kopia lustrzana https://github.com/espressif/esp-idf
28 wiersze
1.5 KiB
Markdown
28 wiersze
1.5 KiB
Markdown
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| Supported Targets | ESP32-S2 |
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| ----------------- | -------- |
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# ULP-RISC-V simple example with GPIO Interrupt:
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This example demonstrates how to program the ULP-RISC-V coprocessor to wake up from a RTC IO interrupt, instead of waking periodically from the ULP timer.
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ULP program written in C can be found across `ulp/main.c`. The build system compiles and links this program, converts it into binary format, and embeds it into the .rodata section of the ESP-IDF application.
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At runtime, the application running inside the main CPU loads ULP program into the `RTC_SLOW_MEM` memory region using `ulp_riscv_load_binary` function. The main code then configures the ULP GPIO wakeup source and starts the coprocessor by using `ulp_riscv_config_and_run` followed by putting the chip into deep sleep mode.
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When the wakeup source pin is pulled low the ULP-RISC-V coprocessor is woken up, sends a wakeup signal to the main CPU and goes back to sleep again.
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In this example the input signal is connected to GPIO0. Note that this pin was chosen because most development boards have a button connected to it, so the pulses to be counted can be generated by pressing the button. For real world applications this is not a good choice of a pin, because GPIO0 also acts as a bootstrapping pin. To change the pin number, check the Chip Pin List document and adjust `WAKEUP_PIN` variable in main.c.
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## Example output
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```
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Not a ULP-RISC-V wakeup, initializing it!
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Entering in deep sleep
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...
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ULP-RISC-V woke up the main CPU!
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Entering in deep sleep
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```
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