- CC1101 Sub 1GHz RF Transceiver
- Status led
- Epaper display
+ - WS2812 chainable leds
- Other
- 8x8 font for use with Epaper display
--- /dev/null
+/****************************************************************************
+ * extdrv/ws2812.c
+ *
+ *
+ * Copyright 2013 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 2 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/>.
+ *
+ *************************************************************************** */
+
+/*
+ * Support for the WS2812 Chainable RGB Leds
+ *
+ * WS2812 protocol can be found here : https://www.adafruit.com/datasheets/WS2812.pdf
+ *
+ */
+
+#include <stdint.h>
+#include "core/lpc_regs_12xx.h"
+#include "core/lpc_core_cm0.h"
+#include "core/system.h"
+#include "core/pio.h"
+#include "drivers/gpio.h"
+#include "lib/string.h"
+#include "extdrv/ws2812.h"
+
+
+static struct pio ws2812_gpio = LPC_GPIO_0_0;
+
+/* Configure Selected GPIO as output. */
+void ws2812_config(const struct pio* gpio)
+{
+ config_pio(gpio, (LPC_IO_MODE_PULL_UP | LPC_IO_DIGITAL));
+ pio_copy(&ws2812_gpio, gpio);
+ gpio_dir_out(ws2812_gpio);
+}
+
+static uint8_t led_data[NB_LEDS * 3];
+static uint16_t max_led = 0;
+static uint32_t nb_bytes = 0;
+
+
+static void ws2812_bit_sender(void)
+{
+ struct lpc_gpio* gpio_port = LPC_GPIO_REGS(ws2812_gpio.port);
+ uint32_t gpio_bit = (1 << ws2812_gpio.pin);
+ uint32_t byte_idx = 0;
+ uint8_t bit_idx = 7;
+ uint8_t bit = 0;
+
+ lpc_disable_irq();
+
+ /* Send data */
+ while (byte_idx < nb_bytes) {
+ bit = (led_data[byte_idx] & (0x01 << bit_idx));
+
+ if (bit == 0) {
+ /* "high" time : 350ns */
+ gpio_port->set = gpio_bit;
+ nop();
+ nop();
+ nop();
+ nop();
+ nop();
+ nop();
+ nop();
+ nop();
+ /* "low" time : 800ns */
+ gpio_port->clear = gpio_bit;
+ nop();
+ nop();
+ nop();
+ nop();
+ nop();
+ nop();
+ nop();
+ nop();
+ } else {
+ /* "high" time : 700ns */
+ gpio_port->set = gpio_bit;
+ nop();
+ nop();
+ nop();
+ nop();
+ nop();
+ nop();
+ nop();
+ nop();
+ nop();
+ nop();
+ nop();
+ nop();
+ nop();
+ nop();
+ nop();
+ nop();
+ /* "high" time : 600ns */
+ gpio_port->clear = gpio_bit;
+ nop();
+ nop();
+ }
+
+ /* Move to the next bit */
+ if (bit_idx == 0) {
+ bit_idx = 7;
+ byte_idx++;
+ } else {
+ bit_idx--;
+ }
+ }
+
+ lpc_enable_irq();
+}
+
+/* Send led data from internal buffer (set leds to the selected color).
+ * If nb_leds is 0 then all led data set using ws2812_set_pixel() since the last call
+ * to ws2812_clear_buffer(), ws2812_clear() or ws2812_stop() will be sent.
+ * Call to this function will disable interrupts due to timming restrictions during
+ * the call to ws2812_bit_sender().
+ */
+int ws2812_send_frame(uint16_t nb_leds)
+{
+ if (nb_leds > NB_LEDS) {
+ return -1;
+ }
+ if (nb_leds == 0) {
+ nb_leds = max_led;
+ }
+ nb_bytes = (nb_leds + 1) * 3;
+ ws2812_bit_sender();
+ /* Reset delay */
+ usleep(60);
+ return 0;
+}
+
+/* Set a pixel (led) color in the data buffer */
+int ws2812_set_pixel(uint16_t pixel_num, uint8_t red, uint8_t green, uint8_t blue)
+{
+ if (pixel_num >= NB_LEDS) {
+ return -1;
+ }
+ led_data[ ((pixel_num * 3) + 0) ] = green;
+ led_data[ ((pixel_num * 3) + 1) ] = red;
+ led_data[ ((pixel_num * 3) + 2) ] = blue;
+ if (max_led < pixel_num) {
+ max_led = pixel_num;
+ }
+ return 0;
+}
+
+/* Clear the internal data buffer. */
+void ws2812_clear_buffer(void)
+{
+ memset(led_data, 0, (NB_LEDS * 3));
+ max_led = 0;
+}
+
+/* Clear the internal data buffer and send it to the Leds, turning them all off */
+void ws2812_clear(void)
+{
+ /* Start at first led and send all leds off */
+ ws2812_clear_buffer();
+ ws2812_send_frame(NB_LEDS);
+ max_led = 0;
+}
+
+void ws2812_stop(void) __attribute__ ((alias ("ws2812_clear")));
+
--- /dev/null
+/****************************************************************************
+ * extdrv/ws2812.h
+ *
+ *
+ * Copyright 2013 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 2 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/>.
+ *
+ *************************************************************************** */
+
+/*
+ * Support for the WS2812 Chainable RGB Leds
+ *
+ * WS2812 protocol can be found here : https://www.adafruit.com/datasheets/WS2812.pdf
+ *
+ */
+
+/*
+ * Preliminary notice :
+ * This driver will only function with a clock frequency of 48MHz (or close to) due to
+ * the use of nop() to get the right timmings.
+ *
+ * Internal data buffer :
+ * This driver uses an internal buffer for NB_LEDS leds or "pixels". The buffer
+ * size is (3 * NB_LEDS) bytes.
+ * The buffer is set pixel per pixel using the ws2812_set_pixel() function.
+ * The buffer is then sent to the led strip using ws2812_send_frame().
+ *
+ * Driving several led strips :
+ * It is possible to drive several led strips using this driver by calling the config
+ * function ws2812_config() between each ws2812_send_frame() call, and setting the led
+ * data again using the ws2812_set_pixel() function for each new led.
+ * This solution is not the most adapted for several led strips, and the driver should be
+ * modified to use an external buffer which address is either passed to each function or
+ * set using a modified version of the ws2812_config() function.
+ * In this case, the timmings should be checked and updated as access to the data may
+ * require more instructions.
+ *
+ * Note : ws2812_send_frame() will call lpc_disable_irq() to disable all interrupts
+ * when entering the timming critical section.
+ * Use of timers and interrupts have been tried but timmings are too short even
+ * whith the micro-controller running at 48MHz and direct access to the timer and
+ * GPIO registers.
+ * Instead the function uses a few nop() to get the right timmings.
+ *
+ */
+
+#include <stdint.h>
+#include "core/pio.h"
+
+
+/* Size of the internal buffer.
+ * Change the value to the number of leds of your led strip.
+ */
+#define NB_LEDS 60
+
+
+/* Configure the pin for the led data signal. */
+void ws2812_config(const struct pio* gpio);
+
+/* Send led data from internal buffer using the configured GPIO pin. (Set leds to the
+ * selected color).
+ * If no pin have been configured, GPIO_0_0 will be used.
+ * If nb_leds is 0 then all led data set using ws2812_set_pixel() since the last call
+ * to ws2812_clear_buffer(), ws2812_clear() or ws2812_stop() will be sent.
+ * Call to this function will disable interrupts due to timming restrictions.
+ * Return -1 on error (nb_leds above NB_LEDS), or 0 on success.
+ */
+int ws2812_send_frame(uint16_t nb_leds);
+
+/* Set a pixel (led) color in the data buffer (frame)
+ * The pixel number 'pixel_num' is the led offset in the led strip.
+ * 'red', 'green' and 'blue' are the color values of the pixel. A value of 0 is off,
+ * while a value of 0xFF (255) is full brightness.
+ * Return -1 on error (pixel_num above NB_LEDS), or 0 on success.
+ */
+int ws2812_set_pixel(uint16_t pixel_num, uint8_t red, uint8_t green, uint8_t blue);
+
+/* Clear the internal data buffer. */
+void ws2812_clear_buffer(void);
+
+/* Clear the internal data buffer and send it to the Leds, turning them all off */
+void ws2812_clear(void);
+/* Alias for ws2812_clear */
+void ws2812_stop(void);
+
