New pca9685 pwm output driver

boards/px4/raspberrypi/default.cmake

@@ -22,6 +22,7 @@ px4_add_board(
 		linux_sbus
 		#magnetometer # all available magnetometer drivers
 		magnetometer/hmc5883
+		pca9685_pwm_out
 		pwm_out_sim
 		rc_input
 		rpi_rc_in

src/drivers/pca9685_pwm_out/CMakeLists.txt

@@ -0,0 +1,44 @@
+############################################################################
+#
+#   Copyright (c) 2019 PX4 Development Team. All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions
+# are met:
+#
+# 1. Redistributions of source code must retain the above copyright
+#    notice, this list of conditions and the following disclaimer.
+# 2. Redistributions in binary form must reproduce the above copyright
+#    notice, this list of conditions and the following disclaimer in
+#    the documentation and/or other materials provided with the
+#    distribution.
+# 3. Neither the name PX4 nor the names of its contributors may be
+#    used to endorse or promote products derived from this software
+#    without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+# FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+# COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+# INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+# BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+# OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+# AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+# ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+# POSSIBILITY OF SUCH DAMAGE.
+#
+############################################################################
+px4_add_module(
+	MODULE drivers__pca9685
+	MAIN pca9685_pwm_out
+	COMPILE_FLAGS
+	SRCS
+		main.cpp
+		PCA9685.cpp
+	DEPENDS
+		mixer
+		mixer_module
+		output_limit
+	)

src/drivers/pca9685_pwm_out/PCA9685.cpp

@@ -0,0 +1,279 @@
+/****************************************************************************
+ *
+ *   Copyright (c) 2019 PX4 Development Team. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ * 3. Neither the name PX4 nor the names of its contributors may be
+ *    used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ ****************************************************************************/
+
+#include <px4_log.h>
+#include <cmath>
+#include "PCA9685.h"
+
+using namespace drv_pca9685_pwm;
+
+PCA9685::PCA9685(int bus, int addr):
+	I2C("PCA9685", PWM_OUTPUT0_DEVICE_PATH, bus, addr, 400000)
+{
+
+}
+
+int PCA9685::Start()
+{
+	int ret = init();
+	return ret;
+}
+
+int PCA9685::Stop()
+{
+	disableAllOutput();
+	return PX4_OK;
+}
+
+int PCA9685::updatePWM(const uint16_t *outputs, unsigned num_outputs)
+{
+	if (num_outputs > PCA9685_PWM_CHANNEL_COUNT) {
+		num_outputs = PCA9685_PWM_CHANNEL_COUNT;
+		PX4_WARN("PCA9685 can only drive up to 16 channels");
+	}
+
+	uint16_t out[PCA9685_PWM_CHANNEL_COUNT];
+	memcpy(out, outputs, sizeof(uint16_t) * num_outputs);
+
+	for (unsigned i = 0; i < num_outputs; ++i) {
+		out[i] = (uint16_t)roundl((out[i] * _Freq * PCA9685_PWM_RES / (float)1e6)); // convert us to 12 bit resolution
+	}
+
+	setPWM(num_outputs, out);
+
+	return 0;
+}
+
+int PCA9685::setFreq(int freq)
+{
+	uint16_t realResolution = floorl((double)PCA9685_CLOCK_FREQ / freq);
+
+	if (realResolution < PCA9685_PWM_RES) { // unable to provide enough resolution
+		PX4_DEBUG("frequency too high");
+		return -EINVAL;
+	}
+
+	uint16_t divider = (uint16_t)round((double)PCA9685_CLOCK_FREQ / freq / PCA9685_PWM_RES) - 1;
+
+	if (divider > 0x00FF) { // out of divider
+		PX4_DEBUG("frequency too low");
+		return -EINVAL;
+	}
+
+	float freq_err = ((float)PCA9685_CLOCK_FREQ / (float)(divider + (uint16_t)1)
+			  - (float)(freq * PCA9685_PWM_RES))
+			 / (float)(freq * PCA9685_PWM_RES); // actually asked for (freq * PCA9685_PWM_RES)
+
+	if (fabsf(freq_err) > 0.01f) { // TODO decide threshold
+		PX4_WARN("frequency error too large: %.4f", (double)freq_err);
+		// should we return an error?
+	}
+
+	_Freq = (float)PCA9685_CLOCK_FREQ / (float)(divider + (uint16_t)1) / PCA9685_PWM_RES; // use actual pwm freq instead.
+
+	setDivider(divider);
+
+	return PX4_OK;
+
+}
+
+int PCA9685::init()
+{
+	int ret = I2C::init();
+
+	if (ret != PX4_OK) {
+		PX4_DEBUG("I2C init failed.");
+		return ret;
+	}
+
+	uint8_t buf[2] = {};
+	buf[0] = PCA9685_REG_MODE1;
+	buf[1] = DEFAULT_MODE1_CFG;
+	ret = transfer(buf, 2, nullptr, 0);
+
+	if (OK != ret) {
+		PX4_DEBUG("i2c::transfer returned %d", ret);
+		return ret;
+	}
+
+	buf[0] = PCA9685_REG_MODE2;
+	buf[1] = DEFAULT_MODE2_CFG;
+	ret = transfer(buf, 2, nullptr, 0);
+
+	if (OK != ret) {
+		PX4_DEBUG("i2c::transfer returned %d", ret);
+		return ret;
+	}
+
+	disableAllOutput();
+
+	return PX4_OK;
+}
+
+int PCA9685::probe()
+{
+	return I2C::probe();
+}
+
+void PCA9685::setPWM(uint8_t channel, const uint16_t &value)
+{
+	if (value >= 4096) {
+		PX4_DEBUG("invalid pwm value");
+		return;
+	}
+
+	uint8_t buf[5] = {};
+	buf[0] = PCA9685_REG_LED0 + channel * PCA9685_REG_LED_INCREMENT;
+	buf[1] = 0x00;
+	buf[2] = 0x00;
+	buf[3] = (uint8_t)(value & (uint8_t)0xFF);
+	buf[4] = value != 0 ? ((uint8_t)(value >> (uint8_t)8)) : PCA9685_LED_ON_FULL_ON_OFF_MASK;
+
+	int ret = transfer(buf, 5, nullptr, 0);
+
+	if (OK != ret) {
+		PX4_DEBUG("i2c::transfer returned %d", ret);
+	}
+}
+
+void PCA9685::setPWM(uint8_t channel_count, const uint16_t *value)
+{
+	uint8_t buf[PCA9685_PWM_CHANNEL_COUNT * PCA9685_REG_LED_INCREMENT + 1] = {};
+	buf[0] = PCA9685_REG_LED0;
+
+	for (int i = 0; i < channel_count; ++i) {
+		if (value[i] >= 4096) {
+			PX4_DEBUG("invalid pwm value");
+			return;
+		}
+
+		buf[1 + i * PCA9685_REG_LED_INCREMENT] = 0x00;
+		buf[2 + i * PCA9685_REG_LED_INCREMENT] = 0x00;
+		buf[3 + i * PCA9685_REG_LED_INCREMENT] = (uint8_t)(value[i] & (uint8_t)0xFF);
+		buf[4 + i * PCA9685_REG_LED_INCREMENT] = value[i] != 0 ? ((uint8_t)(value[i] >> (uint8_t)8)) :
+				PCA9685_LED_ON_FULL_ON_OFF_MASK;
+	}
+
+	int ret = transfer(buf, channel_count * PCA9685_REG_LED_INCREMENT + 1, nullptr, 0);
+
+	if (OK != ret) {
+		PX4_DEBUG("i2c::transfer returned %d", ret);
+	}
+}
+
+void PCA9685::disableAllOutput()
+{
+	uint8_t buf[5] = {};
+	buf[0] = PCA9685_REG_ALLLED_ON_L;
+	buf[1] = 0x00;
+	buf[2] = 0x00;
+	buf[3] = (uint8_t)(0x00 & (uint8_t)0xFF);
+	buf[4] = PCA9685_LED_ON_FULL_ON_OFF_MASK;
+
+	int ret = transfer(buf, 5, nullptr, 0);
+
+	if (OK != ret) {
+		PX4_DEBUG("i2c::transfer returned %d", ret);
+	}
+}
+
+void PCA9685::setDivider(uint8_t value)
+{
+	disableAllOutput();
+	stopOscillator();
+	uint8_t buf[2] = {};
+	buf[0] = PCA9685_REG_PRE_SCALE;
+	buf[1] = value;
+	int ret = transfer(buf, 2, nullptr, 0);
+
+	if (OK != ret) {
+		PX4_DEBUG("i2c::transfer returned %d", ret);
+		return;
+	}
+
+	restartOscillator();
+}
+
+void PCA9685::stopOscillator()
+{
+	uint8_t buf[2] = {PCA9685_REG_MODE1};
+	int ret = transfer(buf, 1, buf, 1);
+
+	if (OK != ret) {
+		PX4_DEBUG("i2c::transfer returned %d", ret);
+		return;
+	}
+
+	buf[1] = buf[0];
+	buf[0] = PCA9685_REG_MODE1;
+	// clear restart bit
+	buf[1] |= PCA9685_MODE1_SLEEP_MASK;
+	ret = transfer(buf, 2, nullptr, 0);
+
+	if (OK != ret) {
+		PX4_DEBUG("i2c::transfer returned %d", ret);
+		return;
+	}
+}
+
+void PCA9685::restartOscillator()
+{
+	uint8_t buf[2] = {PCA9685_REG_MODE1};
+	int ret = transfer(buf, 1, buf + 1, 1);
+
+	if (OK != ret) {
+		PX4_DEBUG("i2c::transfer returned %d", ret);
+		return;
+	}
+
+	// clear restart and sleep bit
+	buf[1] &= PCA9685_MODE1_EXTCLK_MASK | PCA9685_MODE1_AI_MASK
+		  | PCA9685_MODE1_SUB1_MASK | PCA9685_MODE1_SUB2_MASK
+		  | PCA9685_MODE1_SUB3_MASK | PCA9685_MODE1_ALLCALL_MASK;
+	buf[0] = PCA9685_REG_MODE1;
+	ret = transfer(buf, 2, nullptr, 0);
+
+	if (OK != ret) {
+		PX4_DEBUG("i2c::transfer returned %d", ret);
+		return;
+	}
+
+	usleep(5000);
+	buf[1] |= PCA9685_MODE1_RESTART_MASK;
+	ret = transfer(buf, 2, nullptr, 0);
+
+	if (OK != ret) {
+		PX4_DEBUG("i2c::transfer returned %d", ret);
+		return;
+	}
+}

src/drivers/pca9685_pwm_out/PCA9685.h

@@ -0,0 +1,163 @@
+/****************************************************************************
+ *
+ *   Copyright (c) 2019 PX4 Development Team. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ * 3. Neither the name PX4 nor the names of its contributors may be
+ *    used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ ****************************************************************************/
+
+#pragma once
+#include <cstdint>
+#include <drivers/device/i2c.h>
+#include <drivers/drv_pwm_output.h>
+
+namespace drv_pca9685_pwm
+{
+
+#define PCA9685_REG_MODE1 0x00			// Mode  register  1
+#define PCA9685_REG_MODE2 0x01			// Mode  register  2
+#define PCA9685_REG_SUBADR1 0x02		// I2C-bus subaddress 1
+#define PCA9685_REG_SUBADR2 0x03		// I2C-bus subaddress 2
+#define PCA9685_REG_SUBADR3 0x04		// I2C-bus subaddress 3
+#define PCA9685_REG_ALLCALLADR 0x05     // LED All Call I2C-bus address
+#define PCA9685_REG_LED0 0x06			// LED0 start register
+#define PCA9685_REG_LED0_ON_L 0x06		// LED0 output and brightness control byte 0
+#define PCA9685_REG_LED0_ON_H 0x07		// LED0 output and brightness control byte 1
+#define PCA9685_REG_LED0_OFF_L 0x08		// LED0 output and brightness control byte 2
+#define PCA9685_REG_LED0_OFF_H 0x09		// LED0 output and brightness control byte 3
+#define PCA9685_REG_LED_INCREMENT 4 	// compute the other 15 channels
+#define PCA9685_REG_ALLLED_ON_L 0xFA    // load all the LEDn_ON registers, byte 0 (turn 0-7 channels on)
+#define PCA9685_REG_ALLLED_ON_H 0xFB	// load all the LEDn_ON registers, byte 1 (turn 8-15 channels on)
+#define PCA9685_REG_ALLLED_OFF_L 0xFC	// load all the LEDn_OFF registers, byte 0 (turn 0-7 channels off)
+#define PCA9685_REG_ALLLED_OFF_H 0xFD	// load all the LEDn_OFF registers, byte 1 (turn 8-15 channels off)
+#define PCA9685_REG_PRE_SCALE 0xFE		// prescaler for output frequency
+#define PCA9685_REG_TESTMODE 0xFF       // test mode register
+
+// Mode register 1
+#define PCA9685_MODE1_RESTART_MASK 0x80
+#define PCA9685_MODE1_EXTCLK_MASK 0x40
+#define PCA9685_MODE1_AI_MASK 0x20
+#define PCA9685_MODE1_SLEEP_MASK 0x10
+#define PCA9685_MODE1_SUB1_MASK 0x08
+#define PCA9685_MODE1_SUB2_MASK 0x04
+#define PCA9685_MODE1_SUB3_MASK 0x02
+#define PCA9685_MODE1_ALLCALL_MASK 0x01
+
+// Mode register 2
+#define PCA9685_MODE2_INVRT_MASK 0x10
+#define PCA9685_MODE2_OCH_MASK 0x08
+#define PCA9685_MODE2_OUTDRV_MASK 0x04
+#define PCA9685_MODE2_OUTNE_MASK 0x03
+
+// LED_ON, LED_OFF control registers
+#define PCA9685_LED0_ON_L_MASK 0xFF
+#define PCA9685_LED_ON_FULL_ON_OFF_MASK 0x10
+#define PCA9685_LED0_ON_H_MASK 0x0F
+
+// PRE_SCALE register
+#define PCA9685_PRE_SCALE_MASK 0xFF
+
+#define PCA9685_PWM_CHANNEL_COUNT 16
+#define PCA9685_PWM_RES 4096        //Resolution 4096=12bit
+#define PCA9685_CLOCK_INT 25000000.0 //25MHz internal clock
+#ifndef PCA9685_CLOCL_EXT
+#define PCA9685_CLOCK_FREQ PCA9685_CLOCK_INT   // use int clk
+#else
+#define PCA9685_CLOCK_FREQ PCA9685_CLOCK_EXT   // use ext clk
+#endif
+
+#define PWM_DEFAULT_FREQUENCY 50    // default pwm frequency
+
+//! Main class that exports features for PCA9685 chip
+class PCA9685 : public device::I2C
+{
+public:
+	PCA9685(int bus, int addr);
+
+	int Start();
+
+	int Stop();
+
+	/*
+	 * outputs formatted to us.
+	 */
+	int updatePWM(const uint16_t *outputs, unsigned num_outputs);
+
+	int setFreq(int freq);
+
+	~PCA9685() override = default;
+
+	int init() override;
+
+	inline float getFrequency() {return _Freq;}
+
+protected:
+	int probe() override;
+
+	static const uint8_t DEFAULT_MODE1_CFG = 0x20;
+	static const uint8_t DEFAULT_MODE2_CFG = 0x04;
+
+	float _Freq = PWM_DEFAULT_FREQUENCY;
+
+	/**
+	 * set PWM value for a channel[0,15].
+	 * value should be range of 0-4095
+	 */
+	void setPWM(uint8_t channel, const uint16_t &value);
+
+	/**
+	 * set all PWMs in a single I2C transmission.
+	 * value should be range of 0-4095
+	 */
+	void setPWM(uint8_t channel_count, const uint16_t *value);
+
+	/*
+	 * disable all of the output
+	 */
+	void disableAllOutput();
+
+	/*
+	 * set clock divider
+	 * this func has Super Cow Powers
+	 */
+	void setDivider(uint8_t value);
+
+	/*
+	 * turn off oscillator
+	 */
+	void stopOscillator();
+
+	/*
+	 * restart output
+	 */
+	void restartOscillator();
+private:
+
+};
+
+}