Channel Class Reference

Channels are modules that store the machine's positional state. More...

#include <channels.hpp>

Inheritance diagram for Channel:

Public Member Functions
void	begin ()
	Initialize the Channel with no output port. Not for normal use.
void	begin (OutputPort *target_output_port, uint8_t output_signal)
	Initialize the Channel with a target OutputPort and output signal.
void	set_max_pulse_rate (float max_pulses_per_sec)
	Sets the maxium allowable pulse rate for the channel.
void	set_ratio (float input_units, float channel_units=1.0)
	Sets the transmission ratio for all target transmissions.
void	set_upper_limit (DecimalPosition upper_limit_input_units)
	Sets the upper position limit for the channel. Useful if you want the channel to stop transmitting motion streams at a certain upper threshold.
void	set_lower_limit (DecimalPosition lower_limit_input_units)
	Sets the lower position limit for the channel. Useful if you want the channel to stop transmitting motion streams at a certain lower threshold.
void	disable_upper_limit ()
	Disables the upper position limit.
void	disable_lower_limit ()
	Disables the lower position limit.
void	disable_limits ()
	Disables the channel.
void	disable ()
	Disables the channel.
void	enable ()
	Enables the channel.
void	enable_filtering (uint16_t num_samples=20)
	Enables a moving average filter with a specified sample window. The bigger the window, the smoother the output but the less responsive the motion.
void	disable_filtering ()
	Disables the moving average filter.
int8_t	is_outside_limits ()
	Checks if the current channel position is outside the set limits.
void	invert_output ()
	Inverts the channel output direction.
void	invert_output (bool invert)
	Inverts the channel output direction. Useful for reversing motor direction without changing wiring.

Public Attributes
DecimalPosition	target_position
	Target position of the channel in pulses. Target positon is what the channel is driving toward.
DecimalPosition	current_position
	Current position of the channel in pulses. Current position is where the channel is currently at.
DecimalPosition	filtered_target_position
	Filtered target position of the channel in pulses. This is used when the enableFiltering() method is used to smooth out motion.
bool	filtering_on = false
	Flag indicating whether filtering is enabled for the channel.

Detailed Description

Channels are modules that store the machine's positional state.

A Channel directly interfaces with an OutputPort by mapping to a particular signal flag (e.g. "X").Channels contain a target position variable that can be modified by upstream components such as motion generators. They also contain a variable representing their current position. Each interrupt frame, the channel increments or decrements the current position when needed to drive |target-current| < 0.5, and correspondingly sets step and direction flags on its mapped OutputPort. Any number of channels can be instantiated, often corresponding to axes of the machine machine. Basic Modules may contain multiple channels that map to distinct flags on the same OutputPort. Driver Modules typically have multiple channels that each map to a unique OutputPort, that then generate step/direction signals for a motor drive module. Here's an example of how to instantiate and configure a Channel and map it to an OutputPort:

  #define module_driver
#include "stepdance.hpp"
 
Channel channel_x;
OutputPort output_x;    
 
void setup() {
  // -- Configure and start the output port --
  output_x.begin(OUTPUT_A); // "OUTPUT_A" specifies the physical port on the PCB for the output.
    // -- Configure and start the channels --
  channel_x.begin(&output_x, SIGNAL_X); // Connects the channel to the "X" signal on "output_x".
                                        // We choose the "X" signal because it results in a step pulse of 2us,
                                        // which is more than long enough for the driver IC
  channel_x.set_ratio(40, 3200); // Sets the input/output transmission ratio for the channel.
} 
 
void loop(){
dance_loop();
}

Member Function Documentation

begin()

void Channel::begin	(	OutputPort *	target_output_port,
		uint8_t	output_signal )

Initialize the Channel with a target OutputPort and output signal.

Parameters

target_output_port	Pointer to the target OutputPort.
output_signal	Index of the output signal (SIGNAL_X, SIGNAL_Y, etc.).

disable_limits()

void Channel::disable_limits ( )

inline

Disables the channel.

Disables all position limits.

enable_filtering()

void Channel::enable_filtering

(

uint16_t

num_samples = 20

)

Enables a moving average filter with a specified sample window. The bigger the window, the smoother the output but the less responsive the motion.

Parameters

num_samples

Number of samples for filtering. Default is 20.

invert_output() [1/2]

void Channel::invert_output

(

)

Inverts the channel output direction.

Inverts the channel output direction. Useful for reversing motor direction without changing wiring.

invert_output() [2/2]

void Channel::invert_output

(

bool

invert

)

Inverts the channel output direction. Useful for reversing motor direction without changing wiring.

Parameters

invert

If true, inverts the output direction; if false, restores the normal direction.

is_outside_limits()

int8_t Channel::is_outside_limits

(

)

Checks if the current channel position is outside the set limits.

Returns

int8_t Returns 0 if inside limits, 1 if outside upper limit, or -1 if outside lower limit.

set_lower_limit()

void Channel::set_lower_limit

(

DecimalPosition

lower_limit_input_units

)

Sets the lower position limit for the channel. Useful if you want the channel to stop transmitting motion streams at a certain lower threshold.

Parameters

lower_limit_input_units

Lower limit in input (world) units.

set_max_pulse_rate()

void Channel::set_max_pulse_rate

(

float

max_pulses_per_sec

)

Sets the maxium allowable pulse rate for the channel.

Parameters

max_pulses_per_sec

Maximum allowable pulse rate in pulses per second.

set_ratio()

void Channel::set_ratio	(	float	input_units,
		float	channel_units = 1.0 )

Sets the transmission ratio for all target transmissions.

Parameters

input_units	Number of input units corresponding to channel_units.
channel_units	Number of channel units corresponding to input_units. Default is 1.0.

set_upper_limit()

void Channel::set_upper_limit

(

DecimalPosition

upper_limit_input_units

)

Sets the upper position limit for the channel. Useful if you want the channel to stop transmitting motion streams at a certain upper threshold.

Parameters

upper_limit_input_units

Upper limit in input (world) units.

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The documentation for this class was generated from the following file:

• lib/channels.hpp