OpenSpool

OpenSpool

Your filament wants to be free

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📖 OpenSpool.io

Checkout the official documentation on https://openspool.io 👈

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Adhere NFC stickers on all your filament. Build an ESP32 OpenSpool reader and place it next to your printer. Touching the filament to the reader will automatically update your Bambu Printer filament settings. Almost as seamlessly as if you were using Bambu filament with an AMS.

🖨️ Protocol

Protocol	Read	Write	Type
OpenSpool	✅	✅	NTAG 215/216
TigerTag	🚧 In progress	🚧 In progress	NTAG 213
Bambu	🚧 In progress	❌	MiFare Classic 1k
OpenTag3D	🚧 In progress	🚧 In progress	NTAG 213/215/216
Creality	🗓️ Planned	🗓️ Planned	MiFare Classic 1k
PrusaRFID	❓	❓	❓
Elegoo	🔍 Researching	🔍 Researching	❓
Anycubic	🔍 Researching	🔍 Researching	❓

🧬 OpenTag3D Protocol

Many 3d printer filament companies are uniting around an open standard called OpenTag3D. It planned to be finalized in early-mid 2025. OpenSpool will support OpenTag formatted tags as soon as it is finalized. See here for more information.

🧬 OpenSpool Protocol

OpenSpool aims to use the simplest possible protocol for RFID tags. All you need is a NTAG215/216

NDEF Record

Example record stored on NFC tag.

type = `application/json`  
payload = 
{
    "protocol": "openspool",
    "version": "1.0",
    "type": "PLA",
    "color_hex": "FFAABB",
    "brand": "Generic",
    "min_temp": "220",
    "max_temp": "240"
}

Web Preview

Spool information can be seen using your phone.

https://openspool.io/tag_info?color_hex=FFAABB&type=PLA&brand=Generic&min_temp=220&max_temp=240&protocol=openspool&version=1.0

🐼 Integrations

Currently, OpenSpool works with Bambu printers over MQTT. Other integrations are planned. Pull Requests welcome

Integration	Supported
Bambu	✅
OctoPrint	🚧 In Progress
Prusa Connect	🗓️ Planned
SpoolMan	🗓️ Planned
Klipper / Moonraker	🗓️ Planned
Anker	❔

Bambu Bambu X1C printers running 1.08.05.00 or newer must enable LAN Mode and Developer Mode for the OpenSpool reader to work. Additional information on bambu’s blog.

All other Bambu Printers and X1C printers running firmware older than 1.08.05.xx do not need to enable Developer Mode.

🔧 Hardware

The OpenSpool schematics will always be free. If you don’t want to source the parts yourself, you can buy a kit on tindie.com.

Bill of Materials

Image	Hardware	Link 1	Link 2
	OpenSpool Mini PCB v3.1 *	Gerber Files
	OpenSpool Mini Enclosure (3D Printed)	MakerWorld
	Wemos D1 Mini s3		AliExpress
	PN532 (Small)	Amazon	AliExpress
	NTAG 215/216 (13.56Mhz NFC Tags >500 bytes)	Amazon
	WS2812B LED	Amazon
	2.54mm Straight Headers	Amazon
	2.54mm Right-Angle Headers	Amazon
	Female-Female jumper wire	Amazon
	1206 10k SMD Resistor *	Amazon
	BSS138 MOSFET *	Amazon

If you are unable to find a Wemos D1 Mini s3, you can still buy an s2, as it is pin compatable. However, be advised the s2 has less memory and may experience occasional disconnects from the printer.

Image	Hardware	Link 1	Link 2
	Wemos D1 Mini S2 (Beware of Fakes!)	Amazon	AliExpress

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It is recommend to assemble OpenSpool using the custom PCB. You can send the Gerber files included in this repository to a PCB fabricator, such as OSH Park.

Without Custom PCB

OpenSpool can be assembled without fabricating the custom PCB. In place of the MOSFET and resistor, you will need the following components:

Image	Hardware	Link 1	Link 2
	3.3v - 5v Logic Level Converter	Amazon
	Mini Breadboard	Amazon

You can use any breadboard or splicing tool to connect the wires, however the linked mini breadboard is recommended as it is small enough to fit inside the enclosure.

🛠️ Assembly

Once you have all of the parts, you can begin assembly.

With Custom PCB

1. Solder the following components onto the PCB:
   1. Two 10k resistors
   2. One BSS138 MOSFET
   3. Four sets of 8 straight headers, into the two pairs of columns on the top of the PCB
   4. One set of 8 right-angle headers into the row of vias just below the OpenSpool logo on the BACK side of the PCB
   5. Three right-angle headers in the top-left corner of the PCB
2. Solder eight right-angle headers onto the top side of the PN532
3. Solder three straight headers onto the LED. Make sure to solder them onto the side with the “Din” pin
4. Place the Wemos D1 onto the headers and solder it on. The top of the Wemos D1 should face up, with the USB-C port facing the bottom of the PCB
5. Use jumper wires to connect both the PN532 and the LED to their respective headers
6. Flip the toggle switches on the PN532 to enable SPI mode (see image below)

Without Custom PCB

If you are not using the custom PCB, you will need to connect the wires to each pin manually. Below is the wiring diagram:

🤖 Firmware

The recommended method to install firmware is by navigating to openspool.io in Chrome/Edge and using the web based programming tool.

Alternatively the firmware can be installed with make commands as shown below.

OSX/Linux

brew install esphome

git clone https://github.com/spuder/OpenSpool
cd OpenSpool/firmware

Press and hold the D0 button while pressing the reset button on the Wemos D1 Mini.
A new USB serial device will appear.

ls /dev/cu*

Upload firmware and restart

USB_ADDRESS=/dev/cu.usbmodemXXXXX make lolin_s2_mini

or

USB_ADDRESS=/dev/cu.usbmodemXXXXX make lolin_s3_mini

🛜 First Time Configuration

A new Wi-Fi network will appear called OpenSpool, join the network, navigate to 192.168.4.1, insert your Wi-Fi credentials and reboot.

You can then navigate to the web interface at openspool-xxxxxx.local or IP address.

🎛️ Configuration

On first boot, you will need to specify your 3d printer IP Address, Serial Number and LAN Access Code.

Do not put your printer into LAN Only Mode, it is not required.

After changing these 3 settings, you will need to reboot the ESP32. Upon successful connection to the 3d printer, you will observe a checkmark next to MQTT in the web interface.

Factory Reset

Press and hold the D0 button for 10 seconds. This will erase Wi-Fi credentials and Bambu access credentials from esp32.

🔧 Troubleshooting

LED is breathing blue

This means the OpenSpool is hosting a wireless access point called ‘OpenSpool’. Connect to it then navigate to 192.168.4.1 to configure Wi-Fi.

LED is solid white

OpenSpool has successfully joined the Wi-Fi network and is ready to scan for RFID tags

NFC Tags aren’t reading reliably

If using the red NP5332 reader (smaller model), it detects tags best on the corners of the antenna.

If using the blue PN532 reader (larger model), it detects tags best directly in the center of the antenna.

Be sure you aren’t using a counterfeit PN532

MQTT Disconnects

The A1/P1 have a limit of 4 mqtt connections. If more than 4 connections are reached clients may be asked to disconnect.

If a client attempts to write invalid data any mqtt topic, the printer will ask the client to disconnect. All ESPhome resources must use state_topic: with a null value to prevent ESPhome from broadcasting on any topic.

TLS Errors

Reach out to the discord for help to verify that the Root Certificate is correct.

Advanced Troubleshooting

Use the MQTTX client to observe the messages that OpenSpool and Bambu Printer are sending.

mqttx sub -t 'device/$SERIAL_NUMBER/report' -u bblp -P $LAN_ACCESS_CODE --mqtt-version 3.1.1 -h $IP_ADDRESS -p 8883 -l mqtts --insecure

🎥 Demo

👥 Contributors

Spencer Owen	raihei	Ember Light	Queen Vinyl Da.i'gyu-Kazotetsu	Tnthr	Phillip Thelen
Sunnyday Technologies	Thijs Triemstra	secprepper

📜 Certifications

OSHWA Certification: US002704

ESPHome Device Listing

🪪 License

Donations

All contributions to the project are welcome. Skills needed:

• Software Development
• Photography
• Videography
• Documentation
• Electrical Design
• Testing/Integration

You can also donate to support research and development costs

https://oshwlab.com/owenspencer/openspool-mini