Added IR Lib, samples and specification

firmware/libs/CMakeLists.txt

@@ -2,4 +2,5 @@
 # Build ble_mgmt and thread_mgmt first since lasertag_utils depends on them
 add_subdirectory(ble_mgmt)
 add_subdirectory(thread_mgmt)
-add_subdirectory(lasertag_utils)
+add_subdirectory(lasertag_utils)
+add_subdirectory(ir_send)

firmware/libs/Kconfig

@@ -1,4 +1,5 @@
 # Main entry point for custom project Kconfigs
 rsource "lasertag_utils/Kconfig"
 rsource "thread_mgmt/Kconfig"
-rsource "ble_mgmt/Kconfig"
+rsource "ble_mgmt/Kconfig"
+rsource "ir_send/Kconfig"

firmware/libs/ir_send/CMakeLists.txt

@@ -0,0 +1,5 @@
+if(CONFIG_IR_SEND)
+  zephyr_library()
+  zephyr_sources(src/ir_send.c)
+  zephyr_include_directories(include)
+endif()

firmware/libs/ir_send/Kconfig

@@ -0,0 +1,61 @@
+config IR_SEND
+	bool "IR Send Library"
+	help
+	  Enable IR transmission library for laser tag system.
+	  Provides PWM-based IR carrier generation with pulse-distance coding.
+
+if IR_SEND
+
+menu "IR Protocol Configuration"
+
+config IR_SEND_CARRIER_HZ
+	int "IR carrier frequency (Hz)"
+	default 38000
+	range 30000 45000
+	help
+	  Carrier frequency for PWM generation. Standard value is 38 kHz
+	  for TSOP48xx receivers. Adjust only if using different receivers.
+
+config IR_SEND_DUTY_CYCLE_PERCENT
+	int "Carrier duty cycle (%)"
+	default 50
+	range 25 75
+	help
+	  PWM duty cycle percentage. Some receivers prefer 33%, others 50%.
+	  Default 50% works with most TSOP-series receivers.
+
+config IR_SEND_MARK_US
+	int "Mark duration (microseconds)"
+	default 600
+	range 300 1000
+	help
+	  Duration of carrier burst (mark) for each bit. Standard is 600 µs
+	  following Sony SIRC timing.
+
+config IR_SEND_SPACE0_US
+	int "Space duration for bit 0 (microseconds)"
+	default 600
+	range 300 1000
+	help
+	  Carrier-off duration (space) after mark for logical 0.
+	  Default 600 µs creates 1.2 ms total bit time.
+
+config IR_SEND_SPACE1_US
+	int "Space duration for bit 1 (microseconds)"
+	default 1200
+	range 800 2000
+	help
+	  Carrier-off duration (space) after mark for logical 1.
+	  Default 1200 µs creates 1.8 ms total bit time.
+
+config IR_SEND_START_BURST_US
+	int "Start burst duration (microseconds)"
+	default 2400
+	range 1500 4000
+	help
+	  Initial synchronization burst at frame start. Receivers detect
+	  this to sync on incoming frames. Default 2400 µs = 4× mark time.
+
+endmenu
+
+endif

firmware/libs/ir_send/include/ir_send.h

@@ -0,0 +1,45 @@
+#ifndef IR_SEND_H
+#define IR_SEND_H
+
+/**
+ * @file ir_send.h
+ * @brief Infrared transmission library for laser tag system.
+ */
+
+#include <stdint.h>
+
+/**
+ * @brief Initialize IR output hardware (PWM backend).
+ * @return 0 on success, negative error code otherwise.
+ */
+int ir_send_init(void);
+
+/**
+ * @brief Send a single IR pulse (carrier burst).
+ * @param duration_us Pulse duration in microseconds.
+ * @return 0 on success.
+ */
+int ir_send_pulse(uint32_t duration_us);
+
+/**
+ * @brief Send a carrier burst of given duration (us) at configured frequency.
+ * @param burst_us Duration in microseconds.
+ * @return 0 on success.
+ */
+int ir_send_burst_us(uint32_t burst_us);
+
+/**
+ * @brief Send IR message (sequence of pulses and gaps).
+ * @param data IR payload (e.g., shooter ID, power-up type).
+ * @param len Length of data in bytes.
+ * @return 0 on success.
+ */
+int ir_send_message(const uint8_t *data, uint8_t len);
+
+/**
+ * @brief Set IR carrier frequency.
+ * @param freq_hz Carrier frequency in Hz (typically 38000 Hz).
+ */
+void ir_send_set_frequency(uint32_t freq_hz);
+
+#endif /* IR_SEND_H */

firmware/libs/ir_send/src/ir_send.c

@@ -0,0 +1,78 @@
+/*
+ * IR Send Library - PWM-based carrier generation
+ */
+
+#include <zephyr/kernel.h>
+#include <zephyr/logging/log.h>
+#include <zephyr/drivers/pwm.h>
+
+#include "ir_send.h"
+
+LOG_MODULE_REGISTER(ir_send_lib);
+
+static const struct pwm_dt_spec ir_pwm = PWM_DT_SPEC_GET(DT_ALIAS(ir_output));
+static uint32_t carrier_freq = 38000; /* Standard IR carrier frequency in Hz */
+
+int ir_send_init(void)
+{
+	if (!device_is_ready(ir_pwm.dev)) {
+		LOG_ERR("IR PWM device not ready!");
+		return -ENODEV;
+	}
+
+	LOG_INF("IR output PWM ready: dev=%p, channel=%u", ir_pwm.dev, ir_pwm.channel);
+	return 0;
+}
+
+int ir_send_pulse(uint32_t duration_us)
+{
+	return ir_send_burst_us(duration_us);
+}
+
+int ir_send_message(const uint8_t *data, uint8_t len)
+{
+	if (!device_is_ready(ir_pwm.dev)) {
+		return -ENODEV;
+	}
+
+	LOG_DBG("Sending IR message (%u bytes)", len);
+	
+	/* TODO: Implement IR protocol encoding (e.g., NEC, custom protocol)
+	 * For now, just a placeholder that sends a test pulse.
+	 */
+	ir_send_pulse(1000); /* 1ms test pulse */
+
+	return 0;
+}
+
+void ir_send_set_frequency(uint32_t freq_hz)
+{
+	carrier_freq = freq_hz;
+	LOG_DBG("IR carrier frequency set to %u Hz", carrier_freq);
+}
+
+int ir_send_burst_us(uint32_t burst_us)
+{
+	if (!device_is_ready(ir_pwm.dev)) {
+		return -ENODEV;
+	}
+
+	uint64_t period_ns = PWM_HZ(carrier_freq);
+	uint64_t duty_ns = period_ns / 2U; /* 50% duty cycle */
+
+	int ret = pwm_set_dt(&ir_pwm, period_ns, duty_ns);
+	if (ret != 0) {
+		LOG_ERR("Failed to enable PWM burst: %d", ret);
+		return ret;
+	}
+
+	k_usleep(burst_us);
+
+	/* Stop carrier after burst */
+	ret = pwm_set_dt(&ir_pwm, period_ns, 0);
+	if (ret != 0) {
+		LOG_ERR("Failed to stop PWM after burst: %d", ret);
+	}
+
+	return ret;
+}