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Initialization.md

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Initialization Sequence

This is a documentation of the initialization sequence found in the official example code.

0x36 - MADCTL: Memory Data Access Control

Values: 0x00

Bits:

  • 7: MY - Page Address Order
    • 0: Top to Bottom (selected)
    • 1: Bottom to Top
  • 6: MX - Column Address Order
    • 0: Left to Right (selected)
    • 1: Right to Left
  • 5: MV - Page/Column Order
    • 0: Normal (selected)
    • 1: Reverse Mode
  • 4: ML - Line Address Order
    • 0: LCD Refresh Top to Bottom (selected)
    • 1: LCD Refresh Bottom to Top
  • 3: RGB - BRGB/BGR Order
    • 0: RGB
    • 1: BGR
  • 2: MH - Display Data Latch Order
    • 0: LCD Refresh Left to Right
    • 1: LCD Refresh Right to Left

0x3A - COLMOD: Interface Pixel Format

Values: 0x05

Bits:

  • 6:4: RGB interface color format
    • 101: 65K of RGB interface
    • 110: 262K of RGB interface
    • 0: Undocumented value which is used here?
  • 2:0: Control interface color format
    • 011: 12bit/pixel
    • 101: 16bit/pixel (selected)
    • 110: 18bit/pixel
    • 111: 16M truncated

The "RGB interface color format" isn't set here; the datasheet suggests using 0x55 for our purposes... Need to check what is going on here.

0xB2 - PORCTRL: Porch Setting

Values: 0x0C 0x0C 0x00 0x33 0x33

Probably empirically gained values for the porch settings, let's keep them. "Separate porch control" is disabled.

0xB7 - GCTRL: Gate Control

Values: 0x35

Bits:

  • 6:4: VGH Setting (Voltage)
    • 0: 12.2 V
    • 1: 12.54 V
    • 2: 12.89 V
    • 3: 13.26 V
    • 4: 13.65 V
    • 5: 14.06 V
    • 6: 14.5 V
    • 7: 14.97 V
  • 2:0: VGL Setting (Voltage)
    • 0: -7.16 V
    • 1: -7.67 V
    • 2: -8.23 V
    • 3: -8.87 V
    • 4: -9.6 V
    • 5: -10.43 V
    • 6: -11.38 V
    • 7: -12.5 V

0xBB - VCOMS: VCOM Setting

Values: 0x19

0x19 -> 0.725 V

0xC0 - LCMCTRL: LCM Control

Values: 0x2C

Bits:

  • 6: XMY: XOR MY setting in command 36h
  • 5: XBGR: XOR RGB setting in command 36h (selected)
  • 4: XREV: XOR inverse setting in command 21h
  • 3: XMH: this bit can reverse source output order and only support for RGB interface without RAM mode (selected)
  • 2: XMV: XOR MV setting in command 36h (selected)
  • 1: XMX: XOR MX setting in command 36h
  • 0: XGS: XOR GS setting in command E4h

0xC2 - VDVVRHEN: VDV and VRH Command Enable

Values: 0x01

  • 0: VDV and VRH register value comes from NVM.
  • 1: VDV and VRH register value comes from command write (selected).

0xC3 - VRHS: VRH Set

Values: 0x12

0x12 -> VAP: 4.45+( vcom+vcom offset+vdv) 0x12 -> VAN: -4.45+( vcom+vcom offset-vdv)

0xC4 - VDVS: VDV Set

Values: 0x20

0x20 -> VDV: 0 V

0xC6 - FRCTRL2: Frame Rate Control in Normal Mode

Values: 0x0F

Bits:

  • 4:0: RTNA
    • 0x0F -> 60 Hz
  • 7:5: NLA - Inversion selection in normal mode
    • 0x0: dot inversion (selected).
    • 0x7: column inversion.

0xD0 - PWCTRL1: Power Control 1

Values: 0xA4 0xA1

0xA4 is a fixed parameter?

Second Parameter Bits:

  • 7:6: AVDD, 2 -> 6.8 V
  • 5:4: AVCL, 2 -> -4.8 V
  • 1:0: VDS, 1 -> 2.3 V

0xE0 - PVGAMCTRL: Positive Voltage Gamma Control

Values: 0xD0 0x04 0x0D 0x11 0x13 0x2B 0x3F 0x54 0x4C 0x18 0x0D 0x0B 0x1F 0x23

Gamma Curve, probably calibrated for this device...

0xE1 - NVGAMCTRL: Negative Voltage Gamma Control

Values: 0xD0 0x04 0x0C 0x11 0x13 0x2C 0x3F 0x44 0x51 0x2F 0x1F 0x1F 0x20 0x23

Gamma Curve, probably calibrated for this device...

0x21 - INVON: Display Inversion On

Self-explaining...

0x11 - SLPOUT: Sleep Out

Self-explaining...

Interestingly, other drivers have added a delay after sending SLPOUT but here this is not the case. Maybe the timing allows for this here?

0x29 - DISPON: Display On

Self-explaining...