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@@ -254,9 +254,9 @@ You can define the defaults for jack, spkfault leds at compile time but nvs para
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### GPIO expander (not fully validated yet)
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It is possible to add GPIO expanders using I2C bus. They should mainly be used for buttons but they can support generic-purpose outputs as well. These additional GPIOs can be numbered starting from an arbitrary value (40 and above as esp32 has GPIO 0..39). Then these new "virtual" GPIOs from (e.g) 100 to 115 can be used in button configuration, set_GPIO or other config settings.
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-Each expander (ONLY ONE FOR NOW) can support up to 32 GPIO. To use an expander for buttons, an interrupt must be provided, polling mode is not acceptable. An expander w/o interruption can still be configured, but only output will be usable.
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+Each expander can support up to 32 GPIO. To use an expander for buttons, an interrupt must be provided, polling mode is not acceptable. An expander w/o interruption can still be configured, but only output will be usable.
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-The parameter "gpio_exp_config" supports the following syntax:
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+The parameter "gpio_exp_config" is a semicolon (;) separated list with following syntax for each expander
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```
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model=<model>,addr=<addr>,[,port=system|dac][,base=<n>|100][,count=<n>|16][,intr=<gpio>]
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```
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@@ -267,6 +267,7 @@ model=<model>,addr=<addr>,[,port=system|dac][,base=<n>|100][,count=<n>|16][,intr
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- count: number of GPIO of expander (default 16 - might be obsolted if model if sufficient to decide)
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- intr: real GPIO to use as interrupt.
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+Each expander must be
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Note that PWM ("led_brightness" below) is not supported for expanded GPIOs, neither connecting them to a rotary encoder (for speed reason) or high/precise signals like CS, D/C and RST and Ready. Depending on the actual chipset, pullup or pulldown might be supported.
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### LED
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See §**set_GPIO** for how to set the green and red LEDs. In addition, their brightness can be controlled using the "led_brigthness" parameter. The syntax is
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philippe44