How to add support for ADC when that option is not available in uC

[titusece]

Hello,
I have a requirement to read analog voltage from Microprocessor LINEIN pin (Line Input for audio jack)
As i.MX8 doesn't have ADC i would like make use LINEIN pin to send analog voltage (0 to 3.3) and want to get as digital value by reading codec registers.
Is it possible ? sharing any insights would be great.
Thanks for the help.

 

[BradtheRad]

need to find 25%, 50%, 75% and 100% of battery level (3.7V)

In case you want a visual indicator...

Here's a bargraph circuit that abruptly turns led's on or off. Transistor networks perform the same job as a 3914 IC.

I found the schematic below at ElectronicDesign website (before they reworked the article, breaking the link to the schematic):

www.electronicdesign.com/technologies/displays/article/21773647/recursive-circuit-for-bargraph-led-displays-and-shunt-voltage-regulators

Notice supply voltage must reach 1.8 V in order to light the first led.
4.2V is typical charging voltage for a Li-ion cell.
You can add duplicate stages to obtain finer resolution.

 

[Akanimo]

Hi,

In the DART_MX8M_PLUS picture that you posted in Post #4, the diagram shows connections for line in audio jack and headphone audio jack. Are those not supposed to be analog audio signals?

I'd take a look at the datasheet.