Overview

Counter module with optional wrap around

Discussion

This module counts up starting from 0 at a specified rate in milliseconds. The count value is output as an integer value on the output pin. The module has an input pin whose only purpose is to get the current sample rate and blockSize. This information is used to determine the time base for the processing. The sample rate of the output pin equals the sample rate of the input divided by the input block size.

The module determine time by counting input samples. The hidden variable .sampleCounterPeriod equals the number of samples which most closely approximates .incTime.

The module variable .wrap can be used to implement circular wrapping. If .wrap = 0, then no wrapping is performed. If .wrap = N, then the module counts up to N-1 and then wraps to 0.

The internal module counter is initialized to 0 and the module outputs the sequence 0, 1, 2, ..., N-1, 0, 1, 2, ..., N-1, 0, etc.

When muted the module outputs all zeros. When bypassed the module continues to run.

Type Definition

typedef struct _ModuleCounter
{
    ModuleInstanceDescriptor instance;            // Common Audio Weaver module instance structure
    FLOAT32 incTime;                              // Time in msec to wait between increments
    UINT32 wrap;                                  // Counting is performed modulo this value
    UINT32 count;                                 // Current counter value
    UINT32 sampleCounter;                         // Internal variable used to maintain time
    UINT32 sampleCounterPeriod;                   // Number of samples corresponding to incTime
} ModuleCounterClass;

Variables

Properties

Name	Type	Usage	isHidden	Default value	Range	Units
incTime	float	parameter	0	1000	0:10000	msec
wrap	uint	parameter	0	5	Unrestricted
count	uint	state	0	0	Unrestricted
sampleCounter	uint	state	1	0	Unrestricted
sampleCounterPeriod	uint	state	1	48000	Unrestricted

Pins

Input Pins

Name: in

Description: Ignored input

Data type: {float, int, fract32}

Channel range: Unrestricted

Block size range: Unrestricted

Sample rate range: Unrestricted

Complex support: Real

Output Pins

Name: count

Description: Count value

Data type: int

MATLAB Usage

File Name: counter_module.m

 M = counter_module(NAME)
 Audio Weaver module which counts up, and wraps around, at a specified
 rate.  The count value is output on a pin.  Arguments:
    NAME - name of the module