Question

How to generate bipolar signl using microcontroller?

Answer 1

Then, one resistor from ADC input to VCC, say 5K, and one resistor from ADC input to GND, 5K as well; then one in series from ext voltage to the ADC input, let's make it 10K: this should work, though probably not "exactly" deploying the full 0-5 range - should do some better math and /or match the resulting values with existing ones.

Answer 2

Answer:

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• Then, one resistor from ADC input to VCC, say 5K, and one resistor from ADC input to GND, 5K as well; then one in series from ext voltage to the ADC input, let's make it 10K: this should work, though probably not "exactly" deploying the full 0-5 range - should do some better math and /or match the resulting values with existing ones.