I want to send an analog signal to pc through 3.5mm mic or line-in jack then i will read samples by some code. so does the jack have a "standard"?

1- for example, for the same signal with different pc -or even an android device- will i get the same samples?

2- what is the maximum current allowed?

3- will the pins -signal and ground- be the same?


No, different devices with have a slightly different peak voltage or frequency response. But they will be similar enough. An op amp is sufficient to fix any low signal. Or the gain setting on your pc audio card.

The standard exist, and it's headphone or line out. Pretty much standardized based on decades of consumer electronics production

Maximum current is not an issue here. These are logic level signals and not intended to be power sources. The current drawn is milli or micro amps, and power is milli Watts. This is enough to drive headphones that are a killaohm, or megaohm ICs. Anything bigger needs an active/powered amplifier.

Generally speaking, yes. TRS connections have been standardized. Left Right Ground. TRRS connections build an extra conductor, and have two main standards, the Apple and the Everyone Else standard. The two swap the mic and Ground connections.

  • \$\begingroup\$ Thank you thats a good start, by maximum current I meant a safe level when i am sending signal as input to pc through mic-in or line-in on each channel. \$\endgroup\$ – sihs Sep 18 '16 at 17:01
  • \$\begingroup\$ Current is pulled. So whatever the input impedance of the line - in is, is the max safe current. \$\endgroup\$ – Passerby Sep 18 '16 at 19:12
  • \$\begingroup\$ that confused me as i always thought i should deliver current, By looking to this -upload.wikimedia.org/wikipedia/commons/5/57/… do you mean that the voltage+resistor are embedded in card and the mic send the signal just by changing its impedance? and so my circuit should replace the capsule? \$\endgroup\$ – sihs Sep 18 '16 at 23:42

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