STM32H7 pin connections for 3D printer main board
In order for Marlin firmware to work properly on my imaginary main board I'm building. Turns out there is a file in a Marlin GitHub repository that has pre set pins for certain popular main boards that use H7 as their brain. One of those is a BTT Kraken.
If you go to: Marlin/src/pins/stm32h7/pins_BTT_KRAKEN_V1_0.h, there are all the defined pins. It can be changed, however for the first time I don't think I have expertise to do it for this first board I'm making.
As for that file, I understand it up to a certain point. So I asked ChatGPT to explain it completely. For example:
define X_STEP_PIN PC14
define X_DIR_PIN PC13
define X_ENABLE_PIN PE6
define X_CS_PIN PD6
Those are for x axis motor control.
define TMC_SPI_MOSI PC8
define TMC_SPI_MISO PC7
define TMC_SPI_SCK PC6
Those are for controlling all the motor drivers. I still don't understand the protocol how those drivers are controller, so I need to explore that more.
define X_DIAG_PIN PC15
define Y_DIAG_PIN PF0
define Z_DIAG_PIN PF1
Those are for diagnostic I guess... ChatGPT says it's for sensorless homing. I have to admit I don't know that also works.
define TEMP_0_PIN PB1
define TEMP_1_PIN PC5
define TEMP_2_PIN PC4
define TEMP_3_PIN PA7
define TEMP_BED_PIN PB0
Those are for thermistor readings, so we can read temperatures. There are 5 of them, however my Ender uses only 2, so I might incorporate 3 into the board.
define HEATER_BED_PIN PF5
define HEATER_0_PIN PF6
define HEATER_1_PIN PF7
define HEATER_2_PIN PF9
define HEATER_3_PIN PF8
There are heater pins for controlling the heaters.
define FAN0_PIN PA0
define FAN1_PIN PA1
define FAN2_PIN PA2
define FAN3_PIN PA3
define FAN4_PIN PA4
define FAN5_PIN PA5
define FAN6_PIN PA6
define FAN7_PIN PE8
Fan pins, not even funny how many are those.
define SERVO0_PIN PE9
define Z_MIN_PROBE_PIN PG1
Those are for BlTouch. I would like to add BlTouch to my printer, then I don't need the Z limit switch.
define PS_ON_PIN PD10
I don't know what's going on with that last pin. AI says it's for controlling the main power supply with a relay. I don't know how would it work. Maybe if the PSU has multiple outputs, so that board can stay powered, and turn off the other output.
