Re: What would you like to see in The Next Chip?
Posted: Tue May 29, 2018 10:09 am
In my view the main thing that needs sorting out for the next chip is the analogue to digital converter (ADC).
The issues with the ADC at present are:
1) Severe non-linearity with 11dB attenuation;
2) With a fixed input voltage, the digital readings vary significantly from one sample to the next (I guess this is due to noise on the reference voltage);
3) Inability to measure down to zero volts (currently only down to about 0.17V depending on attenuation setting);
4) There's no point currently having 11 and 12 bit resolution while there is so much 'noise'.
5) Atmel chips have sample-and-hold but I'm not aware of ESP32 having sample-and-hold. From Wikipedia:
The option with Atmel chips to have an ADC working between zero volts and VDD can be useful, for example with joysticks.
The issues with the ADC at present are:
1) Severe non-linearity with 11dB attenuation;
2) With a fixed input voltage, the digital readings vary significantly from one sample to the next (I guess this is due to noise on the reference voltage);
3) Inability to measure down to zero volts (currently only down to about 0.17V depending on attenuation setting);
4) There's no point currently having 11 and 12 bit resolution while there is so much 'noise'.
5) Atmel chips have sample-and-hold but I'm not aware of ESP32 having sample-and-hold. From Wikipedia:
I wonder whether some users would like flash ADC converters available to give very much faster sampling times, even if the resolution is say only 8 bits.Since a practical ADC cannot make an instantaneous conversion, the input value must necessarily be held constant during the time that the converter performs a conversion (called the conversion time). An input circuit called a sample and hold performs this task . . . .
The option with Atmel chips to have an ADC working between zero volts and VDD can be useful, for example with joysticks.