3D Printer (RepRap) Monitor - Part 3 - Operation

The two indicator LEDs provide feedback in regards to the operational status of the RepRap Monitor.

The gas sensor requires a warmup period.   When the monitor is first powered up, or reset, it will first flash a series of fast red / green LED, then alternating red / green LED flashes each second of the warmup period, and finally, somewhat faster alternating red / green LED flashes each second of the gas sensor check.

When the monitor is running normally the green LED will be on and solid.   If the monitor is running in standby the green LED will be flashing three times at 100ms every second.

If the monitor has detected an error the green LED will be extinguished and the red LED will flash for 200ms from 1 to 4 times every second with the frequency indicating the nature of the problem encountered:

• 1 time = Gas threshold exceeded
• 2 times = Gas sensor error
• 3 times = Temperature threshold exceeded
• 4 times = Temp sensor error

Note that if the printer has been shut down the alarm buzzer will sound continuously.

If the monitor needs to indicate a warning state then the red LED will flash at 100ms either two or four times every second with two indicating a gas warning and four indicating a temperature warning.   In either case the green LED will still be lit.  During a warning situation the alarm buzzer will sound with pulses every second, two in the case of a gas warning, and four in the case of a temperature warning.

The gas and temperature levels for errors and warnings are coded as constants within the sketch that drives the RepRap Monitor.  It is the responsibility of the user to set those constants as they vary for every environment!   The source code for the monitor is available here.

Note that the serial port is accessible on the PCB and can be used to monitor status in detail.   Power is also made available which allows connection of a bluetooth serial adapter.

Software for the monitor is available on GitHub.

More in Part IV