ChiTu F X connection diagram

This page describes the result of measurements, which pin is connected to where.

There is online not much information available about the ChiTu F X board. The following pdf is what I collected from a search through the internet:

List of components:

STM32F446: Microcontroller, https://www.st.com/resource/en/datasheet/stm32f446mc.pdf
TMC2209: Stepper driver, https://www.trinamic.com/fileadmin/assets/Products/ICs_Documents/TMC2209_Datasheet_V103.pdf
WSF40N06 N-Ch. Mosfet, https://datasheet.lcsc.com/lcsc/1809291408_Winsok-Semicon-WSF40N06_C86291.pdf
3.5“ TFT display module. Most likely¹⁾ it is the Solomon Systech SSD1963. A datasheet of the Solomon Systech SSD1963 can be found here: Solomon-Systech-LCD-Controller-Data-Sheet.pdf. Also, I ordered a 3.5” TFT display from Chitusystems and it is compatible to and works on the Chitu FX board.
- XPT2046 Touchscreen controller: https://www.dzsc.com/uploadfile/company/785710/20111014212155973.pdf
- (Original: TSC2046E-Q1 Touchscreen controller: https://www.ti.com/lit/ds/symlink/tsc2046e-q1.pdf)
- Schematics of Chitu tronxy x5sa with 40 pin display: https://github.com/MarlinFirmware/Marlin/files/3401484/x5sa-main_board-2.pdf ²⁾
- Similar lcd projects:
  - https://mydiyelectronics.wordpress.com/tag/lcd/
  - http://www.lcdwiki.com/res/MRB3511/3.5inch_8&16BIT_Module_MRB3511_User_Manual_EN.pdf

A logic analyzer capture of the communication between printer controller and lcd controller: (png images, 4.2MB) can be found here:

https://www.auditeon.com/xyz/projects/chitu_fx_lcd_display_communication.zip

Connection diagram
ChiTu F X series
V4.3
191205-FX

U8
 IC:STM32F446ZET6, LQFP 144 pin
  54 PF14 -> U6_E1,P.2 (E1-EN)
  47 PB1 -> U6_E1,P.16 (E1-STP)
  53 PF13 -> U6_E1,P.19 (E1-DIR)
  89 PG4 -> U6_E2,P.2 (E2-EN)
  82 PD13 -> U6_E2,P.16 (E2-STP)
  90 PG5 -> U6_E2,P.19 (E2-DIR)
  10 PF0 -> U6_X,P.2 (X-EN)
  04 PE5 -> U6_X,P.16 (X-STP)
  11 PF1 -> U6_X,P.19 (X-DIR)
  15 PF5 -> U6_Y,P.2 (Y-EN)
  21 PF9 -> U6_Y,P.16 (Y-STP)
  13 PF3 -> U6_Y,P.19 (Y-DIR)
  41 PA5 -> U6_Z,P.2 (Z-EN)
  42 PA6 -> U6_Z,P.16 (Z-STP)
  55 PF15 -> U6_Z,P.19 (Z-DIR)
  93 PG8 -> Q5,P.G (E1_HOT)
 110 PA15 -> Q20,P.G (E2_HOT)
  73 PB12 -> U4,P.12 (LCD RESET)
  85 PD14 -> U4,P.35 (LCD D0)
  86 PD15 -> U4,P.34 (LCD D1)
 114 PD0  -> U4,P.33 (LCD D2
 115 PD1  -> U4,P.32 (LCD D3)
  58 PE7  -> U4,P.26 (LCD D4)
  63 PE8  -> U4,P.11 (LCD D5)
  60 PE9  -> U4,P.10 (LCD D6)
  63 PE10 -> U4,P.9  (LCD D7)
  64 PE11 -> U4,P.25 (LCD D8)
  65 PE12 -> U4,P.24 (LCD D9)
  66 PE13 -> U4,P.23 (LCD D10)
  67 PE14 -> U4,P.22 (LCD D11)
  68 PE15 -> U4,P.21 (LCD D12)
  77 PD8  -> U4,P.20 (LCD D13)
  78 PD9  -> U4,P.10 (LCD D14)
  79 PD10 -> U4,P.18 (LCD D15)               
  73 PB12 -> U4,P.12 (LCD RESET)
  etc. (See below)
  
>>>>>>>>>>>>>
Todo:
13 XPT2046,P.16 SPI1-SCK
14 XPT2046,P.15 SPI1-_CS
15 XPT2046,P.14 SPI1-MOSI
16 XPT2046,P.12 SPI1-MISO
17 XPT2046,P.11 SPI1-INT
27 -> (U8,P.93/PG8) LIGHT PWM #B4
28 -> (U8,P.118/PD4) LCD-nOE #B3
29 -> (U8,P.119/PD5) LCD-nWE #B2 (Active low) ??
30 -> (U8,P.87/PG2) RS #B1
31 -> (U8,P.127/PG12) PS-CLK #B0 / Chip select ??
<<<<<<<<<<<<<<

U6_E1
 IC:TMC2209-LA
  01 OB2 (E1-MOTOR,P.2B)
  02 ENN (U8,P.54/PF14)
  03 GND
  04 CPO
  05 CPI
  06 VCP
  07 SPREAD
  08 5VOUT
  09 MS1_AD0
  10 MS2_AD1
  11 DIAG
  12 INDEX
  13 CLK
  14 PDN_UART
  15 VCC_IO
  16 STEP (U8,P.47/PB1)
  17 VREF
  18 GND
  19 DIR (U8,P.53/PF13)
  20 STDBY
  21 OA2 (E1-MOTOR,P.1B)
  22 VS
  23 BRA
  24 OA1 (E1-MOTOR,P.1A)
  25 .
  26 OB1 (E1-MOTOR,P.2A)
  27 BRB
  28 VS

U6_E2
 IC:TMC2209-LA
  01 OB2 (E2/EXT-MOTOR,P.2B)
  02 ENN (U8,P.89/PG4)
  03 GND
  04 CPO
  05 CPI
  06 VCP
  07 SPREAD
  08 5VOUT
  09 MS1_AD0
  10 MS2_AD1
  11 DIAG
  12 INDEX
  13 CLK
  14 PDN_UART
  15 VCC_IO
  16 STEP (U8,P.82/PD13)
  17 VREF
  18 GND
  19 DIR (U8,P.90/PG5)
  20 STDBY
  21 OA2 (E2/EXT-MOTOR,P.1B)
  22 VS
  23 BRA
  24 OA1 (E2/EXT-MOTOR,P.1A)
  25 .
  26 OB1 (E2/EXT-MOTOR,P.2A)
  27 BRB
  28 VS

U6_X
 IC:TMC2209-LA
  01 OB2 (X-MOTOR,P.2B)
  02 ENN (U8,P.10/PF0)
  03 GND
  04 CPO
  05 CPI
  06 VCP
  07 SPREAD
  08 5VOUT
  09 MS1_AD0
  10 MS2_AD1
  11 DIAG
  12 INDEX
  13 CLK
  14 PDN_UART
  15 VCC_IO
  16 STEP (U8,P.04/PE5)
  17 VREF
  18 GND
  19 DIR (U8,P.11/PF1)
  20 STDBY
  21 OA2 (X-MOTOR,P.1B)
  22 VS
  23 BRA
  24 OA1 (X-MOTOR,P.1A)
  25 .
  26 OB1 (X-MOTOR,P.2A)
  27 BRB
  28 VS

U6_Y
 IC:TMC2209-LA
  01 OB2 (Y-MOTOR,P.2B)
  02 ENN (U8,P.15/PF5)
  03 GND
  04 CPO
  05 CPI
  06 VCP
  07 SPREAD
  08 5VOUT
  09 MS1_AD0
  10 MS2_AD1
  11 DIAG
  12 INDEX
  13 CLK
  14 PDN_UART
  15 VCC_IO
  16 STEP (U8,P.21/PF9)
  17 VREF
  18 GND
  19 DIR (U8,P.13/PF3)
  20 STDBY
  21 OA2 (Y-MOTOR,P.1B)
  22 VS
  23 BRA
  24 OA1 (Y-MOTOR,P.1A)
  25 .
  26 OB1 (Y-MOTOR,P.2A)
  27 BRB
  28 VS

U6_Z
 IC:TMC2209-LA
  01 OB2 (Z-MOTOR,P.2B)
  02 ENN (U8,P.41/PA5)
  03 GND
  04 CPO
  05 CPI
  06 VCP
  07 SPREAD
  08 5VOUT
  09 MS1_AD0
  10 MS2_AD1
  11 DIAG
  12 INDEX
  13 CLK
  14 PDN_UART
  15 VCC_IO
  16 STEP (U8,P.42/PA6)
  17 VREF
  18 GND
  19 DIR (U8,P.55/PF15)
  20 STDBY
  21 OA2 (Z-MOTOR,P.1B)
  22 VS
  23 BRA
  24 OA1 (Z-MOTOR,P.1A)
  25 .
  26 OB1 (Z-MOTOR,P.2A)
  27 BRB
  28 VS

E1-MOTOR
 J:4 pin JST conn
  1B U6-E1,P.21
  1A U6-E1,P.24
  2A U6-E1,P.26
  2B U6-E1,P.1

E2/EXT-MOTOR
 J:4 pin JST conn
  1B U6-E2,P.21
  1A U6-E2,P.24
  2A U6-E2,P.26
  2B U6-E2,P.1

X-MOTOR
 J:4 pin JST conn
  1B U6-X,P.21
  1A U6-X,P.24
  2A U6-X,P.26
  2B U6-X,P.1

Y-MOTOR
 J:4 pin JST conn
  1B U6-Y,P.21
  1A U6-Y,P.24
  2A U6-Y,P.26
  2B U6-Y,P.1

Z-MOTOR
 J:4 pin JST conn
  1B U6-Z,P.21
  1A U6-Z,P.24
  2A U6-Z,P.26
  2B U6-Z,P.1

E1_HOT
 J:2-pin screw terminal 5.08mm
  E1 GND
  HOT <- Q5,P.D
 
E2_HOT
 J:2-pin screw terminal 5.08mm
  E2 GND
  HOT

Q5
 TR:WSF40N06, N-Ch. Mosfet (60v, 20mOhm, 50A)
  G <- R42,P.1 + U8,P.93 (PG8)
  D -> E1_HOT,P.HOT
  S <- +12/24V

R42
 R:01C (10k, 1%)
  1 Q5,P.G
  2 GND

Q20
 TR:WSF40N06, N-Ch. Mosfet (60v, 20mOhm, 50A)
  G <- R21,P.1 + U8,P.110 (PA15)
  D -> E2_HOT,P.HOT
  S <- +12/24V

R21
 R:01C (10k, 1%)
  1 Q20,P.G
  2 GND

3.5" TFT Display "V4.13"

Below is the pinout from the FPC cable (FPC-350C40119V1)

Please note that logic analyzer pin is given after #-character

Connector U4

 1 VCC_3.3V
 2 VCC_3.3V
 3 VCC_3.3V
 4 VCC_5V
 5 VCC_5V
 6 GND
 7 GND
 8 GND
 9 -> (U8,P.63/PE10) D7 #A7
10 -> (U8,P.60/PE9) D6 #A6
11 -> (U8,P.63/PE8) D5 #A5
12 -> (U8,P.73/PB12) LCD RESET #B5
13 XPT2046,P.16 SPI1-SCK
14 XPT2046,P.15 SPI1-_CS
15 XPT2046,P.14 SPI1-MOSI
16 XPT2046,P.12 SPI1-MISO
17 XPT2046,P.11 SPI1-INT
18 -> (U8,P.79/PD10) D15 #A15
19 -> (U8,P.78/PD9) D14 #A14
20 -> (U8,P.77/PD8) D13 #A13
21 -> (U8,P.68/PE15) D12 #A12
22 -> (U8,P.67/PE14) D11 #A11
23 -> (U8,P.66/PE13) D10 #A10
24 -> (U8,P.65/PE12) D9 #A9
25 -> (U8,P.64/PE11) D8 #A8
26 -> (U8,P.58/PE7) D4 #A4
27 -> (U8,P.93/PG8) LIGHT PWM #B4
28 -> (U8,P.118/PD4) LCD-nOE #B3
29 -> (U8,P.119/PD5) LCD-nWE #B2 (Active low) ??
30 -> (U8,P.87/PG2) RS #B1
31 -> (U8,P.127/PG12) PS-CLK #B0 / Chip select ??
32 -> (U8,P.115/PD1) D3 #A3
33 -> (U8,P.114/PD0) D2 #A2
34 -> (U8,P.86/PD15) D1 #A1
35 -> (U8,P.85/PD14) D0 #A0
36 GND
37 NC (EXT_ENC_B)
38 NC (EXT_ENC_A)
39 NC (EXT_ENC_PRESS)
40 VCC_3.3V

Click here to see the pinout from internal connector U3

¹⁾

See the chitusystems webpage, https://chitusystems.com/product/tft-touch-screen/ which shows a picture of the SSD1963 display controller

²⁾

As of 17.08.2022, found here: https://github.com/MarlinFirmware/Marlin/issues/14655