (digitalRead(5) == LOW)
multiplier = 40;
for (in = 0; in < 6.283; in += (multiplier * 0.006283))
{
while ((millis() - Mils) < 1) {};
Mils += 1;
out = sin(in) * 127.5 + 127.5; // 127.5
analogWrite(LED,out);
}
}
``````

I use it with the first circuit shown at: http://www.wa4dsy.net/robot/active-filter-calc Entering 50 as the number for both input parameters of their calculator, gives the perfect values needed to filter this waveform

No public wish lists :(

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