Centauri Carbon Emulator

Purpose

I am developing a monitor for my Elegoo Centauri Carbon (CC) printer using a Cheap Yellow Display (CYD) programmed in MicroPython (both of these items are new to me). I quickly realized that in order to test my device's code, I would need to keep my printer running and producing status messages. This seemed problematic, especially when I found that an error in my code could cause the CC to lock up hard and require a power-down and rest before starting up again.

So instead I created this "emulator" (using the term quite loosely) for the desktop that can record the status messages produced during a print by the real printer. Then they can be played back in a convenient and repeatble fashion while I tested my device.

Background

The Centauri Carbon acts a Websocket server - this is how your desktop slicer sends files to and retrieves status updates from it. The messages conform to the "standard" (another loose term here) detailed at:

https://github.com/cbd-tech/SDCP-Smart-Device-Control-Protocol-V3.0.0

(Note the examples shown in the documentation are for a resin printer, which explains why Elegoo varied from it. I expect other manufacturers to do the same.)

The files

cc_recorder.py

This script is a Websocket client that will connect to a live CC printer and create a JSON-format log file from the messages it receives. At startup, it will broadcast a query to all devices on the local network and then connect to the first printer that responds. This is needed even if the printer's IP address is known in advance because the response contain parameters needed in the following step.

Once a websocket connection to the printer is created, a single message is sent to it requesting "status" updates. The program loops, receiving the messages until it is stopped by pressing ENTER at the terminal/command line.

python3 cc_recorder.py <logfile> <ip-addr>

logfile is where the messages are stored. Default = "cc-log.json".

ip-addr is an optional specific printer's IP address to connect with. Useful when more thanone printer (or a printer and cc_player) is active on the network.

Update:

cc_recorder has been updated to replace the original TimeStamp field (Unix epoch number of seconds since 1970-01-01) with the relative number of seconds since the previous message. This allows for easier manual editing of files to reduce the number (and time) of emulated records.

cc_player.py

This script is a Websocket server that a monitor program can connect to without bothering a real printer. It responds to broadcast requests, using the desktop's IP address and machine name in place of the normal CC ones. When it gets a request for status messages, it will send them to the client until it disconnects or the program is terminated (press ENTER at the terminal).

The messages are read from a file created by cc_recorder.py. Some machine-specific fields are replaced such as the "TimeStamp" field, which gets the current time. Before the message is sent, this program delays for the number of seconds difference between the previous and current messages. This more closely emulates a real printer's operation than would just flooding the client with a slew of messages.

When the end of the file is reached, after a short delay, the program starts over again at the beginning of the file.

python3 cc_player.py <logfile> <speed>

logfile contains messages to be sent. Default = "cc-log.json".

speed is a rate multiplier for the delay between messages. 0.5 is used for half-speed; 1.0 for normal speed (default) and 2.0 would be double-speed.

Update:

cc_player has been updated to handle the "record relative" TimeStamp fields produced by cc_recorder. (It will also handle the older "full timestamp" files as well.)