Nfdb

USB-C Daughterboard for Norbaforce

For all models of the Norbaforce (also works with the Norbauer Data Pad).

Features USB-C port, ESD protection, over voltage protection, CC1 & CC2 resistors to work with USB-C to C cables.

Finishes on Norbaforces vary greatly. They were designed for USB mini cables so it is possible a USB-C cable end may not fit depending a finish. In those cases a very light filing of the USB opening using a hobby file can enlarge the opening just enough for the cable.

(Note there is one PCB that can have a connector for Realforce 1 OR Realforce 2 models)

Version No Keyboard Connector

Version Realforce R1

• Models: 86U, 87U, 88U, 91U
• PCB Connector: LCSC: C265068
• Cable: EH to EH (2.5mm pitch), 4 pin, SAME direction, Length 6cm (shielding cable 13cm)

Version Realforce R2

• Models: R2 TKL, R2 RGB TKL, RT1 (numpad)
• PCB Connector: LCSC: C69152
• Cable: PH to PH (2.0mm pitch), 5 pin, REVERSED Direction, Length 11cm

Manufacturing

Details

* Manufacturing files are set up for JLCPCB. * Thickness does not matter suggest standard 1.6mm * "Remove Order Number" option choose "Specify Location" (uses "JLCJLC" on silkscreen for order # position) * Assemble top side * Choose assembly file version (No connector: need to solder then yourself, RF1 or RF2 as indicated above in renders) * Manual part adjustments from KiCad Outputs (already handled in manufacturing files)

Part	Adjustment
USB-C Connector	Down 5.06mm
JST EH Connector	Up 3.75mm
JST PH Connector	Rotate 90°, Down 4mm

BOM

LCSC part #	Description	Value	Package	Amount
C261942	Fuse		0805	1
C7519	ESD		SOT23-6	1
C212411	Resistor	5.1K	0805	2
C597300	Capacitor	4.7nF	0805	1
C165948	Connector (USB)		TH	1
C265068	Connector (EH)	4 pin	TH	1
C69152	Connector (PH)	5 pin	TH	1

Note if the capacitor or resistors are out of stock they can be replaced with 0805 sized component with similar specs.

EH -> PH Cable Experiments

Details

Tested a sample cable using manufactured PH crimped wires in an EH cable housing end (LCSC: C161661) to make a PH to EH cable without manually crimping. Worked without issues after 350 connection cycles. Potential could use R2 daughterboard connector can be used for both R2 and R1 boards.

Notes

R2 NFDB and the Realforce RT1 (Topre numpad)

The R2 NFDB is compatible with the Topre Realforce RT1 numpad (released in 2024), which shares a similar footprint to the predecessor Realforce 23u.

Photos

Norbaforce MKI (cutout is USB shape no issues with fit) Norbaforce MKIII (unfinished no fit issues) Norbaforce MKII RF2 Norbaforce MKII (slight internal filing was needed) Norbauer Data Pad and the R1 NFDB Norbauer Data Pad with RT1 pcb - use R2 NFDB

Special thanks

• Nekotato: for requesting, testing & driving this project
• Techbeezin: for test fitting the vast collection of Norbaforces
• Cipulot: answering various questions regarding Realforce and general electrical questions/advice
• d0nk: for pre-testing the R2 OEM cabling/pinout on RT1