Differences

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

--- lasercutter2 [2025-05-31 17:27] – [Access Control] tim
+++ lasercutter2 [2025-06-21 20:29] (current) – [Log] simon
@@ Line 217: / Line 217: @@
 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.
-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 presented to the tool controller via I2C.
+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]].
-===== Monitoring =====
+{{:0:25-05-31_15-31-16_3152.jpg?direct&200|}}
+{{:0:25-05-31 15-35-41 3153.jpg?direct&200|}}
+{{:0:25-05-31 15-35-45 3154.jpg?direct&200|}}
+{{:0:25-05-31 15-39-22 3155.jpg?direct&200|}}
+{{::laser-activity-monitor-connections.png?direct&200|}}
-An external unit will contain an ESP8266 and LCD. It will connect to the main chassis by cable:
+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.
-  * GND
+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.
-  * 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:
+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.
-  * Log laser tube time
+Additional monitoring could be added in future:
-  * Log temperatures (ambient, coolant out/return, bed, exhaust)
-  * Detect cutting sessions and report the most recent on the LCD
+  * Temperatures (ambient, coolant out/return, bed, exhaust)
-  * Potentially, log fume/particulate levels
+  * Air-flow
+  * Fume/particulate levels
 ===== Log =====
@@ Line 317: / Line 314: @@
 -05-31:
-  * Active time monitoring connected to the tool controller (currently overruns on power off)
+  * 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}}