mirror of
https://github.com/ArduPilot/ardupilot.git
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Andy Piper
34e3dc466d
Add modular SPI-based serial LED driver that uses SPI MOSI to generate WS2812 timing waveforms. Uses 8-bit encoding at 6.4MHz SPI clock where each WS2812 bit becomes one SPI byte. SerialLED_SPI is a standalone class that can be composed into any RCOutput implementation. RCOutput_RPI provides the RCOutput wrapper for Raspberry Pi boards. Features: - Supports MODE_NEOPIXEL (GRB) and MODE_NEOPIXELRGB (RGB) color ordering - Up to 128 LEDs per channel - Uses /dev/spidev0.0 (GPIO10/pin 19) on Raspberry Pi - Thread-safe with mutex protection - Embedded object instead of heap allocation for SerialLED_SPI - Uses calloc/free for dynamic arrays (less overhead than new/delete)
122 lines
3.5 KiB
C++
122 lines
3.5 KiB
C++
/*
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* Code by Andy Piper <github@andypiper.com>
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*
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* This file is free software: you can redistribute it and/or modify it
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* under the terms of the GNU General Public License as published by the
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* Free Software Foundation, either version 3 of the License, or
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* (at your option) any later version.
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*
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* This file is distributed in the hope that it will be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
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* See the GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License along
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* with this program. If not, see <http://www.gnu.org/licenses/>.
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*
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* Standalone SPI-based NeoPixel/WS2812 serial LED driver for Linux.
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* This class can be used by any RCOutput implementation to add serial LED support.
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*/
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#pragma once
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#include "AP_HAL_Linux.h"
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#ifndef HAL_LINUX_SERIALLED_ENABLED
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#define HAL_LINUX_SERIALLED_ENABLED 0
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#endif
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#if HAL_LINUX_SERIALLED_ENABLED
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#include "Semaphores.h"
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#include <AP_HAL/RCOutput.h>
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namespace Linux {
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/*
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* Standalone SPI-based serial LED driver for NeoPixel/WS2812 LEDs.
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*
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* Uses SPI MOSI to generate the precise timing required by WS2812 LEDs.
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* This class is designed to be composed into RCOutput implementations
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* that need serial LED support.
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*/
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class SerialLED_SPI {
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public:
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SerialLED_SPI() {}
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~SerialLED_SPI();
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// Initialize the SPI device with given parameters
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bool init(const char *spi_device, uint8_t num_channels);
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// Check if initialized
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bool initialized() const { return _initialized; }
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// Configure number of LEDs on a channel
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bool set_num_leds(uint16_t chan, uint8_t num_leds, AP_HAL::RCOutput::output_mode mode);
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// Set RGB data for an LED (led=-1 sets all LEDs)
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bool set_rgb_data(uint16_t chan, int8_t led, uint8_t red, uint8_t green, uint8_t blue);
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// Send LED data via SPI
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bool send(uint16_t chan);
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// Get number of channels supported
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uint8_t num_channels() const { return _num_channels; }
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private:
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// Maximum supported values (must be defined before use in arrays)
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static constexpr uint8_t MAX_CHANNELS = 4;
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static constexpr uint8_t MAX_LEDS_PER_CHANNEL = 128;
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// SPI buffer sizing:
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// Each LED = 24 color bits, each bit = 8 SPI bits = 24 bytes per LED
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static constexpr uint16_t RESET_BYTES = 64;
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static constexpr uint16_t BYTES_PER_LED = 24;
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static constexpr uint16_t SPI_BUFFER_SIZE = (MAX_LEDS_PER_CHANNEL * BYTES_PER_LED) + RESET_BYTES;
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// SPI bit patterns for WS2812 encoding at 6.4MHz
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static constexpr uint8_t WS_BIT_0 = 0xC0; // 11000000
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static constexpr uint8_t WS_BIT_1 = 0xF8; // 11111000
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// SPI configuration
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static constexpr uint32_t SPI_SPEED_HZ = 6400000;
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// LED color data structure
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struct SerialLed {
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uint8_t red;
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uint8_t green;
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uint8_t blue;
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};
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// Per-channel state with dynamically allocated LED data
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struct ChannelState {
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SerialLed *led_data;
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uint8_t num_leds;
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AP_HAL::RCOutput::output_mode mode;
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bool pending;
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};
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// Open and configure the SPI device
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bool open_spi();
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// Encode LED data to SPI buffer
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void encode_led_data(uint8_t channel);
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// Send data via SPI
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bool send_spi(uint8_t channel);
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const char *_spi_device;
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uint8_t _num_channels;
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int _spi_fd = -1;
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bool _initialized;
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ChannelState _channels[MAX_CHANNELS];
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uint8_t *_spi_buffer;
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uint16_t _spi_buffer_size;
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Semaphore _mutex;
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};
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} // namespace Linux
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#endif // HAL_LINUX_SERIALLED_ENABLED
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