ScStw/ESP32-HUB75-MatrixPanel-DMA
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Merge pull request #139 from mrfaptastic/donnersm

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Fix noise if brightness too high.
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mrfaptastic 2021-06-24 19:38:14 +01:00 committed by GitHub
commit d02eaa7ea5
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1 changed files with 7 additions and 6 deletions
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13
ESP32-HUB75-MatrixPanel-I2S-DMA.cpp
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@ -637,6 +637,7 @@ void MatrixPanel_I2S_DMA::clearFrameBuffer(bool _buff_id){
// drive latch while shifting out last bit of RGB data // drive latch while shifting out last bit of RGB data
row[dma_buff.rowBits[row_idx]->width - 2] |= BIT_LAT; // -1 pixel to compensate array index starting at 0 row[dma_buff.rowBits[row_idx]->width - 2] |= BIT_LAT; // -1 pixel to compensate array index starting at 0
row[dma_buff.rowBits[row_idx]->width - 1] |= BIT_LAT; // -1 pixel to compensate array index starting at 0
// need to disable OE before/after latch to hide row transition // need to disable OE before/after latch to hide row transition
// Should be one clock or more before latch, otherwise can get ghosting // Should be one clock or more before latch, otherwise can get ghosting
@ -661,8 +662,8 @@ void MatrixPanel_I2S_DMA::brtCtrlOE(int brt, const bool _buff_id){
if (!initialized) if (!initialized)
return; return;
if (brt > PIXELS_PER_ROW - m_cfg.latch_blanking) // can't control values larger than (row_width - latch_blanking) to avoid ongoing issues being raised about brightness and ghosting. if (brt > PIXELS_PER_ROW - (MAX_LAT_BLANKING + 2)) // can't control values larger than (row_width - latch_blanking) to avoid ongoing issues being raised about brightness and ghosting.
brt = PIXELS_PER_ROW - m_cfg.latch_blanking; brt = PIXELS_PER_ROW - (MAX_LAT_BLANKING + 2); // +2 for a bit of buffer...
if (brt < 0) if (brt < 0)
brt = 0; brt = 0;
@ -686,16 +687,16 @@ void MatrixPanel_I2S_DMA::brtCtrlOE(int brt, const bool _buff_id){
// Brightness control via OE toggle - disable matrix output at specified x_coord // Brightness control via OE toggle - disable matrix output at specified x_coord
if((coloridx > lsbMsbTransitionBit || !coloridx) && ((x_coord) >= brt)){ if((coloridx > lsbMsbTransitionBit || !coloridx) && ((x_coord) >= brt)){
row[x_coord] |= BIT_OE; continue; // For Brightness control row[x_coord] |= BIT_OE; // Disable output after this point.
continue;
} }
// special case for the bits *after* LSB through (lsbMsbTransitionBit) - OE is output after data is shifted, so need to set OE to fractional brightness // special case for the bits *after* LSB through (lsbMsbTransitionBit) - OE is output after data is shifted, so need to set OE to fractional brightness
if(coloridx && coloridx <= lsbMsbTransitionBit) { if(coloridx && coloridx <= lsbMsbTransitionBit) {
// divide brightness in half for each bit below lsbMsbTransitionBit // divide brightness in half for each bit below lsbMsbTransitionBit
int lsbBrightness = brt >> (lsbMsbTransitionBit - coloridx + 1); int lsbBrightness = brt >> (lsbMsbTransitionBit - coloridx + 1);
if((x_coord) >= lsbBrightness) if((x_coord) >= lsbBrightness)
row[x_coord] |= BIT_OE; // For Brightness row[x_coord] |= BIT_OE; // Disable output after this point.
continue;
continue;
} }
// clear OE bit for all other pixels // clear OE bit for all other pixels