37 lines
1 KiB
Markdown
37 lines
1 KiB
Markdown
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# ULP ADC Example
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This example demonstrates how to use the ULP coprocessor to poll ADC in deep sleep.
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ULP program periodically measures the input voltage on GPIO34. The voltage is compared to two thresholds. If the voltage is less than the low threshold, or higher than the high threshold, ULP wakes up the system.
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By default, thresholds are set to 1.35V and 1.75V, approximately.
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Average current drawn by the ESP32 in this example with the default configuration (10Hz measurement period, 4x averaging) is 80 uA.
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## Example output
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Below is the output from this example. GPIO15 is pulled down to ground to supress output from ROM bootloader.
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```
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Not ULP wakeup
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Entering deep sleep
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Deep sleep wakeup
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ULP did 1531 measurements
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Thresholds: low=1500 high=2000
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Value=973 was below threshold
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Entering deep sleep
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Deep sleep wakeup
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ULP did 2 measurements
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Thresholds: low=1500 high=2000
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Value=0 was below threshold
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Entering deep sleep
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Deep sleep wakeup
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ULP did 2 measurements
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Thresholds: low=1500 high=2000
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Value=0 was below threshold
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Entering deep sleep
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```
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