diff --git a/ESP32-HUB75-MatrixPanel-I2S-DMA.cpp b/ESP32-HUB75-MatrixPanel-I2S-DMA.cpp index 586092c..0c7dc8d 100644 --- a/ESP32-HUB75-MatrixPanel-I2S-DMA.cpp +++ b/ESP32-HUB75-MatrixPanel-I2S-DMA.cpp @@ -791,91 +791,50 @@ void MatrixPanel_I2S_DMA::shiftDriver(const shift_driver _drv, const int dma_r1_ #if SERIAL_DEBUG Serial.println( F("MatrixPanel_I2S_DMA - initializing FM6124 driver...")); #endif - int C12[16] = {0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1}; - int C13[16] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0}; + bool REG1[16] = {0,0,0,0,0, 1,1,1,1,1,1, 0,0,0,0,0}; // this sets global matrix brighness power + bool REG2[16] = {0,0,0,0,0, 0,0,0,0,1,0, 0,0,0,0,0}; // a single bit enables the matrix output - pinMode(dma_r1_pin, OUTPUT); - pinMode(dma_g1_pin, OUTPUT); - pinMode(dma_b1_pin, OUTPUT); - pinMode(dma_r2_pin, OUTPUT); - pinMode(dma_g2_pin, OUTPUT); - pinMode(dma_b2_pin, OUTPUT); - pinMode(dma_a_pin, OUTPUT); - pinMode(dma_b_pin, OUTPUT); - pinMode(dma_c_pin, OUTPUT); - pinMode(dma_d_pin, OUTPUT); - pinMode(dma_e_pin, OUTPUT); - pinMode(dma_clk_pin, OUTPUT); - pinMode(dma_lat_pin, OUTPUT); - pinMode(dma_oe_pin, OUTPUT); + for (uint8_t _pin:{dma_r1_pin, dma_r2_pin, dma_g1_pin, dma_g2_pin, dma_b1_pin, dma_b2_pin, dma_clk_pin, dma_lat_pin, dma_oe_pin}) + pinMode(_pin, OUTPUT); - // Send Data to control register 11 - digitalWrite(dma_oe_pin, HIGH); // Display reset + digitalWrite(dma_oe_pin, HIGH); // Disable Display digitalWrite(dma_lat_pin, LOW); digitalWrite(dma_clk_pin, LOW); + + // Send Data to control register REG1 + // this sets the matrix brightness actually for (int l = 0; l < MATRIX_WIDTH; l++){ - int y = l % 16; - digitalWrite(dma_r1_pin, LOW); - digitalWrite(dma_g1_pin, LOW); - digitalWrite(dma_b1_pin, LOW); - digitalWrite(dma_r2_pin, LOW); - digitalWrite(dma_g2_pin, LOW); - digitalWrite(dma_b2_pin, LOW); + for (uint8_t _pin:{dma_r1_pin, dma_r2_pin, dma_g1_pin, dma_g2_pin, dma_b1_pin, dma_b2_pin}) + digitalWrite(_pin, REG1[l%16]); // we have 16 bits shifters and write the same value all over the matrix array - if (C12[y] == 1){ - digitalWrite(dma_r1_pin, HIGH); - digitalWrite(dma_g1_pin, HIGH); - digitalWrite(dma_b1_pin, HIGH); - digitalWrite(dma_r2_pin, HIGH); - digitalWrite(dma_g2_pin, HIGH); - digitalWrite(dma_b2_pin, HIGH); - } - - if (l > MATRIX_WIDTH - 12){ + if (l > MATRIX_WIDTH - 12){ // pull the latch 12 clocks before the end of matrix so that REG1 starts counting to save the value digitalWrite(dma_lat_pin, HIGH); - } else { - digitalWrite(dma_lat_pin, LOW); } - - digitalWrite(dma_clk_pin, HIGH); + digitalWrite(dma_clk_pin, HIGH); // 1-clock pulse digitalWrite(dma_clk_pin, LOW); } + // drop the latch and save data to the REG1 all over the FM6124 chips digitalWrite(dma_lat_pin, LOW); digitalWrite(dma_clk_pin, LOW); - // Send Data to control register 12 + // Send Data to control register REG2 (enable LED output) for (int l = 0; l < MATRIX_WIDTH; l++){ - int y = l % 16; - digitalWrite(dma_r1_pin, LOW); - digitalWrite(dma_g1_pin, LOW); - digitalWrite(dma_b1_pin, LOW); - digitalWrite(dma_r2_pin, LOW); - digitalWrite(dma_g2_pin, LOW); - digitalWrite(dma_b2_pin, LOW); + for (uint8_t _pin:{dma_r1_pin, dma_r2_pin, dma_g1_pin, dma_g2_pin, dma_b1_pin, dma_b2_pin}) + digitalWrite(_pin, REG2[l%16]); // we have 16 bits shifters and we write the same value all over the matrix array - if (C13[y] == 1){ - digitalWrite(dma_r1_pin, HIGH); - digitalWrite(dma_g1_pin, HIGH); - digitalWrite(dma_b1_pin, HIGH); - digitalWrite(dma_r2_pin, HIGH); - digitalWrite(dma_g2_pin, HIGH); - digitalWrite(dma_b2_pin, HIGH); - } - - if (l > MATRIX_WIDTH - 13){ + if (l > MATRIX_WIDTH - 13){ // pull the latch 13 clocks before the end of matrix so that reg2 stars counting to save the value digitalWrite(dma_lat_pin, HIGH); - } else { - digitalWrite(dma_lat_pin, LOW); } - digitalWrite(dma_clk_pin, HIGH); + digitalWrite(dma_clk_pin, HIGH); // 1-clock pulse digitalWrite(dma_clk_pin, LOW); } + // drop the latch and save data to the REG1 all over the FM6126 chips digitalWrite(dma_lat_pin, LOW); digitalWrite(dma_clk_pin, LOW); - break; } + break; case SHIFT: default: break; diff --git a/FM6126A.md b/FM6126A.md new file mode 100644 index 0000000..ac4d395 --- /dev/null +++ b/FM6126A.md @@ -0,0 +1,68 @@ +## The mystery of control registers for FM6126A chips + + + +Datasheet for this chis chip is in chineese and does not shed a light on what those two control regs are. + +An excellent insight could be found here + +https://github.com/hzeller/rpi-rgb-led-matrix/issues/746#issuecomment-453860510 + + + + +So there are two regs - **REG1** and **REG1**, + +one could be written with 12 clock pusles (and usually called reg12, dunno why :)) + +the other one could be written with 13 clock pusles (and usually called reg13, dunno why :)) + + + +So I've done some measurmens on power consumption while toggling bits of **REG1** and it looks that it could provide a fine grained brighness control over matrix. + +There are 6 bits (6 to 11) giving an increased brighness (compared to all-zeroes) and 4 bits (2-5) giving decreased brighness!!! + + + +So it seems that the most bright (and hungry for power) value is + +bool REG1[16] = {0,0,0,0,0, 1,1,1,1,1,1, 0,0,0,0,0}; and not {0,1,1,1,1, 1,1,1,1,1,1, 1,1,1,1,1} as it is usually used. + +I'm not sure about bit 1 - it is either not used or I was unable to measure it's influence to brightness/power. + + + +Giving at least 10 bits of hardware brightness control opens pretty nice options for offloading. Should dig into this more deeper. + + + +Here are some of the measurments I've took for 2 64x64 panels filled with white color - reg value and corresponding current drain in amps. + + + +|REG1 |bit value|Current, amps | +|--|--|--| +|REG1| 0111111 00000| >5 amps| +|REG1| 0100010 00000| 3.890 amp| +|REG1| 0100000 00000| 3.885 amp| +|REG1| 0011110 00000| 3.640 amp| +|REG1| 0011100 00000| 3.620 amp| +|REG1| 0011000 00000| 3.240 amp| +|REG1| 0010010 00000| 2.520 amp| +|REG1| 0010001 00000| 2.518 amp| +|REG1| 0010001 10000| 2.493 amp| +|REG1| 0010000 00000| 2.490 amp| +|REG1| 0010000 11110| 2.214 amp| +|REG1| 0001100 00000| 2.120 amp| +|REG1| 0001000 00000| 1.750 amp| +|REG1| 0000100 00000| 1.375 amp| +|REG1| 0000010 00000| 1.000 amp| +|REG1| **0000000 00000**| 0.995 amp| +|REG1| 0000001 11111| 0.700 amp| +|REG1| 0000000 01111| 0.690 amp| +|REG1| 0000000 10000| 0.690 amp| +|REG1| 0000000 11110| 0.686 amp| + + +/Vortigont/ \ No newline at end of file