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authorPiotr Esden-Tempski2012-11-11 21:02:15 -0800
committerPiotr Esden-Tempski2012-11-11 21:02:15 -0800
commit4691568ca476177dc338e8c62872ceca6b4b4999 (patch)
tree202230f298d4cd1385373dcb6136626eb8849c65 /examples
parent7006d3c45770fc46647968985bb3f959f50d1de3 (diff)
[examples] Added CAN example for obldc strip.
Diffstat (limited to 'examples')
-rw-r--r--examples/stm32/f1/obldc-strip/can/Makefile25
-rw-r--r--examples/stm32/f1/obldc-strip/can/README4
-rw-r--r--examples/stm32/f1/obldc-strip/can/can.c202
3 files changed, 231 insertions, 0 deletions
diff --git a/examples/stm32/f1/obldc-strip/can/Makefile b/examples/stm32/f1/obldc-strip/can/Makefile
new file mode 100644
index 0000000..ae14841
--- /dev/null
+++ b/examples/stm32/f1/obldc-strip/can/Makefile
@@ -0,0 +1,25 @@
+##
+## 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 = can
+
+LDSCRIPT = ../obldc-strip.ld
+
+include ../../Makefile.include
+
diff --git a/examples/stm32/f1/obldc-strip/can/README b/examples/stm32/f1/obldc-strip/can/README
new file mode 100644
index 0000000..3a14e3b
--- /dev/null
+++ b/examples/stm32/f1/obldc-strip/can/README
@@ -0,0 +1,4 @@
+This test sets up the CAN interface on Lisa/M and transmits 8 bites every
+100ms. The first byte is being incremented in each cycle. The demo also
+receives messages and is displaing the first 4 bits of the first byte on the
+board LEDs.
diff --git a/examples/stm32/f1/obldc-strip/can/can.c b/examples/stm32/f1/obldc-strip/can/can.c
new file mode 100644
index 0000000..82473e1
--- /dev/null
+++ b/examples/stm32/f1/obldc-strip/can/can.c
@@ -0,0 +1,202 @@
+/*
+ * This file is part of the libopencm3 project.
+ *
+ * Copyright (C) 2012 Piotr Esden-Tempski <piotr@esden.net>
+ *
+ * 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/f1/rcc.h>
+#include <libopencm3/stm32/f1/flash.h>
+#include <libopencm3/stm32/f1/gpio.h>
+#include <libopencm3/cm3/nvic.h>
+#include <libopencm3/cm3/systick.h>
+#include <libopencm3/stm32/can.h>
+
+struct can_tx_msg {
+ u32 std_id;
+ u32 ext_id;
+ u8 ide;
+ u8 rtr;
+ u8 dlc;
+ u8 data[8];
+};
+
+struct can_rx_msg {
+ u32 std_id;
+ u32 ext_id;
+ u8 ide;
+ u8 rtr;
+ u8 dlc;
+ u8 data[8];
+ u8 fmi;
+};
+
+struct can_tx_msg can_tx_msg;
+struct can_rx_msg can_rx_msg;
+
+void gpio_setup(void)
+{
+ /* Enable Alternate Function clock. */
+ rcc_peripheral_enable_clock(&RCC_APB2ENR, RCC_APB2ENR_AFIOEN);
+
+ /* Enable GPIOB clock. */
+ rcc_peripheral_enable_clock(&RCC_APB2ENR, RCC_APB2ENR_IOPBEN);
+
+ /* Preconfigure LEDs. */
+ gpio_set(GPIOB, GPIO4); /* LED green off */
+ gpio_set(GPIOB, GPIO5); /* LED red off */
+
+ /* Configure LED GPIOs. */
+ gpio_set_mode(GPIOB, GPIO_MODE_OUTPUT_50_MHZ,
+ GPIO_CNF_OUTPUT_PUSHPULL, GPIO4);
+ gpio_set_mode(GPIOB, GPIO_MODE_OUTPUT_50_MHZ,
+ GPIO_CNF_OUTPUT_PUSHPULL, GPIO5);
+
+ /* Configure PB4 as GPIO. */
+ AFIO_MAPR |= AFIO_MAPR_SWJ_CFG_FULL_SWJ_NO_JNTRST;
+
+}
+
+void systick_setup(void)
+{
+ /* 64MHz / 8 => 8000000 counts per second */
+ systick_set_clocksource(STK_CTRL_CLKSOURCE_AHB_DIV8);
+
+ /* 8000000/8000 = 1000 overflows per second - every 1ms one interrupt */
+ systick_set_reload(8000);
+
+ systick_interrupt_enable();
+
+ /* Start counting. */
+ systick_counter_enable();
+}
+
+void can_setup(void)
+{
+ /* Enable peripheral clocks. */
+ rcc_peripheral_enable_clock(&RCC_APB2ENR, RCC_APB2ENR_AFIOEN);
+ rcc_peripheral_enable_clock(&RCC_APB2ENR, RCC_APB2ENR_IOPBEN);
+ rcc_peripheral_enable_clock(&RCC_APB1ENR, RCC_APB1ENR_CAN1EN);
+
+ AFIO_MAPR |= AFIO_MAPR_CAN1_REMAP_PORTB;
+
+ /* Configure CAN pin: RX (input pull-up). */
+ gpio_set_mode(GPIO_BANK_CAN1_PB_RX, GPIO_MODE_INPUT,
+ GPIO_CNF_INPUT_PULL_UPDOWN, GPIO_CAN1_PB_RX);
+ gpio_set(GPIO_BANK_CAN1_PB_RX, GPIO_CAN1_PB_RX);
+
+ /* Configure CAN pin: TX. */
+ gpio_set_mode(GPIO_BANK_CAN1_PB_TX, GPIO_MODE_OUTPUT_50_MHZ,
+ GPIO_CNF_OUTPUT_ALTFN_PUSHPULL, GPIO_CAN1_PB_TX);
+
+ /* NVIC setup. */
+ nvic_enable_irq(NVIC_USB_LP_CAN_RX0_IRQ);
+ nvic_set_priority(NVIC_USB_LP_CAN_RX0_IRQ, 1);
+
+ /* Reset CAN. */
+ can_reset(CAN1);
+
+ /* CAN cell init.
+ * Setting the bitrate to 1MBit. APB1 = 32MHz,
+ * prescaler = 2 -> 16MHz time quanta frequency.
+ * 1tq sync + 9tq bit segment1 (TS1) + 6tq bit segment2 (TS2) =
+ * 16time quanto per bit period, therefor 16MHz/16 = 1MHz
+ */
+ if (can_init(CAN1,
+ false, /* TTCM: Time triggered comm mode? */
+ true, /* ABOM: Automatic bus-off management? */
+ false, /* AWUM: Automatic wakeup mode? */
+ false, /* NART: No automatic retransmission? */
+ false, /* RFLM: Receive FIFO locked mode? */
+ false, /* TXFP: Transmit FIFO priority? */
+ CAN_BTR_SJW_1TQ,
+ CAN_BTR_TS1_9TQ,
+ CAN_BTR_TS2_6TQ,
+ 2)) /* BRP+1: Baud rate prescaler */
+ {
+ gpio_clear(GPIOB, GPIO4); /* LED green on */
+ gpio_set(GPIOB, GPIO5); /* LED red off */
+
+ /* Die because we failed to initialize. */
+ while (1)
+ __asm__("nop");
+ }
+
+ /* CAN filter 0 init. */
+ can_filter_id_mask_32bit_init(CAN1,
+ 0, /* Filter ID */
+ 0, /* CAN ID */
+ 0, /* CAN ID mask */
+ 0, /* FIFO assignment (here: FIFO0) */
+ true); /* Enable the filter. */
+
+ /* Enable CAN RX interrupt. */
+ can_enable_irq(CAN1, CAN_IER_FMPIE0);
+}
+
+void sys_tick_handler(void)
+{
+ static u8 data[8] = {0, 1, 2, 0, 0, 0, 0, 0};
+
+ /* We call this handler every 1ms so every 1ms = 0.001s
+ * resulting in 1000Hz message rate.
+ */
+
+ /* Transmit CAN frame. */
+ data[0]++;
+ if (can_transmit(CAN1,
+ 0, /* (EX/ST)ID: CAN ID */
+ false, /* IDE: CAN ID extended? */
+ false, /* RTR: Request transmit? */
+ 8, /* DLC: Data length */
+ data) == -1)
+ {
+ gpio_set(GPIOB, GPIO4); /* LED green off */
+ gpio_clear(GPIOB, GPIO5); /* LED red on */
+ }
+}
+
+void usb_lp_can_rx0_isr(void)
+{
+ u32 id, fmi;
+ bool ext, rtr;
+ u8 length, data[8];
+
+ can_receive(CAN1, 0, false, &id, &ext, &rtr, &fmi, &length, data);
+
+ if (data[0] & 0x40)
+ gpio_clear(GPIOB, GPIO4);
+ else
+ gpio_set(GPIOB, GPIO4);
+
+ if (data[0] & 0x80)
+ gpio_clear(GPIOB, GPIO5);
+ else
+ gpio_set(GPIOB, GPIO5);
+
+ can_fifo_release(CAN1, 0);
+}
+
+int main(void)
+{
+ rcc_clock_setup_in_hsi_out_64mhz();
+ gpio_setup();
+ can_setup();
+ systick_setup();
+
+ while (1); /* Halt. */
+
+ return 0;
+}