* Remove voltage buffer Opamp after TL431PK because it may oscillate
* Replace TL431PK with TL431LI. Stabilized by very large capacitance (> 10uF)
* Add panic passives to differential amplifier in order to avoid oscillaton. Values as they are now should work.
* Remove external ADC. Tests with version v1.1 show that the precision of the STM's ADC is sufficient, (once all oscillations are damped by modifying the circuit)
* Power whole OpAmp circuit with 3.3 volts in order to eliminate the need for the clamping diode at the ADC pin. This diode showed a high reverse current over temperature, which affected the measurement.
Mario Hüttel
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