From d1521eda56a4768dbf481aa6cf9e75c5a5a7e7f1 Mon Sep 17 00:00:00 2001 From: Scott Worley Date: Sat, 7 Oct 2023 23:29:49 -0700 Subject: [PATCH 1/1] client: Respond to button press --- client/CMakeLists.txt | 1 + client/button.c | 30 ++++++++++++++++++++++++++++++ client/button.h | 8 ++++++++ client/config.c | 7 +++++++ client/config.h | 7 +++++++ client/tattlekey.c | 31 +++++++++++++++++++++++++++---- 6 files changed, 80 insertions(+), 4 deletions(-) create mode 100644 client/button.c create mode 100644 client/button.h diff --git a/client/CMakeLists.txt b/client/CMakeLists.txt index ae97200..7714c1e 100644 --- a/client/CMakeLists.txt +++ b/client/CMakeLists.txt @@ -9,6 +9,7 @@ pico_sdk_init() add_executable(tattlekey blink.c + button.c config.c net.c tattlekey.c diff --git a/client/button.c b/client/button.c new file mode 100644 index 0000000..4df8d66 --- /dev/null +++ b/client/button.c @@ -0,0 +1,30 @@ +#include "button.h" +#include "config.h" + +#include "hardware/gpio.h" + +#include "pico/stdlib.h" + +static callback_t button_callback = NULL; + +static void respond_to_gpio_interrupt(uint gpio, uint32_t event_mask) { + if (gpio == button_pin && event_mask & GPIO_IRQ_EDGE_FALL && + button_callback) { + button_callback(); + } +} + +void begin_listening_for_button_press(callback_t callback) { + button_callback = callback; + + gpio_set_pulls(button_pin, 1, 0); + + /* Allow some time for the pull-up to take effect. + * I'm not sure if this is necessary. + * https://datasheets.raspberrypi.com/pico/raspberry-pi-pico-c-sdk.pdf says + * the internal GPIO pull-up resistors are 50k. */ + sleep_ms(100); + + gpio_set_irq_enabled_with_callback(button_pin, GPIO_IRQ_EDGE_FALL, 1, + respond_to_gpio_interrupt); +} diff --git a/client/button.h b/client/button.h new file mode 100644 index 0000000..9f82e15 --- /dev/null +++ b/client/button.h @@ -0,0 +1,8 @@ +#ifndef BUTTON_H +#define BUTTON_H + +typedef void (*callback_t)(); + +void begin_listening_for_button_press(callback_t callback); + +#endif diff --git a/client/config.c b/client/config.c index d2be496..a8e5844 100644 --- a/client/config.c +++ b/client/config.c @@ -10,3 +10,10 @@ u16_t tattle_port = 29803; // 'tk' /* For distinguishing reports from multiple tattlekey devices. */ u16_t this_tattler_identity = 1; + +/* Which GPIO pin is the button connected to? + * The button should span this pin and ground, connecting this pin to ground + * when pressed. + * https://projects.raspberrypi.org/en/projects/introduction-to-the-pico/10 + * recommends pins 18, 22, or 28. */ +uint button_pin = 18; diff --git a/client/config.h b/client/config.h index 97e2f8c..95c5651 100644 --- a/client/config.h +++ b/client/config.h @@ -14,4 +14,11 @@ extern u16_t tattle_port; /* For distinguishing reports from multiple tattlekey devices. */ extern u16_t this_tattler_identity; +/* Which GPIO pin is the button connected to? + * The button should span this pin and ground, connecting this pin to ground + * when pressed. + * https://projects.raspberrypi.org/en/projects/introduction-to-the-pico/10 + * recommends pins 18, 22, or 28. */ +extern uint button_pin; + #endif diff --git a/client/tattlekey.c b/client/tattlekey.c index ec77107..30f92a4 100644 --- a/client/tattlekey.c +++ b/client/tattlekey.c @@ -2,9 +2,34 @@ #include "pico/stdlib.h" #include "blink.h" +#include "button.h" #include "config.h" #include "net.h" +static u16_t seq = 0; + +static void button_pressed() { + /* TODO: This is interrupt context. We need to get out of interrupt context + * quickly; we should not be doing significant work here, & definitely + * shouldn't be sleeping here. We signal errors with blinking the LED, which + * involves sleeping, so this all has to move. */ + send_report(seq++, 0); + signal(4, 200); +} + +static void wait_forever() { + /* pico-examples/gpio/hello_gpio_irq/hello_gpio_irq.c implements wait-forever + * as "while (1);", but + * https://www.raspberrypi.com/documentation/pico-sdk/high_level.html#gaf469c6d691230e9d1008 + * says sleeping uses less power, so we sleep. */ + while (1) { + /* https://www.raspberrypi.com/documentation/pico-sdk/hardware.html#rpip7ce2cdc1662dce59296b + * says the maximum sleep is 2^32 - 1 microseconds (~71.58 minutes), so we + * sleep in chunks. */ + sleep_ms(1 << 31); /* 35.79 minutes */ + } +} + int main() { stdio_init_all(); if (cyw43_arch_init_with_country(CYW43_COUNTRY_USA)) @@ -16,9 +41,7 @@ int main() { CYW43_AUTH_WPA2_AES_PSK, 10000)) signal_error_by_blinking(); signal(3, 200); + begin_listening_for_button_press(button_pressed); - for (int i = 0;; i++) { - send_report(i, 0); - signal(4, 200); - } + wait_forever(); } -- 2.44.1