Initial Release

picoboard/CMakeLists.txt

@@ -0,0 +1,4 @@
+if (NOT PICO_NO_HARDWARE)
+    add_subdirectory(blinky)
+    add_subdirectory(button)
+endif ()

picoboard/blinky/CMakeLists.txt

@@ -0,0 +1,12 @@
+add_executable(picoboard_blinky
+        blinky.c
+        )
+
+# Pull in our pico_stdlib which pulls in commonly used features
+target_link_libraries(picoboard_blinky pico_stdlib)
+
+# create map/bin/hex file etc.
+pico_add_extra_outputs(picoboard_blinky)
+
+# add url via pico_set_program_url
+example_auto_set_url(picoboard_blinky)

picoboard/blinky/blinky.c

@@ -0,0 +1,75 @@
+/**
+ * Copyright (c) 2020 Raspberry Pi (Trading) Ltd.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <stdio.h>
+#include "pico/stdlib.h"
+#include "hardware/gpio.h"
+
+const uint LED_PIN = 25;
+const uint DOT_PERIOD_MS = 100;
+
+const char *morse_letters[] = {
+        ".-",    // A
+        "-...",  // B
+        "-.-.",  // C
+        "-..",   // D
+        ".",     // E
+        "..-.",  // F
+        "--.",   // G
+        "....",  // H
+        "..",    // I
+        ".---",  // J
+        "-.-",   // K
+        ".-..",  // L
+        "--",    // M
+        "-.",    // N
+        "---",   // O
+        ".--.",  // P
+        "--.-",  // Q
+        ".-.",   // R
+        "...",   // S
+        "-",     // T
+        "..-",   // U
+        "...-",  // V
+        ".--",   // W
+        "-..-",  // X
+        "-.--",  // Y
+        "--.."   // Z
+};
+
+void put_morse_letter(const char *pattern) {
+    for (; *pattern; ++pattern) {
+        gpio_put(LED_PIN, 1);
+        if (*pattern == '.')
+            sleep_ms(DOT_PERIOD_MS);
+        else
+            sleep_ms(DOT_PERIOD_MS * 3);
+        gpio_put(LED_PIN, 0);
+        sleep_ms(DOT_PERIOD_MS * 1);
+    }
+    sleep_ms(DOT_PERIOD_MS * 2);
+}
+
+void put_morse_str(const char *str) {
+    for (; *str; ++str) {
+        if (*str >= 'A' && *str < 'Z') {
+            put_morse_letter(morse_letters[*str - 'A']);
+        } else if (*str >= 'a' && *str < 'z') {
+            put_morse_letter(morse_letters[*str - 'a']);
+        } else if (*str == ' ') {
+            sleep_ms(DOT_PERIOD_MS * 4);
+        }
+    }
+}
+
+int main() {
+    gpio_init(LED_PIN);
+    gpio_set_dir(LED_PIN, GPIO_OUT);
+    while (true) {
+        put_morse_str("Hello world");
+        sleep_ms(1000);
+    }
+}

picoboard/button/CMakeLists.txt

@@ -0,0 +1,12 @@
+add_executable(picoboard_button
+        button.c
+        )
+
+# Pull in our pico_stdlib which pulls in commonly used features
+target_link_libraries(picoboard_button pico_stdlib)
+
+# create map/bin/hex file etc.
+pico_add_extra_outputs(picoboard_button)
+
+# add url via pico_set_program_url
+example_auto_set_url(picoboard_button)

picoboard/button/button.c

@@ -0,0 +1,62 @@
+/**
+ * Copyright (c) 2020 Raspberry Pi (Trading) Ltd.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <stdio.h>
+#include "pico/stdlib.h"
+#include "hardware/gpio.h"
+#include "hardware/sync.h"
+#include "hardware/structs/ioqspi.h"
+#include "hardware/structs/sio.h"
+
+// This example blinks the Picoboard LED when the BOOTSEL button is pressed.
+//
+// Picoboard has a button attached to the flash CS pin, which the bootrom
+// checks, and jumps straight to the USB bootcode if the button is pressed
+// (pulling flash CS low). We can check this pin in by jumping to some code in
+// SRAM (so that the XIP interface is not required), floating the flash CS
+// pin, and observing whether it is pulled low.
+//
+// This doesn't work if others are trying to access flash at the same time,
+// e.g. XIP streamer, or the other core.
+
+bool __no_inline_not_in_flash_func(get_bootsel_button)() {
+    const uint CS_PIN_INDEX = 1;
+
+    // Must disable interrupts, as interrupt handlers may be in flash, and we
+    // are about to temporarily disable flash access!
+    uint32_t flags = save_and_disable_interrupts();
+
+    // Set chip select to Hi-Z
+    hw_write_masked(&ioqspi_hw->io[CS_PIN_INDEX].ctrl,
+                    GPIO_OVERRIDE_LOW << IO_QSPI_GPIO_QSPI_SS_CTRL_OEOVER_LSB,
+                    IO_QSPI_GPIO_QSPI_SS_CTRL_OEOVER_BITS);
+
+    // Note we can't call into any sleep functions in flash right now
+    for (volatile int i = 0; i < 1000; ++i);
+
+    // The HI GPIO registers in SIO can observe and control the 6 QSPI pins.
+    // Note the button pulls the pin *low* when pressed.
+    bool button_state = !(sio_hw->gpio_hi_in & (1u << CS_PIN_INDEX));
+
+    // Need to restore the state of chip select, else we are going to have a
+    // bad time when we return to code in flash!
+    hw_write_masked(&ioqspi_hw->io[CS_PIN_INDEX].ctrl,
+                    GPIO_OVERRIDE_NORMAL << IO_QSPI_GPIO_QSPI_SS_CTRL_OEOVER_LSB,
+                    IO_QSPI_GPIO_QSPI_SS_CTRL_OEOVER_BITS);
+
+    restore_interrupts(flags);
+
+    return button_state;
+}
+
+int main() {
+    gpio_init(PICO_DEFAULT_LED_PIN);
+    gpio_set_dir(PICO_DEFAULT_LED_PIN, GPIO_OUT);
+    while (true) {
+        gpio_put(PICO_DEFAULT_LED_PIN, get_bootsel_button());
+        sleep_ms(10);
+    }
+}