Add blink_btn.

README.md

@@ -6,6 +6,10 @@ They aren't too specific for the bat boards, except the usual pinout considerati
 
 ## Short summary for the examples
 
+### blink_btn
+
+The onboard LED blinks, holding the button slows the frequency somewhat. The clocks are set up to 48MHz on F072, 32MHz on L052 (max).
+
 ### usb_cdcacm
 
 The board presents itself as a serial port (CDC). It echoes back what it receives; toggling the LED after each received packet. Pressing the `PA1` button will print `hello, world` over this port.

blink_btn/Makefile.f0

@@ -0,0 +1,26 @@
+##
+## This file is part of the libopencm3 project.
+##
+## Copyright (C) 2009 Uwe Hermann <uwe@hermann-uwe.de>
+##
+## This library is free software: you can redistribute it and/or modify
+## it under the terms of the GNU Lesser General Public License as published by
+## the Free Software Foundation, either version 3 of the License, or
+## (at your option) any later version.
+##
+## This library is distributed in the hope that it will be useful,
+## but WITHOUT ANY WARRANTY; without even the implied warranty of
+## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+## GNU Lesser General Public License for more details.
+##
+## You should have received a copy of the GNU Lesser General Public License
+## along with this library.  If not, see <http://www.gnu.org/licenses/>.
+##
+
+BINARY = button
+
+OPENCM3_DIR=../libopencm3
+LDSCRIPT = $(OPENCM3_DIR)/lib/stm32/f0/stm32f07xzb.ld
+
+include ../common.f0.mk
+

blink_btn/Makefile.l0

@@ -0,0 +1,26 @@
+##
+## This file is part of the libopencm3 project.
+##
+## Copyright (C) 2009 Uwe Hermann <uwe@hermann-uwe.de>
+##
+## This library is free software: you can redistribute it and/or modify
+## it under the terms of the GNU Lesser General Public License as published by
+## the Free Software Foundation, either version 3 of the License, or
+## (at your option) any later version.
+##
+## This library is distributed in the hope that it will be useful,
+## but WITHOUT ANY WARRANTY; without even the implied warranty of
+## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+## GNU Lesser General Public License for more details.
+##
+## You should have received a copy of the GNU Lesser General Public License
+## along with this library.  If not, see <http://www.gnu.org/licenses/>.
+##
+
+BINARY = button
+
+OPENCM3_DIR=../libopencm3
+LDSCRIPT = $(OPENCM3_DIR)/lib/stm32/l0/stm32l0xx8.ld
+
+include ../common.l0.mk
+

blink_btn/Makefile.l0btld

@@ -0,0 +1,27 @@
+##
+## This file is part of the libopencm3 project.
+##
+## Copyright (C) 2009 Uwe Hermann <uwe@hermann-uwe.de>
+##
+## This library is free software: you can redistribute it and/or modify
+## it under the terms of the GNU Lesser General Public License as published by
+## the Free Software Foundation, either version 3 of the License, or
+## (at your option) any later version.
+##
+## This library is distributed in the hope that it will be useful,
+## but WITHOUT ANY WARRANTY; without even the implied warranty of
+## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+## GNU Lesser General Public License for more details.
+##
+## You should have received a copy of the GNU Lesser General Public License
+## along with this library.  If not, see <http://www.gnu.org/licenses/>.
+##
+
+BINARY = button
+
+OPENCM3_DIR=../libopencm3
+LDSCRIPT = ../l052-bldr.ld
+DEFS += -DBOOTLOADER8K
+
+include ../common.l0.mk
+

blink_btn/button.c

@@ -0,0 +1,126 @@
+/*
+ * This file is part of the libopencm3 project.
+ *
+ * Copyright (C) 2009 Uwe Hermann <uwe@hermann-uwe.de>,
+ * Copyright (C) 2010 Piotr Esden-Tempski <piotr@esden.net>
+ * Copyright (C) 2011 Stephen Caudle <scaudle@doceme.com>
+ *
+ * This library is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this library.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <libopencm3/stm32/rcc.h>
+#include <libopencm3/stm32/flash.h>
+#include <libopencm3/stm32/gpio.h>
+
+#define LED_GPIO GPIOA
+#define LED_PIN GPIO15
+#define LED_RCC_GPIO RCC_GPIOA
+#define BUTTON_GPIO GPIOA
+#define BUTTON_PIN GPIO1
+#define BUTTON_RCC_GPIO RCC_GPIOA
+
+/* Set the clock to max speed. */
+static void clock_setup(void)
+{
+#if defined(STM32F0)
+	rcc_clock_setup_in_hsi_out_48mhz();
+#elif defined(STM32L0)
+	/* After a reset, the system uses MSI@2.1MHz. */
+	/* end result: 32MHz PLLVCO from HSI16,
+	 *	 no system/periph clock divide.
+	 */
+
+	/* increase the latency to 1 wait state (we'll be speeding up) */
+	flash_set_ws(1);
+
+	/* turn on HSI16 */
+	rcc_osc_on(RCC_HSI16);
+	rcc_wait_for_osc_ready(RCC_HSI16);
+
+	/* run AHB, APB1, APB2 at full speed */
+	rcc_set_hpre(RCC_CFGR_HPRE_NODIV);
+	rcc_set_ppre1(RCC_CFGR_PPRE1_NODIV);
+	rcc_set_ppre2(RCC_CFGR_PPRE2_NODIV);
+
+	/* turn off PLL and wait for it to fully stop */
+	rcc_osc_off(RCC_PLL);
+	while (RCC_CR & RCC_CR_PLLRDY);
+
+	/* set PLL source to HSI16 */
+	RCC_CFGR &= ~(1<<16); // RCC_CFGR_PLLSRC
+
+	/* set up PLL */
+	rcc_set_pll_multiplier(RCC_CFGR_PLLMUL_MUL4);
+	rcc_set_pll_divider(RCC_CFGR_PLLDIV_DIV2);
+
+	/* turn on and switch to PLL */
+	rcc_osc_on(RCC_PLL);
+	rcc_wait_for_osc_ready(RCC_PLL);
+	rcc_set_sysclk_source(RCC_PLL);
+
+	rcc_ahb_frequency = 32000000;
+	rcc_apb1_frequency = 32000000;
+	rcc_apb2_frequency = 32000000;
+#else
+	#error "Implement a clock setup."
+#endif
+}
+
+static void gpio_setup(void)
+{
+	/* Enable clocks. */
+	rcc_periph_clock_enable(LED_RCC_GPIO);
+	rcc_periph_clock_enable(BUTTON_RCC_GPIO);
+
+	/* Set the LED pin to 'output push-pull'. */
+	gpio_mode_setup(LED_GPIO, GPIO_MODE_OUTPUT,
+			GPIO_PUPD_NONE, LED_PIN);
+
+	/* Set the button pin to 'input' (external pull-down). */
+	gpio_mode_setup(BUTTON_GPIO, GPIO_MODE_INPUT, GPIO_PUPD_NONE, BUTTON_PIN);
+}
+
+#define SCB_VTOR MMIO32(0xE000ED08)
+
+int main(void)
+{
+#if defined(BOOTLOADER8K)
+	SCB_VTOR = (uint32_t) 0x08002000;
+#endif
+
+	int i;
+
+	clock_setup();
+	gpio_setup();
+
+	/* Blink the LED on the board. */
+	while (1) {
+		gpio_toggle(LED_GPIO, LED_PIN);
+
+		/* Upon button press, blink more slowly. */
+		if (gpio_get(BUTTON_GPIO, BUTTON_PIN)) {
+			for (i = 0; i < 2000000; i++) {	/* Wait a bit. */
+				__asm__("nop");
+			}
+		}
+
+		for (i = 0; i < 2000000; i++) {		/* Wait a bit. */
+			__asm__("nop");
+		}
+	}
+
+	return 0;
+}
+
+// vim: tabstop=4:shiftwidth=4:noexpandtab