Control Panel for K40 laser cutters/engravers
What it CAN do:
- Monitor input/output coolant flow and temperature (using "YF-B4"-type sensors and thermistors)
- Monitor lids opening (using two microswitches)
- Monitor for fire (using an LM393 IR flame sensor module)
- Control a 3 channels relays board for:
- CO2 laser activation (the main switch/interlock on an vanilla K40, not the "fire" button)
- Air-assist activation
- Alarm activation
- Control 12V lights
- Control 5V laser diodes
- Control a motorized bed (based on this design, but it should work with other ones as long as the stepper can be controeled using a DRV8825 driver)
- Expose sensors/state data through an API
- Retrieve the current state of the machine and move the laser head through UART if you're using a FluidNC controller board (WIP)
Don't expect an ultra smooth experience, the ESP32 being a bit underpowered for a screen of that size the user interface can be a bit laggy sometimes (eg. during screen transitions or scrolling). It should still be fully usable though.
For the control panel:
- 1x NodeMCU-32 (38 pins)
- 1x ILI9488 3.95" LCD screen
- 1x DRV8825 stepper driver
- 1x L7805CV 5V regulator
- 2x IRLML6244 N-channel MOSFETs
- 2x 1N4007 diodes
- 7x 10kΩ 1/4W R1206 SMD resistors
- 3x 1kΩ 1/4W R1206 SMD resistors
- 2x 220Ω 1/4W R1206 SMD resistors
- 1x 0.1uF electrolytic capacitors
- 1x 100uF electrolytic capacitors
- 3x 0.1uF ceramic capacitors
- 1x 2P PCB terminal blocks (5mm pitch)
- some 2.54mm pin headers / XH connectors / jumpers
Other things you may need:
- 1x motorized bed with a NEMA17 stepper and a limit switch
- 1x 3 channel relay board
- 1x air compressor for air assist
- 2x YF-B4 flow sensor with a thermistor (preferably one with a 50kΩ resistance at 25°C and B=3950K)
- 1x LM393 IR flame sensor module
- 2x micro switches
- 1x (or 2x depending on your needs) 5V laser diodes
- 1x 12V LED light (for the enclosure)
- 1x 12V blinking light (for the alarm)
- 1x FluidNC controller board
Make sure you have Python 3.x installed on your system, then run:
# Install/update Platform.io
pip install --upgrade platformio
# Build the firmware
pio buildThen flash your ESP32 using the upload target.
OTA updates are available using the OTA target. In order to use it copy the .env.dist file to .env and change the values of OTA_UPLOAD_URL, OTA_LOGIN and OTA_PASSWORD in it accordingly to the settings of your control panel.
You can also take a .bin file and upload it through the ElegantOTA interface available at http://<YOUR_PANEL_IP>/update.
Production files can be found in the gerber folder of this repository.
The design fits on a 100x100mm PCB, so you should be able to get it built for really cheap by online suppliers.
Coming soon™
GET http://<YOUR_PANEL_IP>/api/info
{
"firmware": {
"version": "9da28a82",
"build_date": "Apr 30 2023 18:31:43"
},
"system": {
"chip": {
"model": "ESP32-D0WDQ5",
"revision": 1
},
"heap": {
"free": 80268,
"total": 257148
},
"cpu": {
"freq_mhz": 240,
"load_percent": {
"core_0": 0,
"core_1": 0.100000001
}
},
"tasks": {
"display_update": {
"state": "ready",
"priority": 1,
"high_water_mark": 1348
},
"bed_update": {
"state": "blocked",
"priority": 0,
"high_water_mark": 1044
},
"state_update": {
"state": "ready",
"priority": 0,
"high_water_mark": 600
},
"grbl_rx": {
"state": "blocked",
"priority": 1,
"high_water_mark": 1508
},
"grbl_tx": {
"state": "blocked",
"priority": 1,
"high_water_mark": 1992
},
"settings_save": {
"state": "blocked",
"priority": 0,
"high_water_mark": 472
},
"cpu_monitor": {
"state": "blocked",
"priority": 0,
"high_water_mark": 340
},
"async_tcp": {
"state": "running",
"priority": 3,
"high_water_mark": 15064
}
}
}
}GET http://<YOUR_PANEL_IP>/api/sensors
{
"sensors": {
"cooling": {
"flow": {
"input": 5.619999886,
"output": 5.60124556
},
"temp": {
"input": 18.89999962,
"output": 21.3
}
},
"lids": {
"front": "opened",
"back": "closed"
},
"flame_sensor": {
"triggered": false
}
}
}GET http://<YOUR_PANEL_IP>/api/alerts
{
"alerts": {
"cooling": false,
"lids": true,
"flame_sensor": false
}
}GET http://<YOUR_PANEL_IP>/api/relays
{
"relays": {
"interlock": false,
"air_assist": true,
"cooling": true,
"alarm": false,
"lights": true,
"beam_preview": true
}
}GET http://<YOUR_PANEL_IP>/api/grbl
{
"state": 1,
"w_pos": {
"x": 0,
"y": 0,
"z": 0
},
"m_pos": {
"x": 0,
"y": 0,
"z": 0
},
"wco": {
"x": 0,
"y": 0,
"z": 0
},
"buffer": {
"planned_buffer_available_blocks": 100,
"rx_buffer_available_bytes": 20
},
"feed": {
"rate": 0,
"spindle_speed": 0
},
"line_number": 0,
"active_pins": {
"x": false,
"y": false,
"z": false,
"p": false,
"d": false,
"h": false,
"r": false,
"s": false
}
}