VUMeter.c

Go to the documentation of this file.

/*
 * VUMeter.c
 *
 *  Created on: May 30, 2016
 *      Author: Torsten
 */

#include "VUMeter.h"

/* the VU meter variables */
static t_VUparams l_params;
static int16_t last_input[NUM_CHANNELS];

void VUMETER_Analyse(void)
{
    int16_t *sampleBuf, sample;
    int bufLen;

    bufLen = AUDIO_PLAYER_GetBuffer((uint8_t **)&sampleBuf);
    if (AUDIO_PLAYER_GetState())
    {
        //second buffer was played - now the first is active
        sampleBuf += bufLen / (2 + sizeof(int16_t));
    }
    else
    {
        //first buffer was played - now the second is active
    }

    bufLen /= (2 + sizeof(int16_t));            //in words, for half-buffer
    while (bufLen > 0)
    {
        sample = *sampleBuf++;
        if ( ! (sample & 0x8000))
        {
            if (sample > l_params.vuInput[0])
                l_params.vuInput[0] = sample;
        }
        sample = *sampleBuf++;
        if ( ! (sample & 0x8000))
        {
            if (sample > l_params.vuInput[1])
                l_params.vuInput[1] = sample;
        }
        bufLen -= 2;
    }
}

void VUMETER_Input(int channel)
{
    if (l_params.vuInput[channel] > last_input[channel])        // update if higher input level
        last_input[channel] = l_params.vuInput[channel];
    if (l_params.vuInput[channel] > l_params.vuPeak[channel])   // set peak hold
        l_params.vuPeak[channel] = l_params.vuInput[channel];
}

static void VUMETER_Move(int channel)
{
    uint32_t curTick = HAL_GetTick();
    uint32_t curTickDelta;

    if (curTick > l_params.vuTick[channel] )
        curTickDelta = curTick - l_params.vuTick[channel];
    else
        curTickDelta = l_params.vuTick[channel] - curTick;

    if (curTickDelta > LEVELMOVE)
    {
        l_params.vuInput[channel] -= l_params.vuInput[channel] >> 4;
        l_params.vuTick[channel] = curTick;
    }

    if (curTick > l_params.vuTickPeak[channel])
        curTickDelta = curTick - l_params.vuTickPeak[channel];
    else
        curTickDelta = l_params.vuTickPeak[channel] - curTick;
    if (curTickDelta > PEAKHOLD)        // reset peak hold after 2000ms
    {
        l_params.vuPeak[channel] = l_params.vuInput[channel];
        l_params.vuTickPeak[channel] = curTick;
    }
}

void VUMETER_Display(int channel)
{
    // Scale to make it fit to number of segments
    uint8_t Level = (l_params.vuInput[channel] / (MAX_VALUE / SEGMENTS));
    uint8_t Peak  = (l_params.vuPeak [channel] / (MAX_VALUE / SEGMENTS));
    int i;
    int colSet = 0;

    for (i = 0; i < (SEGMENTS); i++)
    {
        if (Level > i)
        {
            if (i == (SEGMENTS - 3))
                BSP_LCD_SetTextColor(LCD_COLOR_RED);
            else
            if (i == (SEGMENTS - 6))
                BSP_LCD_SetTextColor(LCD_COLOR_YELLOW);
            else
            {
                if ( ! (colSet & 1))
                {
                    BSP_LCD_SetTextColor(LCD_COLOR_GREEN);
                    colSet |= 1;
                }
            }
        }
        else
        {
            if ( ! (colSet & 2))
            {
                BSP_LCD_SetTextColor(LCD_COLOR_GRAY);
                colSet |= 2;
            }
        }

        BSP_LCD_FillRect(X_START + i * (X_WIDTH + XY_GAP), Y_START + channel * (Y_WIDTH + XY_GAP), X_WIDTH, Y_WIDTH); // draw rectangles from left to right
    }

    //draw the peak marker
    BSP_LCD_SetTextColor(LCD_COLOR_MAGENTA);
    if (Peak >= SEGMENTS)
        Peak--;
    BSP_LCD_FillRect(X_START + Peak * (X_WIDTH + XY_GAP), Y_START + channel * (Y_WIDTH + XY_GAP), X_WIDTH, Y_WIDTH);  // draw peak value

    //move the peak markers
    VUMETER_Move(channel);
}