[Q] pinout and button ?

[DrumClock]

Hi, I have a few questions:

1) What is the "USER" button for? 2) can the points on the PCB marked TP3, TP4, and TP5 be used as additional I / O pins?

Thank you.

[mks-viva]

Hi!

1. User button you can define it as kill_pin
2. TP3: PB10，TP4: PA15，TP5: PD11，you can define it to other function

[DrumClock]

HI, thank you very much. Is it possible to define TP3-TP5 pins as PWM for servo control use?

[mks-viva]

Hi! PB10/PA15 is PWM pin

[DrumClock]

Thanks @mks-viva , I have one more question.

If I use the TMC 2209 UART-Mode driver, will I be able to use the I / O pins on the EXP 3 connector for other functions (eg 2x servo, Neopixel LED, etc.)?

[mks-viva]

No, because it has been used in TMC2209 uart

[DrumClock]

Hi, I also noticed it while studying the schematic.

If I compare it, for example, with the board ROBIN_PRO which usesSERIAL_TX_PIN = SERIAL_RX_PIN .... PD5

Query:

What if I remove resistors R90 to R95 and define them same SERIAL_RX_PIN = SERIAL_TX_PIN .... PC14

Then I could use EXP3 without limiting the UART mode.

Thank you

[mks-viva]

Yes, it can be done. Currently STM32 supports 1 IO for UART mode setting

[DrumClock]

Hi @mks-viva OK, I'm waiting for the delivery of the MKS Rumba32 board. I'll run a test and give info on how it works.

Edit the pins_RUMBA32_MKS file.

//
  // Software serial
  //
  #define X_SERIAL_TX_PIN                   PC14        // desoldering resistor R90 on board
  #define X_SERIAL_RX_PIN                   PC14

  #define Y_SERIAL_TX_PIN                   PE4         // desoldering resistor R91 on board
  #define Y_SERIAL_RX_PIN                   PE4

  #define Z_SERIAL_TX_PIN                   PE0         // desoldering resistor R92 on board
  #define Z_SERIAL_RX_PIN                   PE0

  #define E0_SERIAL_TX_PIN                  PC13        // desoldering resistor R93 on board
  #define E0_SERIAL_RX_PIN                  PC13

  #define E1_SERIAL_TX_PIN                  PD5         // desoldering resistor R94 on board
  #define E1_SERIAL_RX_PIN                  PD5

  #define E2_SERIAL_TX_PIN                  PD1         // desoldering resistor R95 on board
  #define E2_SERIAL_RX_PIN                  PD1

  // Reduce baud rate to improve software serial reliability
  #define TMC_BAUD_RATE                    19200

#endif

//
// define pin EXP3
//

#define SERVO0_PIN                          PD15        // SWITCHING EXTRUDER E0,E1
#define SERVO1_PIN                          PD14        // PWM 1
#define POWER_LOSS_PIN                      PA3         // Pin to detect power loss
#define NEOPIXEL_PIN                        PA4         // LED driving pin  
#define E0_AUTO_FAN_PIN                     PD13        // FAN HOTEND 0 - external MOSFET chanel
#define E1_AUTO_FAN_PIN                     PD12        // FAN HOTEND 1 - external MOSFET chanel

/**   
* Reserved for I2C and UART 1
*
*  ENC_1 to 4                               PB8         // I2C - SCL 
*  ENC_1 to 4                               PB9         // IC2 - SDA 
*  AUX-1 Use UART 1 - TX                    PA9         // #define SERIAL_PORT_2 1
*  AUX-1 Use UART 1 - RX                    PA10        // #define SERIAL_PORT_2 1  
*
*/

//
// Z Probe (when not Z_MIN_PIN)
//
#ifndef Z_MIN_PROBE_PIN
  #define Z_MIN_PROBE_PIN                   PD9
#endif

//
// Runout Probe (when not Y_MAX_PIN)
//
#ifndef Y_MAX_PIN
  #define FIL_RUNOUT1_PIN                   PD8
#endif

[mks-viva]

But you need test it. So, i will close this issues temporarily.