pvvx / bl702_adc_test

USB ADC 16 bits (averaging) test BL702

bl702_adc_test

USB ADC 16 bits (averaging) test BL702

XT-ZB1Kit

To operate USB BL702C, it is necessary to cut the wire in the area of contact (16) CH340C and solder the wire connecting contact (2) AMS1117-3.3 and contacts (4, 16) CH340C.

• ADC - GPIO_9 (mark D9)
• DAC - GPIO_17 (mark D17)

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XT-ZB1Kit Tests USB ADC-DAC, SDK v2.0

src/sdk2/project_bl702.bin - Test Firmware

TestsTools/adc/wso_adcs.html - ADC data reception via USB

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DAC steps test on ADC (20 ksps, real 15 bits):

ADC scale 16 bits (0..65535)

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Checking the ADC (20 ksps 16 bits) to GND through a resistor with a 1 uF electrolytic capacitor and checking with switching on to the INA199A1 output:

ADC scale 16 bits (0..65535)

To INA199A1

ENOB: 14,93 Bits

SNR: 91,63 dB

To GND

ENOB: 15.16 Bits

SNR: 93.02 dB

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Checking the ADC (100 ksps 14 bits) to GND through a resistor with a 1 uF electrolytic capacitor:

ADC scale 14 bits (0..16383)

ENOB: 13.89 Bits

SNR: 85.38 dB

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Comparison with a linear function

Nonlinearity and Noise