- Tue Jun 23, 2015 8:10 pm
#182880
I have some DDS code running on the Due (which is an awesome 32bit beast running at some 96Mhz which makes complex DDS possible). I am generating a 440hz 1.2vpp signal from the DAC pins as evidenced on the scope. I have it going through a 500ohm resistor and .22uF capacitor to filter out the DC level and I see a nice sinusoidal waveform on the scope at the expected frequency (about 2.2ms/per cycle). I have tried to feed that into a LM386 circuit, but either my circuit skills have gotten horrible in the years or the circuits I found on the net just didn't work or I could just have a bad LM386. I'm tired of dealing with building amps though and I have a nice STA540 kit that I built awhile back. I just want to hear output since the next step is going to be mixing several waveforms using additive synthesis. I've also written filter and distortion processors which I also want to test. I can always look at the scope I suppose, but it's more satisfying to hear the sound rather than just see it.
tl/dr Is it safe to put the DAC0/DAC1 outputs of the Arduino Due into the input of an STA540 breakout board? This board has an LM358 configured as unity gain on the input and I'm assuming the high input impedance of the op amp will keep my Due safe. I'm still going to add a 500ohm resistor in series though just to be safe, because I'm paranoid like that. *Output of Due was measured at 1.2vpp
tl/dr Is it safe to put the DAC0/DAC1 outputs of the Arduino Due into the input of an STA540 breakout board? This board has an LM358 configured as unity gain on the input and I'm assuming the high input impedance of the op amp will keep my Due safe. I'm still going to add a 500ohm resistor in series though just to be safe, because I'm paranoid like that. *Output of Due was measured at 1.2vpp