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33 lines
1.2 KiB
Markdown
33 lines
1.2 KiB
Markdown
| Supported Targets | ESP32-S2 | ESP32-S3 |
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| ----------------- | -------- | -------- |
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# ULP-RISC-V ADC Example
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This example demonstrates how to use the ULP-RISC-V coprocessor to poll the ADC in deep sleep.
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The ULP program periodically measures the input voltage on EXAMPLE_ADC_CHANNEL (by default ADC1 channel 0, GPIO1 on both ESP32-S2 and ESP32-S3). The voltage is compared to an upper threshold. If the voltage is higher than the threshold, the ULP wakes up the system.
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By default, the threshold is set to 1.75V, approximately.
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In this example, you need to connect a voltage source (e.g. a DC power supply) to the GPIO pin corresponding to the ADC channel specified in `ulp/example_config.h` (see the macros defined on the top of the header file). Feel free to modify the channel setting.
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### Hardware Required
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* A development board with a SOC which has a RISC-V ULP coprocessor (e.g., ESP32-S2 Saola)
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* A USB cable for power supply and programming
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## Example output
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Below is the output from this example.
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```
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Not a ULP-RISC-V wakeup (cause = 0), initializing it!
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Entering in deep sleep
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ULP-RISC-V woke up the main CPU
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Threshold: high = 2000
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Value = 4095 was above threshold
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Entering in deep sleep
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```
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