--- /dev/null
+Simple pwm using serial input for duty-cycle control
+
+Copyright 2016 Nathael Pajani <nathael.pajani@ed3l.fr>
+
+
+/* ****************************************************************************
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ *
+ *************************************************************************** */
+
+This example shows the support of PWM for simple led brightness or fan speed control.
+PWM duty cycle is set by reading characters from the serial line.
+
+The PWM signal is output on port 0 pin 19 (LPC_TIMER_32B0_M1_PIO_0_19), using
+32 bits timer 0, match channel 1.
+
+The PWM period is fixed to 1kHz.
+
+
--- /dev/null
+/****************************************************************************
+ * simple_pwm/main.c
+ *
+ * Simple PWM example
+ *
+ * Copyright 2016 Nathael Pajani <nathael.pajani@ed3l.fr>
+ *
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ *
+ *************************************************************************** */
+
+
+#include "core/system.h"
+#include "core/systick.h"
+#include "core/pio.h"
+#include "lib/stdio.h"
+#include "drivers/serial.h"
+#include "drivers/gpio.h"
+#include "extdrv/status_led.h"
+#include "drivers/timers.h"
+
+
+#define MODULE_VERSION 0x04
+#define MODULE_NAME "GPIO Demo Module"
+
+
+#define SELECTED_FREQ FREQ_SEL_48MHz
+
+#define LPC_TIMER_PIN_CONFIG (LPC_IO_MODE_PULL_UP | LPC_IO_DIGITAL | LPC_IO_DRIVE_HIGHCURENT)
+
+/***************************************************************************** */
+/* Pins configuration */
+/* pins blocks are passed to set_pins() for pins configuration.
+ * Unused pin blocks can be removed safely with the corresponding set_pins() call
+ * All pins blocks may be safelly merged in a single block for single set_pins() call..
+ */
+const struct pio_config common_pins[] = {
+ /* UART 0 */
+ { LPC_UART0_RX_PIO_0_1, LPC_IO_DIGITAL },
+ { LPC_UART0_TX_PIO_0_2, LPC_IO_DIGITAL },
+ /* TIMER_32B1 */
+ { LPC_TIMER_32B1_M0_PIO_0_23, LPC_TIMER_PIN_CONFIG },
+ ARRAY_LAST_PIO,
+};
+
+
+const struct pio status_led_green = LPC_GPIO_0_28;
+const struct pio status_led_red = LPC_GPIO_0_29;
+
+/***************************************************************************** */
+static uint8_t timer = 0;
+static uint8_t channel = 0;
+static uint32_t pwm_one_step = 0;
+int pwm_config(uint8_t timer_num, uint8_t pwm_chan, uint8_t uart_num)
+{
+ uint32_t pwm_period = 0;
+ struct lpc_timer_pwm_config timer_conf = {
+ .nb_channels = 1,
+ .period_chan = 3,
+ };
+
+ timer = timer_num;
+ channel = pwm_chan;
+ timer_conf.outputs[0] = pwm_chan;
+
+ /* compute the period for the PWM signal */
+ /* We want 1ms (1kHz), timer counts at main clock frequency */
+ pwm_period = get_main_clock() / 10000;
+ pwm_one_step = (pwm_period / 100);
+ timer_conf.match_values[0] = 0;
+ timer_conf.period = pwm_period;
+
+ timer_on(timer, 0, NULL);
+ timer_pwm_config(timer, &timer_conf);
+ timer_start(timer);
+
+ uprintf(uart_num, "PWM configured (T%d : C%d), Period : %d, step : %d\n",
+ timer, channel, pwm_period, pwm_one_step);
+
+ return 0;
+}
+
+int set_duty_cycle(int c, int uart_num)
+{
+ uint16_t val = 0;
+
+ val = (c - '0') * 10;
+ if (val > 100) {
+ val = 100;
+ }
+ /* When using a mosfet to drive the load, the signal must be inverted to compensate */
+ val = 100 - val;
+
+ timer_set_match(timer, channel, (val * pwm_one_step));
+ uprintf(uart_num, "Channel %d duty cycle: %d%% (%d)\n", channel, (100 - val), val * pwm_one_step);
+ return val;
+}
+
+
+volatile int set_duty = -1;
+void change_pos(uint8_t c)
+{
+ set_duty = c;
+}
+
+/***************************************************************************** */
+void system_init()
+{
+ /* Stop the watchdog */
+ startup_watchdog_disable(); /* Do it right now, before it gets a chance to break in */
+ system_set_default_power_state();
+ clock_config(SELECTED_FREQ);
+ set_pins(common_pins);
+ gpio_on();
+ status_led_config(&status_led_green, &status_led_red);
+ /* System tick timer MUST be configured and running in order to use the sleeping
+ * functions */
+ systick_timer_on(1); /* 1ms */
+ systick_start();
+}
+
+/* Define our fault handler. This one is not mandatory, the dummy fault handler
+ * will be used when it's not overridden here.
+ * Note : The default one does a simple infinite loop. If the watchdog is deactivated
+ * the system will hang.
+ */
+void fault_info(const char* name, uint32_t len)
+{
+ uprintf(UART0, name);
+ while (1);
+}
+
+
+
+/***************************************************************************** */
+int main(void)
+{
+ system_init();
+ uart_on(UART0, 115200, change_pos);
+
+ pwm_config(LPC_TIMER_32B1, 0, UART0);
+
+ while (1) {
+ chenillard(500);
+ if (set_duty != -1) {
+ set_duty_cycle(set_duty, UART0);
+ set_duty = -1;
+ }
+ }
+ return 0;
+}
+
+
+
