I've been translating Adafruit's driver for ST7735 and saw some commands regarding power control. Here's the command code:
static const uint8_t PROGMEM
Bcmd[] = { // Initialization commands for 7735B screens
18, // 18 commands in list:
ST7735_SWRESET, DELAY, // 1: Software reset, no args, w/delay
50, // 50 ms delay
ST7735_SLPOUT , DELAY, // 2: Out of sleep mode, no args, w/delay
255, // 255 = 500 ms delay
ST7735_COLMOD , 1+DELAY, // 3: Set color mode, 1 arg + delay:
0x05, // 16-bit color
10, // 10 ms delay
ST7735_FRMCTR1, 3+DELAY, // 4: Frame rate control, 3 args + delay:
0x00, // fastest refresh
0x06, // 6 lines front porch
0x03, // 3 lines back porch
10, // 10 ms delay
ST7735_MADCTL , 1 , // 5: Memory access ctrl (directions), 1 arg:
0x08, // Row addr/col addr, bottom to top refresh
ST7735_DISSET5, 2 , // 6: Display settings #5, 2 args, no delay:
0x15, // 1 clk cycle nonoverlap, 2 cycle gate
// rise, 3 cycle osc equalize
0x02, // Fix on VTL
ST7735_INVCTR , 1 , // 7: Display inversion control, 1 arg:
0x0, // Line inversion
ST7735_PWCTR1 , 2+DELAY, // 8: Power control, 2 args + delay:
0x02, // GVDD = 4.7V
0x70, // 1.0uA
10, // 10 ms delay
ST7735_PWCTR2 , 1 , // 9: Power control, 1 arg, no delay:
0x05, // VGH = 14.7V, VGL = -7.35V
ST7735_PWCTR3 , 2 , // 10: Power control, 2 args, no delay:
0x01, // Opamp current small
0x02, // Boost frequency
ST7735_VMCTR1 , 2+DELAY, // 11: Power control, 2 args + delay:
0x3C, // VCOMH = 4V
0x38, // VCOML = -1.1V
10, // 10 ms delay
ST7735_PWCTR6 , 2 , // 12: Power control, 2 args, no delay:
0x11, 0x15,
ST7735_GMCTRP1,16 , // 13: Magical unicorn dust, 16 args, no delay:
0x09, 0x16, 0x09, 0x20, // (seriously though, not sure what
0x21, 0x1B, 0x13, 0x19, // these config values represent)
0x17, 0x15, 0x1E, 0x2B,
0x04, 0x05, 0x02, 0x0E,
ST7735_GMCTRN1,16+DELAY, // 14: Sparkles and rainbows, 16 args + delay:
0x0B, 0x14, 0x08, 0x1E, // (ditto)
0x22, 0x1D, 0x18, 0x1E,
0x1B, 0x1A, 0x24, 0x2B,
0x06, 0x06, 0x02, 0x0F,
10, // 10 ms delay
ST7735_CASET , 4 , // 15: Column addr set, 4 args, no delay:
0x00, 0x02, // XSTART = 2
0x00, 0x81, // XEND = 129
ST7735_RASET , 4 , // 16: Row addr set, 4 args, no delay:
0x00, 0x02, // XSTART = 1
0x00, 0x81, // XEND = 160
ST7735_NORON , DELAY, // 17: Normal display on, no args, w/delay
10, // 10 ms delay
ST7735_DISPON , DELAY, // 18: Main screen turn on, no args, w/delay
255 }, // 255 = 500 ms delay
Rcmd1[] = { // Init for 7735R, part 1 (red or green tab)
15, // 15 commands in list:
ST7735_SWRESET, DELAY, // 1: Software reset, 0 args, w/delay
150, // 150 ms delay
ST7735_SLPOUT , DELAY, // 2: Out of sleep mode, 0 args, w/delay
255, // 500 ms delay
ST7735_FRMCTR1, 3 , // 3: Frame rate ctrl - normal mode, 3 args:
0x01, 0x2C, 0x2D, // Rate = fosc/(1x2+40) * (LINE+2C+2D)
ST7735_FRMCTR2, 3 , // 4: Frame rate control - idle mode, 3 args:
0x01, 0x2C, 0x2D, // Rate = fosc/(1x2+40) * (LINE+2C+2D)
ST7735_FRMCTR3, 6 , // 5: Frame rate ctrl - partial mode, 6 args:
0x01, 0x2C, 0x2D, // Dot inversion mode
0x01, 0x2C, 0x2D, // Line inversion mode
ST7735_INVCTR , 1 , // 6: Display inversion ctrl, 1 arg, no delay:
0x07, // No inversion
ST7735_PWCTR1 , 3 , // 7: Power control, 3 args, no delay:
0xA2,
0x02, // -4.6V
0x84, // AUTO mode
ST7735_PWCTR2 , 1 , // 8: Power control, 1 arg, no delay:
0xC5, // VGH25 = 2.4C VGSEL = -10 VGH = 3 * AVDD
ST7735_PWCTR3 , 2 , // 9: Power control, 2 args, no delay:
0x0A, // Opamp current small
0x00, // Boost frequency
ST7735_PWCTR4 , 2 , // 10: Power control, 2 args, no delay:
0x8A, // BCLK/2, Opamp current small & Medium low
0x2A,
ST7735_PWCTR5 , 2 , // 11: Power control, 2 args, no delay:
0x8A, 0xEE,
ST7735_VMCTR1 , 1 , // 12: Power control, 1 arg, no delay:
0x0E,
ST7735_INVOFF , 0 , // 13: Don't invert display, no args, no delay
ST7735_MADCTL , 1 , // 14: Memory access control (directions), 1 arg:
0xC8, // row addr/col addr, bottom to top refresh
ST7735_COLMOD , 1 , // 15: set color mode, 1 arg, no delay:
0x05 }, // 16-bit colorThe parts where it says ST7735_PWCTRx are problematic. Why is there -4.6V? There's no negative voltage! Negative voltage kills AVR, no? And this is probably for 5V Arduinos. What about 3.3V XMEGAs? This should probably be lower, but how much lower? I don't wanna burn my screen by setting up something wrong. What's with this?:
VGH = 14.7V, VGL = -7.35V
No such board has that big voltage!! Why is this here? Do I have to change it? Sounds like it's gonna be a big explosion. I've been reading the datasheet, but it says it's a derivation of this and that and blah blah oh my... Calculus and analog electronics. My enemies.
So do I need to change that for my 3.3V XMEGA?