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About vivitern

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  1. I have a microphone whose output needs to be limited to 0V-5V. The microphone itself should be picking up audio from its environment (such as a living room). Later, specific signals will be identified from the audio stream that the microphone is picking up. The output of the microphone will lead into an analog input pin of a microcontroller which will do all of the signal analysis. But for now, all I'm focusing on is the microphone. I've done some googling and have discovered auto-gain amplifiers that seem to be able to adjust their gain depending on what the output voltage is. If the out
  2. I have the following circuit which I would like to use to connect a MIDI enabled device. I am not getting any signal on pin 5, could it be because the resistor from the base to ground in too small? I am not sure how to calculate it from the datasheet. Update #1 I have replaced the opto-isolator, tested the input using an LED TLHB4201: http://www.kynix.com/Detail/3877/TLHB4201.html and could see the LED light up indicating current flows in the MIDI loop. I have placed a scope probe on the output of pin 5 of the device. pin 6 is now not connected to anything. Normally (idle) the
  3. I'm building an adapter to connect an RJ9 headset output to a 3.5mm jack output(TRRS, mic KY379-SPV1840LR5H-B: http://www.kynix.com/Parts/3439/SPV1840LR5H-B.html included). I have designed it so far to use DG409 (4:1) analog multiplexers to choose what lines are connected to what (for example Pin 1 on the RJ9 connector will be connected to the Sleeve of the 3.5mm jack (TRRS). This is done by connecting one of the AUX outputs to the 1 side and choosing which of the 4 outputs to output to. NOTE: the DG409's that I'm using have two MUX's in one chip so I'm basically grounding all the inputs/
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