User Manual
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It is necessary to configure the SpoolScale before use. There are two different ways to do this; with a USB-Serial adapter, or with an i2C keypad. The i2C keypad is the suggested way of configuring the SpoolScale as it is much more convenient and unlocks more functionality.
Configuration with Keypad
Note: Configuration with keypad only works if the SpoolScale is in GPIO mode.
First, connect the keypad to your SpoolScale using the included RJ12 cable. It is recommended to connect the keypad to the SpoolScale while it is powered off, but plugging the keypad into an already-powered-on SpoolScale should work. If it doesn't, simply power cycle the SpoolScale to correct any issues. It is also important to note that the keypad inputs are ignored if the SpoolScale has been disabled by the printer's GPIO, so you can only configure settings when the SpoolScale is on and in idle mode (when the screen is displaying the weight).
To prevent accidental changing of settings, the first keypress of any settings change has to be held down for 2 seconds. After that, keys can be pressed at any speed, but keep in mind the keypad can only process hitting a single key at a time, so make sure to fully release one key before pressing the next.
The following keys can be pressed to modify a setting:
A-D: Pressing and holding one of these 4 keys will load a saved spool weight. When successfully loaded, the screen will display the letter (as best it can, being a 7-segment display) followed by the weight for a second before returning to normal operation.
#: Pressing and holding the pound (aka "hashtag") button on the keypad enters the spool weight setting mode. The screen will display "____" when successfully entered. You can then use the numbers to enter a spool weight, between 0 and 999 grams. Pressing # again will save that as the current spool weight, or pressing one of the A-D keys will save that number as the respective preset. Saving the weight as a preset does not automatically call that preset, you would have to do that by pressing and holding the key.
*: Pressing and holding the asterisk (aka "star") button on the keypad will enter calibration mode. Follow the on-screen prompts and reference the section of the User Manual about Calibration for more information. When using the keypad, pressing any key will advance to the next step of the calibration.
Configuration with USB
To configure over USB, connect any USB-UART adapter of your choice to the SpoolScale's two GPIO screw terminals while the system is powered down. The one closer to the +5 volt input is the RX pin, so it should be connected to the TX pin of the adapter. The other GPIO is the TX pin, so it should be connected to the RX pin of the adapter. You will also have to connect +5 volts and ground from the USB-UART adapter to the SpoolScale's power and ground screw terminals. Nothing else should be connected to the power and GPIO pins while using a USB-UART adapter, so the configuration of your SpoolScale through this method does mean essentially uninstalling it from your 3D printer to make changes.
Before plugging in the USB-UART adapter, slide the mode selector switch on the back of the SpoolScale to the center position. Then, plus in the adapter and connect to it with the serial terminal of your choice at a baud rate of 9600. Once the SpoolScale receives power, you should see the display on the front read out "Uart" to show it is in UART configuration mode.
There are only 4 UART commands supported for configuration. All commands are case-sensitive:
s XXX sets the empty spool offset weight to XXX grams. Positive values between 0 and 999 grams are accepted. Sending this command immediately saves the new value to EEPROM.
c will start the calibration routine, spitting out commands over UART. When prompted, you will have to send subsequent "c" characters to move on to the next step.
w will report the current weight of the remaining filament, in grams.
h will list out help and information.
You can simply remove power from the SpoolScale when you are done configuring it this way, and then re-wire it to return to normal operation.
Configuration with i2C
If running in i2C mode, it is possible to configure the SpoolScale directly with the i2C connection. See the section on Interacting via i2C for more information.
