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I am not using potentiometer like most video or print online. I am using bike grip/hall throttle, its range is 0.8V to 4.3V.

Instead of:

[0V = 000 ADC value] [5V = 255 ADC value]

I want:

[0.8V = 000 ADC value] [4.3V = 255 ADC value]

What ADC do I need ??? How do I wire???

NOTE: Before leaving comment...the video I reference below shows the author achieving 2V-3V (start video at 2:46). I want 0.8V to 4.3V. If you don't have people skills or can't answer my question...please don't leave comments... I am not as smart as some of you.

[ My research so far ]:

(1) How to use Differential Voltage Input ADC's

(2) What is a differential ADC?

  • Forum quote/Peter Gibson:

  • A differential ADC shifts the lower reference from 0V to some other value - either a user input - - - on a second analog input, or a internal reference. What is a differential ADC?

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    \$\begingroup\$ You are shouting. Why wouldn't you just use a 10 or 12 bit ADC and scale the reading digitally? \$\endgroup\$
    – Spehro Pefhany
    Apr 8 '20 at 3:23
  • \$\begingroup\$ In a word, no. Because what you are asking for has nothing to do with a differential ADC, in concept or in hardware. I am quite sure you do not know what a differential ADC actually does. \$\endgroup\$
    – DKNguyen
    Apr 8 '20 at 3:29
  • \$\begingroup\$ Go with what Spehro Pefany said. Your signal is not differential. It sounds to me like some form of variable resistor. If your using a microcontroller with a builtin ADC, use that one with calibration. \$\endgroup\$
    – GB - AE7OO
    Apr 8 '20 at 4:09
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    \$\begingroup\$ STOP SHOUTING AT US. \$\endgroup\$
    – Solar Mike
    Apr 8 '20 at 4:15
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    \$\begingroup\$ @Huisman you can be excluded from whatever you want. \$\endgroup\$
    – Solar Mike
    Apr 8 '20 at 5:56
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The easiest and most reasonable approach to reach the desired reading is to offset them by software.

On a 5V, 8-bit ADC, each value is 0.019V. So a reading of 0.8V would be "42". You can add this in software to subtract, for example if you are reading 0.8V, you would get 42 -42 = 0

A Single Ended ADC can measure a voltage on its input terminal between ground and Vref. For example: To measure a light sensors output, or a potentiometer output, a Single-Ended ADC is used.

A differential ADC is used to measure the difference between the terminals, for example: To measure current, usually a sense resistor is used and a differential ADC is connected to both resistor pins, to measure the voltage drop over the resistor.

For your application a standard single-ended OR Differential will work. If you use a differential one, just connect the negative input to ground.

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If you were using an Arduino environment, the map() function would be very useful.

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