3D Printer
Bed Leveling
| GCode | Description |
|---|---|
| M851 Z0 | Set Z-probe offset to 0. |
| M500 | Save all configurable settings to EEPROM. |
| M501 | Load all saved settings from EEPROM. |
| M503 | Print all runtime-configurable settings to the host console. |
| G28 | Auto home. |
| G1 F60 Z0 | Move to Z0. |
| M211 S0 | Unlock software endstops to enable movement below Z0. |
| M109 S190 | Set nozzle temperature to 220 °C. |
| G1 F60 Z-0.2 | Move extruder to Z-0.2. Adjust the value in the previous step until you can just barely move a piece of paper placed between the nozzle and print bed. Subtract another 0.1 from this value. This will be your new Z-probe offset value. |
| M851 Z-2.2 | Set Z-probe offset to -2.2. This value should be whatever you measured in the previous step. |
| M211 S0 | Lock software endstops to prevent movement below Z0. |
| M500 | Save all configurable settings to EEPROM. |
| M501 | Load all saved settings from EEPROM. |
| M503 | Print all runtime-configurable settings to the host console. |
| G28 | Auto home. |
| G1 F60 Z0 | Move to Z0 to confirm. |
| M109 S0 | Set nozzle temperature to 0 °C. |
Start and End GCode
start.gcode
; Set Heat Bed temperature
M140 S{material_bed_temperature_layer_0}
; Set Extruder temperature
M104 S{material_print_temperature_layer_0}
; Home all axes
G28
; Level bed
G29
; Reset Extruder
G92 E0
; Move to start position
G1 X0.1 Y20 Z0.3 F5000.0
; Wait for Heat Bed temperature
M190 S{material_bed_temperature_layer_0}
; Wait for Extruder temperature
M109 S{material_print_temperature_layer_0}
; Draw the first line
G1 X5.5 Y200.0 Z0.3 F1500.0 E15
; Move to side a little
G1 X5.9 Y200.0 Z0.3 F5000.0
; Draw the second line
G1 X5.9 Y20 Z0.3 F1500.0 E30
; Reset Extruder
G92 E0
; Move Z Axis up little to prevent scratching of Heat Bed
G1 Z2.0 F3000
end.gcode
; Relative positioning
G91
; Retract
G1 E-2 F2700
; Retract and raise Z
G1 E-2 Z0.2 F2400
; Wipe out
G1 X5 Y5 F3000
; Raise Z more
G1 Z10
; Absolute positionning
G90
; Present
G1 X0 Y{machine_depth}
; Turn-off fan
M106 S0
; Turn-off hotend
M104 S0
; Turn-off bed
M140 S0
; Disable all steppers but Z
M84 X Y E
LED Light Relay
Raspberry Pi 4B Rev 1.2.
The relay module is connected to physical pins 4 (5V), 6 (GND), and 36 (GPIO 16).
The version of wiringpi in the Raspberry Pi OS repos is out of date and doesn't support the Pi 4B, so we have to install a newer version.
cd /tmp
wget https://project-downloads.drogon.net/wiringpi-latest.deb
sudo dpkg -i wiringpi-latest.deb
Then we can figure out how our Pi's physical pins map to wiringpi's pin numbers:
$ gpio readall
+-----+-----+---------+------+---+---Pi 4B--+---+------+---------+-----+-----+
| BCM | wPi | Name | Mode | V | Physical | V | Mode | Name | wPi | BCM |
+-----+-----+---------+------+---+----++----+---+------+---------+-----+-----+
| | | 3.3v | | | 1 || 2 | | | 5v | | |
| 2 | 8 | SDA.1 | IN | 1 | 3 || 4 | | | 5v | | |
| 3 | 9 | SCL.1 | IN | 1 | 5 || 6 | | | 0v | | |
| 4 | 7 | GPIO. 7 | IN | 1 | 7 || 8 | 1 | IN | TxD | 15 | 14 |
| | | 0v | | | 9 || 10 | 1 | IN | RxD | 16 | 15 |
| 17 | 0 | GPIO. 0 | IN | 0 | 11 || 12 | 0 | IN | GPIO. 1 | 1 | 18 |
| 27 | 2 | GPIO. 2 | IN | 0 | 13 || 14 | | | 0v | | |
| 22 | 3 | GPIO. 3 | IN | 0 | 15 || 16 | 0 | IN | GPIO. 4 | 4 | 23 |
| | | 3.3v | | | 17 || 18 | 0 | IN | GPIO. 5 | 5 | 24 |
| 10 | 12 | MOSI | IN | 0 | 19 || 20 | | | 0v | | |
| 9 | 13 | MISO | IN | 0 | 21 || 22 | 0 | IN | GPIO. 6 | 6 | 25 |
| 11 | 14 | SCLK | IN | 0 | 23 || 24 | 1 | IN | CE0 | 10 | 8 |
| | | 0v | | | 25 || 26 | 1 | IN | CE1 | 11 | 7 |
| 0 | 30 | SDA.0 | IN | 1 | 27 || 28 | 1 | IN | SCL.0 | 31 | 1 |
| 5 | 21 | GPIO.21 | IN | 1 | 29 || 30 | | | 0v | | |
| 6 | 22 | GPIO.22 | IN | 1 | 31 || 32 | 0 | IN | GPIO.26 | 26 | 12 |
| 13 | 23 | GPIO.23 | IN | 0 | 33 || 34 | | | 0v | | |
| 19 | 24 | GPIO.24 | IN | 0 | 35 || 36 | 0 | IN | GPIO.27 | 27 | 16 |
| 26 | 25 | GPIO.25 | IN | 0 | 37 || 38 | 0 | IN | GPIO.28 | 28 | 20 |
| | | 0v | | | 39 || 40 | 0 | IN | GPIO.29 | 29 | 21 |
+-----+-----+---------+------+---+----++----+---+------+---------+-----+-----+
| BCM | wPi | Name | Mode | V | Physical | V | Mode | Name | wPi | BCM |
+-----+-----+---------+------+---+---Pi 4B--+---+------+---------+-----+-----+
Here, we can see that physical pin 36 maps to wPi 27 (BCM 16 == GPIO 16). Why the fuck is this so needlessly confusing?
Set the pin to output:
gpio mode 27 out
Turn the relay on:
gpio write 27 1
Turn the relay off:
gpio write 27 0