关于ADC采样率

[cjs3187607]

Hi,
我在手册里找不到ADC采样率的相关信息，在论坛里有看见帖子说是6K Hz ，这个6KHz 是12Bit采样时最大采样率吗？各Bit采样时，最大采样率是多少呢？

[Archibald]

Google translation of original post from Chinese:

I can not find the ADC sampling rate in the manual information, in the forum to see the post said to be 6K Hz, this 6KHz is 12Bit sampling the maximum sample rate? What is the maximum sample rate for each bit sample?

I am using the Arduino IDF. If I use the Arduino instruction . . . . . .

Code: Select all

v[z] = analogRead(34);

. . . . . (where 'v' is a uint16_t array indexed by 'z'), it takes 9.5µs.

If I use the ESP-IDF instruction with default 12 bit resolution. . . . . .

Code: Select all

v[z] = adc1_get_raw(ADC1_CHANNEL_6);

. . . . . it takes 36.5µs.

I hope someone can explain the reason for that!

ESP_Sprite has written (link):

The bandwidth of the ADC just is more-or-less 6KHz if you want a linear frequency response.

I take 6kHz to mean the analogue bandwidth, not the sample rate.

Usng the Arduino instruction 'analogRead', I am sampling a 40kHz sqaure wave at a sample rate of just over 100kHz and seem to be getting good digital values. I therefore question whether 6kHz is correct.

Note ESP32 ADCs are badly affected by noise.

[cjs3187607]

Google translation of original post from Chinese:

I can not find the ADC sampling rate in the manual information, in the forum to see the post said to be 6K Hz, this 6KHz is 12Bit sampling the maximum sample rate? What is the maximum sample rate for each bit sample?

I am using the Arduino IDF. If I use the Arduino instruction . . . . . .

Code: Select all

v[z] = analogRead(34);

. . . . . (where 'v' is a uint16_t array indexed by 'z'), it takes 9.5µs.

If I use the ESP-IDF instruction with default 12 bit resolution. . . . . .

Code: Select all

v[z] = adc1_get_raw(ADC1_CHANNEL_6);

. . . . . it takes 36.5µs.

I hope someone can explain the reason for that!

ESP_Sprite has written (link):

The bandwidth of the ADC just is more-or-less 6KHz if you want a linear frequency response.

I take 6kHz to mean the analogue bandwidth, not the sample rate.

Usng the Arduino instruction 'analogRead', I am sampling a 40kHz sqaure wave at a sample rate of just over 100kHz and seem to be getting good digital values. I therefore question whether 6kHz is correct.

Note ESP32 ADCs are badly affected by noise.

Thanks for your timely help。