Differences

This shows you the differences between two versions of the page.

--- lasercutter2 [2025-05-31 16:12] – simon
+++ lasercutter2 [2025-06-21 20:29] (current) – [Log] simon
@@ Line 202: / Line 202: @@
 ===== Access Control =====
-The access control unit will be external to the laser cutter chassis and connected by a cable:
+The access control is external to the laser cutter chassis and connected by a CAT5 cable:
-  * GND
+| Orange       | Power 5V              |
-  * 5V supply (from laser cutter, always on)
+| White-Orange | Power ground.         |
-  * Enable power-up (open drain)
+| Green        | Relay signal          |
-  * Current clamp A
+| White-Green  | Relay ground          |
-  * Current clamp B
+| Blue         | Current transformer   |
-  * (additional pins may be required for better active/idle detection)
+| White-Blue   | Current transformer   |
+| Brown        | Laser activity signal |
-===== Monitoring =====
+| White-Brown  | Laser activity ground |
-An external unit will contain an ESP8266 and LCD. It will connect to the main chassis by cable:
+The tool controller has it's own 5V PSU which is alway-on when the laser cutter is plugged-in.
-  * GND
+An additional relay is fitted in the laser cutter chassis. The relay's coil is energised by the tool controller's 5V power supply, and it's output is in series with the laser cutter's contactor control input. This means that we don't need to route 240V mains into the tool controller enclosure.
-  * 5V supply (from laser cutter, always on or switched)
-  * One wire bus for DS18B20 temperature sensors
-  * I2C SDA
-  * I2C SCL
-  * Laser enable pin
-  * Laser power level pin
-  * Laser powered-up signal?
-  * Laser cutter in use signal?
-The monitoring device will:
+A laser activity monitor is fitted to give the tool controller visibility of actual laser firing. The 5V control input on the high voltage laser PSU is connected, via an optocoupler, to a Raspberry Pi Pico. The Pico tracks the current state of the PSU input  and the accumulated time in microseconds. This data is [[https://github.com/edinburghhacklab/laser-timer-i2c|presented to the tool controller via I2C]].
-  * Log laser tube time
+{{:0:25-05-31_15-31-16_3152.jpg?direct&200|}}
-  * Log temperatures (ambient, coolant out/return, bed, exhaust)
+{{:0:25-05-31 15-35-41 3153.jpg?direct&200|}}
-  * Detect cutting sessions and report the most recent on the LCD
+{{:0:25-05-31 15-35-45 3154.jpg?direct&200|}}
-  * Potentially, log fume/particulate levels
+{{:0:25-05-31 15-39-22 3155.jpg?direct&200|}}
+{{::laser-activity-monitor-connections.png?direct&200|}}
+Since the photos were taken the optocoupler 5V input is now taken from the laser cutter's controller board USB port. This is avoid false //active// readings during shutdown, where the laser PSU's 5V rail stays active for 8 seconds after losing power.
+Note that the tool controller will also detect an active state based on **attempted** firing of the laser. For example, if the lid is opened during a job the laser will be disabled but the time will still be counted.
+The software is still in an inconsistent state. The laser activity time is displayed on the LCD, and it is used to detect activity, but the values reported on the tool status page will assume 100% duty cycle at 0.5 second resolution.
+Additional monitoring could be added in future:
+  * Temperatures (ambient, coolant out/return, bed, exhaust)
+  * Air-flow
+  * Fume/particulate levels
 ===== Log =====
@@ Line 303: / Line 308: @@
 -02-22:
-  * Guide laser is not working (Simon)
+  * Guide laser is not working
 -04-26:
-  * External extraction fan moved from active RCD plug to passive RCD socket (Simon)
+  * External extraction fan moved from active RCD plug to passive RCD socket
 -05-31:
-  * Guide laser ground wire was broken in two places, repaired and aligned (Simon)
+  * Active time monitoring connected to the tool controller
+  * Guide laser ground wire was broken in two places, repaired and aligned
+-06-13:
+   * Guide laser doesn't work in certain positions, the wires need replacing
 {{tag>equipment}}