protocol.h File Reference

PX4IO interface protocol. More...

#include <inttypes.h>

Go to the source code of this file.

Classes
struct	px4io_mixdata
	As-needed mixer data upload. More...
struct	IOPacket

Macros
#define	REG_TO_SIGNED(_reg)   ((int16_t)(_reg))
#define	SIGNED_TO_REG(_signed)   ((uint16_t)(_signed))
#define	REG_TO_FLOAT(_reg)   ((float)REG_TO_SIGNED(_reg) / 10000.0f)
#define	FLOAT_TO_REG(_float)   SIGNED_TO_REG((int16_t)floorf((_float + 0.00005f) * 10000.0f))
#define	REG_TO_BOOL(_reg)   ((bool)(_reg))
#define	PX4IO_PROTOCOL_VERSION   4
#define	PX4IO_PROTOCOL_MAX_CONTROL_COUNT   8
	The protocol does not support more than set here, individual units might support less - see PX4IO_P_CONFIG_CONTROL_COUNT.
#define	PX4IO_PAGE_CONFIG   0
#define	PX4IO_P_CONFIG_PROTOCOL_VERSION   0 /* PX4IO_PROTOCOL_VERSION */
#define	PX4IO_P_CONFIG_HARDWARE_VERSION   1 /* magic numbers TBD */
#define	PX4IO_P_CONFIG_BOOTLOADER_VERSION   2 /* get this how? */
#define	PX4IO_P_CONFIG_MAX_TRANSFER   3 /* maximum I2C transfer size */
#define	PX4IO_P_CONFIG_CONTROL_COUNT   4 /* hardcoded max control count supported */
#define	PX4IO_P_CONFIG_ACTUATOR_COUNT   5 /* hardcoded max actuator output count */
#define	PX4IO_P_CONFIG_RC_INPUT_COUNT   6 /* hardcoded max R/C input count supported */
#define	PX4IO_P_CONFIG_ADC_INPUT_COUNT   7 /* hardcoded max ADC inputs */
#define	PX4IO_P_CONFIG_RELAY_COUNT   8 /* hardcoded # of relay outputs */
#define	PX4IO_MAX_TRANSFER_LEN   64
#define	PX4IO_PAGE_STATUS   1
#define	PX4IO_P_STATUS_FREEMEM   0
#define	PX4IO_P_STATUS_CPULOAD   1
#define	PX4IO_P_STATUS_FLAGS   2 /* monitoring flags */
#define	PX4IO_P_STATUS_FLAGS_OUTPUTS_ARMED   (1 << 0) /* arm-ok and locally armed */
#define	PX4IO_P_STATUS_FLAGS_OVERRIDE   (1 << 1) /* in manual override */
#define	PX4IO_P_STATUS_FLAGS_RC_OK   (1 << 2) /* RC input is valid */
#define	PX4IO_P_STATUS_FLAGS_RC_PPM   (1 << 3) /* PPM input is valid */
#define	PX4IO_P_STATUS_FLAGS_RC_DSM   (1 << 4) /* DSM input is valid */
#define	PX4IO_P_STATUS_FLAGS_RC_SBUS   (1 << 5) /* SBUS input is valid */
#define	PX4IO_P_STATUS_FLAGS_FMU_OK   (1 << 6) /* controls from FMU are valid */
#define	PX4IO_P_STATUS_FLAGS_RAW_PWM   (1 << 7) /* raw PWM from FMU is bypassing the mixer */
#define	PX4IO_P_STATUS_FLAGS_MIXER_OK   (1 << 8) /* mixer is OK */
#define	PX4IO_P_STATUS_FLAGS_ARM_SYNC   (1 << 9) /* the arming state between IO and FMU is in sync */
#define	PX4IO_P_STATUS_FLAGS_INIT_OK   (1 << 10) /* initialisation of the IO completed without error */
#define	PX4IO_P_STATUS_FLAGS_FAILSAFE   (1 << 11) /* failsafe is active */
#define	PX4IO_P_STATUS_FLAGS_SAFETY_OFF   (1 << 12) /* safety is off */
#define	PX4IO_P_STATUS_FLAGS_FMU_INITIALIZED   (1 << 13) /* FMU was initialized and OK once */
#define	PX4IO_P_STATUS_FLAGS_RC_ST24   (1 << 14) /* ST24 input is valid */
#define	PX4IO_P_STATUS_FLAGS_RC_SUMD   (1 << 15) /* SUMD input is valid */
#define	PX4IO_P_STATUS_ALARMS   3 /* alarm flags - alarms latch, write 1 to a bit to clear it */
#define	PX4IO_P_STATUS_ALARMS_VBATT_LOW   (1 << 0) /* [1] VBatt is very close to regulator dropout */
#define	PX4IO_P_STATUS_ALARMS_TEMPERATURE   (1 << 1) /* board temperature is high */
#define	PX4IO_P_STATUS_ALARMS_SERVO_CURRENT   (1 << 2) /* [1] servo current limit was exceeded */
#define	PX4IO_P_STATUS_ALARMS_ACC_CURRENT   (1 << 3) /* [1] accessory current limit was exceeded */
#define	PX4IO_P_STATUS_ALARMS_FMU_LOST   (1 << 4) /* timed out waiting for controls from FMU */
#define	PX4IO_P_STATUS_ALARMS_RC_LOST   (1 << 5) /* timed out waiting for RC input */
#define	PX4IO_P_STATUS_ALARMS_PWM_ERROR   (1 << 6) /* PWM configuration or output was bad */
#define	PX4IO_P_STATUS_ALARMS_VSERVO_FAULT   (1 << 7) /* [2] VServo was out of the valid range (2.5 - 5.5 V) */
#define	PX4IO_P_STATUS_VSERVO   6 /* [2] servo rail voltage in mV */
#define	PX4IO_P_STATUS_VRSSI   7 /* [2] RSSI voltage */
#define	PX4IO_P_STATUS_PRSSI   8 /* [2] RSSI PWM value */
#define	PX4IO_P_STATUS_MIXER   9 /* mixer actuator limit flags */
#define	PX4IO_PAGE_ACTUATORS   2 /* 0..CONFIG_ACTUATOR_COUNT-1 */
#define	PX4IO_PAGE_SERVOS   3 /* 0..CONFIG_ACTUATOR_COUNT-1 */
#define	PX4IO_PAGE_RAW_RC_INPUT   4
#define	PX4IO_P_RAW_RC_COUNT   0 /* number of valid channels */
#define	PX4IO_P_RAW_RC_FLAGS   1 /* RC detail status flags */
#define	PX4IO_P_RAW_RC_FLAGS_FRAME_DROP   (1 << 0) /* single frame drop */
#define	PX4IO_P_RAW_RC_FLAGS_FAILSAFE   (1 << 1) /* receiver is in failsafe mode */
#define	PX4IO_P_RAW_RC_FLAGS_RC_DSM11   (1 << 2) /* DSM decoding is 11 bit mode */
#define	PX4IO_P_RAW_RC_FLAGS_MAPPING_OK   (1 << 3) /* Channel mapping is ok */
#define	PX4IO_P_RAW_RC_FLAGS_RC_OK   (1 << 4) /* RC reception ok */
#define	PX4IO_P_RAW_RC_NRSSI   2 /* [2] Normalized RSSI value, 0: no reception, 255: perfect reception */
#define	PX4IO_P_RAW_RC_DATA   3 /* [1] + [2] Details about the RC source (PPM frame length, Spektrum protocol type) */
#define	PX4IO_P_RAW_FRAME_COUNT   4 /* Number of total received frames (wrapping counter) */
#define	PX4IO_P_RAW_LOST_FRAME_COUNT   5 /* Number of total dropped frames (wrapping counter) */
#define	PX4IO_P_RAW_RC_BASE   6 /* CONFIG_RC_INPUT_COUNT channels from here */
#define	PX4IO_PAGE_RC_INPUT   5
#define	PX4IO_P_RC_VALID   0 /* bitmask of valid controls */
#define	PX4IO_P_RC_BASE   1 /* CONFIG_RC_INPUT_COUNT controls from here */
#define	PX4IO_PAGE_RAW_ADC_INPUT   6 /* 0..CONFIG_ADC_INPUT_COUNT-1 */
#define	PX4IO_PAGE_PWM_INFO   7
#define	PX4IO_RATE_MAP_BASE   0 /* 0..CONFIG_ACTUATOR_COUNT bitmaps of PWM rate groups */
#define	PX4IO_PAGE_SETUP   50
#define	PX4IO_P_SETUP_FEATURES   0
#define	PX4IO_P_SETUP_FEATURES_SBUS1_OUT   (1 << 0)
	enable S.Bus v1 output
#define	PX4IO_P_SETUP_FEATURES_SBUS2_OUT   (1 << 1)
	enable S.Bus v2 output
#define	PX4IO_P_SETUP_FEATURES_PWM_RSSI   (1 << 2)
	enable PWM RSSI parsing
#define	PX4IO_P_SETUP_FEATURES_ADC_RSSI   (1 << 3)
	enable ADC RSSI parsing
#define	PX4IO_P_SETUP_ARMING   1 /* arming controls */
#define	PX4IO_P_SETUP_ARMING_IO_ARM_OK   (1 << 0) /* OK to arm the IO side */
#define	PX4IO_P_SETUP_ARMING_FMU_ARMED   (1 << 1) /* FMU is already armed */
#define	PX4IO_P_SETUP_ARMING_MANUAL_OVERRIDE_OK   (1 << 2) /* OK to switch to manual override via override RC channel */
#define	PX4IO_P_SETUP_ARMING_FAILSAFE_CUSTOM   (1 << 3) /* use custom failsafe values, not 0 values of mixer */
#define	PX4IO_P_SETUP_ARMING_INAIR_RESTART_OK   (1 << 4) /* OK to try in-air restart */
#define	PX4IO_P_SETUP_ARMING_ALWAYS_PWM_ENABLE   (1 << 5) /* Output of PWM right after startup enabled to help ESCs initialize and prevent them from beeping */
#define	PX4IO_P_SETUP_ARMING_RC_HANDLING_DISABLED   (1 << 6) /* Disable the IO-internal evaluation of the RC */
#define	PX4IO_P_SETUP_ARMING_LOCKDOWN   (1 << 7) /* If set, the system operates normally, but won't actuate any servos */
#define	PX4IO_P_SETUP_ARMING_FORCE_FAILSAFE   (1 << 8) /* If set, the system will always output the failsafe values */
#define	PX4IO_P_SETUP_ARMING_TERMINATION_FAILSAFE   (1 << 9) /* If set, the system will never return from a failsafe, but remain in failsafe once triggered. */
#define	PX4IO_P_SETUP_ARMING_OVERRIDE_IMMEDIATE   (1 << 10) /* If set then on FMU failure override is immediate. Othewise it waits for the mode switch to go past the override thrshold */
#define	PX4IO_P_SETUP_PWM_RATES   2 /* bitmask, 0 = low rate, 1 = high rate */
#define	PX4IO_P_SETUP_PWM_DEFAULTRATE   3 /* 'low' PWM frame output rate in Hz */
#define	PX4IO_P_SETUP_PWM_ALTRATE   4 /* 'high' PWM frame output rate in Hz */
#define	PX4IO_P_SETUP_RELAYS_PAD   5
#define	PX4IO_P_SETUP_VSERVO_SCALE   6 /* hardware rev [2] servo voltage correction factor (float) */
#define	PX4IO_P_SETUP_DSM   7 /* DSM bind state */
#define	PX4IO_P_SETUP_SET_DEBUG   9 /* debug level for IO board */
#define	PX4IO_P_SETUP_REBOOT_BL   10 /* reboot IO into bootloader */
#define	PX4IO_REBOOT_BL_MAGIC   14662 /* required argument for reboot (random) */
#define	PX4IO_P_SETUP_CRC   11 /* get CRC of IO firmware */
#define	PX4IO_P_SETUP_FORCE_SAFETY_OFF
#define	PX4IO_P_SETUP_RC_THR_FAILSAFE_US   13
	the throttle failsafe pulse length in microseconds
#define	PX4IO_P_SETUP_FORCE_SAFETY_ON   14 /* force safety switch into 'disarmed' (PWM disabled state) */
#define	PX4IO_FORCE_SAFETY_MAGIC   22027 /* required argument for force safety (random) */
#define	PX4IO_P_SETUP_PWM_REVERSE   15
	Bitmask to reverse PWM channels 1-8.
#define	PX4IO_P_SETUP_TRIM_ROLL   16
	Roll trim, in actuator units.
#define	PX4IO_P_SETUP_TRIM_PITCH   17
	Pitch trim, in actuator units.
#define	PX4IO_P_SETUP_TRIM_YAW   18
	Yaw trim, in actuator units.
#define	PX4IO_P_SETUP_SCALE_ROLL   19
	Roll scale, in actuator units.
#define	PX4IO_P_SETUP_SCALE_PITCH   20
	Pitch scale, in actuator units.
#define	PX4IO_P_SETUP_SCALE_YAW   21
	Yaw scale, in actuator units.
#define	PX4IO_P_SETUP_SBUS_RATE   22 /* frame rate of SBUS1 output in Hz */
#define	PX4IO_P_SETUP_MOTOR_SLEW_MAX   24 /* max motor slew rate */
#define	PX4IO_P_SETUP_THR_MDL_FAC   25 /* factor for modelling static pwm output to thrust relationship */
#define	PX4IO_P_SETUP_THERMAL   26 /* thermal management */
#define	PX4IO_P_SETUP_AIRMODE   27 /* air-mode */
#define	PX4IO_THERMAL_IGNORE   UINT16_MAX
#define	PX4IO_THERMAL_OFF   0
#define	PX4IO_THERMAL_FULL   10000
#define	PX4IO_PAGE_CONTROLS   51
	actuator control groups, one after the other, 8 wide
#define	PX4IO_P_CONTROLS_GROUP_0   (PX4IO_PROTOCOL_MAX_CONTROL_COUNT * 0)
	0..PX4IO_PROTOCOL_MAX_CONTROL_COUNT - 1
#define	PX4IO_P_CONTROLS_GROUP_1   (PX4IO_PROTOCOL_MAX_CONTROL_COUNT * 1)
	0..PX4IO_PROTOCOL_MAX_CONTROL_COUNT - 1
#define	PX4IO_P_CONTROLS_GROUP_2   (PX4IO_PROTOCOL_MAX_CONTROL_COUNT * 2)
	0..PX4IO_PROTOCOL_MAX_CONTROL_COUNT - 1
#define	PX4IO_P_CONTROLS_GROUP_3   (PX4IO_PROTOCOL_MAX_CONTROL_COUNT * 3)
	0..PX4IO_PROTOCOL_MAX_CONTROL_COUNT - 1
#define	PX4IO_P_CONTROLS_GROUP_VALID   64
#define	PX4IO_P_CONTROLS_GROUP_VALID_GROUP0   (1 << 0)
	group 0 is valid / received
#define	PX4IO_P_CONTROLS_GROUP_VALID_GROUP1   (1 << 1)
	group 1 is valid / received
#define	PX4IO_P_CONTROLS_GROUP_VALID_GROUP2   (1 << 2)
	group 2 is valid / received
#define	PX4IO_P_CONTROLS_GROUP_VALID_GROUP3   (1 << 3)
	group 3 is valid / received
#define	PX4IO_PAGE_MIXERLOAD   52
#define	PX4IO_PAGE_RC_CONFIG   53
	R/C input configuration.
#define	PX4IO_P_RC_CONFIG_MIN   0
	lowest input value
#define	PX4IO_P_RC_CONFIG_CENTER   1
	center input value
#define	PX4IO_P_RC_CONFIG_MAX   2
	highest input value
#define	PX4IO_P_RC_CONFIG_DEADZONE   3
	band around center that is ignored
#define	PX4IO_P_RC_CONFIG_ASSIGNMENT   4
	mapped input value
#define	PX4IO_P_RC_CONFIG_ASSIGNMENT_MODESWITCH   100
	magic value for mode switch
#define	PX4IO_P_RC_CONFIG_OPTIONS   5
	channel options bitmask
#define	PX4IO_P_RC_CONFIG_OPTIONS_ENABLED   (1 << 0)
#define	PX4IO_P_RC_CONFIG_OPTIONS_REVERSE   (1 << 1)
#define	PX4IO_P_RC_CONFIG_STRIDE   6
	spacing between channel config data
#define	PX4IO_PAGE_DIRECT_PWM   54
	0..CONFIG_ACTUATOR_COUNT-1
#define	PX4IO_PAGE_FAILSAFE_PWM   55
	0..CONFIG_ACTUATOR_COUNT-1
#define	PX4IO_PAGE_SENSORS   56
	Sensors connected to PX4IO.
#define	PX4IO_P_SENSORS_ALTITUDE   0
	Altitude of an external sensor (HoTT or S.BUS2)
#define	PX4IO_PAGE_TEST   127
#define	PX4IO_P_TEST_LED   0
	set the amber LED on/off
#define	PX4IO_PAGE_CONTROL_MIN_PWM   106
	0..CONFIG_ACTUATOR_COUNT-1
#define	PX4IO_PAGE_CONTROL_MAX_PWM   107
	0..CONFIG_ACTUATOR_COUNT-1
#define	PX4IO_PAGE_CONTROL_TRIM_PWM   108
	0..CONFIG_ACTUATOR_COUNT-1
#define	PX4IO_PAGE_DISARMED_PWM   109 /* 0..CONFIG_ACTUATOR_COUNT-1 */
#define	F2I_MIXER_MAGIC   0x6d74
#define	F2I_MIXER_ACTION_RESET   0
#define	F2I_MIXER_ACTION_APPEND   1
#define	PKT_MAX_REGS   32
	Serial protocol encapsulation.
#define	PKT_CODE_READ   0x00 /* FMU->IO read transaction */
#define	PKT_CODE_WRITE   0x40 /* FMU->IO write transaction */
#define	PKT_CODE_SUCCESS   0x00 /* IO->FMU success reply */
#define	PKT_CODE_CORRUPT   0x40 /* IO->FMU bad packet reply */
#define	PKT_CODE_ERROR   0x80 /* IO->FMU register op error reply */
#define	PKT_CODE_MASK   0xc0
#define	PKT_COUNT_MASK   0x3f
#define	PKT_COUNT(_p)   ((_p).count_code & PKT_COUNT_MASK)
#define	PKT_CODE(_p)   ((_p).count_code & PKT_CODE_MASK)
#define	PKT_SIZE(_p)   ((size_t)((uint8_t *)&((_p).regs[PKT_COUNT(_p)]) - ((uint8_t *)&(_p))))

Enumerations
enum	{   dsm_bind_power_down = 0, dsm_bind_power_up, dsm_bind_set_rx_out, dsm_bind_send_pulses,   dsm_bind_reinit_uart }

Detailed Description

PX4IO interface protocol.

Author

Lorenz Meier loren.nosp@m.z@px.nosp@m.4.io

Communication is performed via writes to and reads from 16-bit virtual registers organised into pages of 255 registers each.

The first two bytes of each write select a page and offset address respectively. Subsequent reads and writes increment the offset within the page.

Some pages are read- or write-only.

Note that some pages may permit offset values greater than 255, which can only be achieved by long writes. The offset does not wrap.

Writes to unimplemented registers are ignored. Reads from unimplemented registers return undefined values.

As convention, values that would be floating point in other parts of the PX4 system are expressed as signed integer values scaled by 10000, e.g. control values range from -10000..10000. Use the REG_TO_SIGNED and SIGNED_TO_REG macros to convert between register representation and the signed version, and REG_TO_FLOAT/FLOAT_TO_REG to convert to float.

Note that the implementation of readable pages prefers registers within readable pages to be densely packed. Page numbers do not need to be packed.

Definitions marked [1] are only valid on PX4IOv1 boards. Likewise, [2] denotes definitions specific to the PX4IOv2 board.

Macro Definition Documentation

PX4IO_P_SETUP_FORCE_SAFETY_OFF

#define PX4IO_P_SETUP_FORCE_SAFETY_OFF

Value:

12  /* force safety switch into
                                                           'armed' (PWM enabled) state - this is a non-data write and
                                                           hence index 12 can safely be used. */