4 layers33.2 × 33.2 mm
Pendant
picafe/pendant
A pendant built from two PCBs: a 8×8 bicolor LED matrix module (red, orange, green) and controller board with battery charging, USB-C power, 5 V boost, and motion sensing.
46 parts
4 layers33.2 × 33.2 mm
Matrix
picafe/pendantA pendant built from two PCBs: a 8×8 bicolor LED matrix module (red, orange, green) and controller board with battery charging, USB-C power, 5 V boost, and motion sensing.
- Size
- 33.2 × 33.2 mm
- Copper layers
- 4
- Thickness
- 1.6 mm
- Parts
- 12
- Nets
- 32
- Pads
- 76
- Tracks, vias
- 147, 15
- Pours
- 3
- Routed
- Yes
- KiCad
- KiCad 9.0 (file 20241229)
- Created
- 20 Jun 2026
- Updated
- 21 Jul 2026
Overview
Matrix is an open-source printed circuit board by picafe, from the picafe/pendant repository on GitHub. It is a 4-layer board of 33.2 × 33.2 mm with 12 parts on 32 nets, routed with 147 tracks and 15 vias.
It is built around the HT16K33A-28SSOP and 1N4148WS. Its parts include 3 resistors, 2 diodes, 2 connectors, 1 capacitor and 1 IC. It belongs with the lEDs and displays boards of this library.
Main components
2
HT16K33A-28SSOP
SSOP-28-40℃~+85℃ 1/16 16 segments 16×8 bit 1mA 1uA 4.5V~5.5V Built-in oscillator、Integrated key function I²C SSOP-28 LED Drivers ROHSHoltek SemiconLCD Drivers
1N4148WS
SOD-3231.25V@150mA 100V 150mA 1uA@75V 200mW 2A 4ns Independent SOD-323 Switching Diodes ROHSJiangsu Changjing Electronics Technology (CJ)Switching Diodes
README
README.mdBicolor LED Pendant
A pendant built from two PCBs: a 8×8 bicolor LED matrix module (red, orange, green) and controller board with battery charging, USB-C power, 5 V boost, and motion sensing.
Why I made this
I had already been working on a 32×8 bicolor matrix module and wanted to try the Pendant YSWS before the deadline. An example on the pendant website inspired me to make a bicolor version with an orange fire-style pattern. Fitting the full matrix and controller on one 2/4 layer board was not the most possible, so my design splits into a display PCB and a pendant controller, which are connected with 2.54mm pitch pin headers (likely just male machine pin headers soldered on both sides, since they have a larger spacing to accomodate for the inductor). There is also an accelerometer to have potential particle motion simulation.
Photos
3D model
Schematic
Controller
Matrix
PCB layouts
Controller board
Matrix module
Connections
All signals between the two boards are carried on PCB-mounted 2.54 mm pin headers. No off-board wiring is required beyond a LiPo cell on the controller.
Bill of materials
Prices are per-unit LCSC values; standard connector values are estimated.
Controller PCB
| Ref | Qty | Value | LCSC | Unit | Extended |
|---|---|---|---|---|---|
| U3 | 1 | STM32C071G8U6 | C44521811 | $1.67 | $1.67 |
| U4 | 1 | TPS61022 | C915088 | $1.32 | $1.32 |
| U5 | 1 | LIS2DW12TR | C189624 | $1.25 | $1.25 |
| U1 | 1 | XC6206P332MR | C5446 | $0.102 | $0.10 |
| U6 | 1 | TP4056-42-ESOP8 | C16581 | $0.19 | $0.19 |
| L1 | 1 | FXL0530-1R0-M | C475517 | $0.17 | $0.17 |
| Q1, Q2, Q3 | 3 | BSS138W | C28646265 | $0.025 | $0.08 |
| D1 | 1 | BAT54CW | C22392482 | $0.035 | $0.04 |
| D2 | 1 | Red LED | C2286 | $0.009 | $0.01 |
| D3 | 1 | SS34 | C8678 | $0.030 | $0.03 |
| F1 | 1 | SMD1206B150TFT | C269120 | $0.03 | $0.03 |
| S1 | 1 | Tactile button | C720477 | $0.053 | $0.05 |
| J4 | 1 | USB-C receptacle | C18357552 | $0.08 | $0.08 |
| J1 | 1 | JST-SH 4-pin | - | $0.08 (est.) | $0.08 |
| J2, J3 | 2 | 4-pin pin socket | - | $0.05 (est.) | $0.10 |
| J5 | 1 | 2-pin pin socket | - | $0.03 (est.) | $0.03 |
| C9–C13 | 5 | 10 µF | C440198 | $0.069 | $0.35 |
| C1 | 1 | 4.7 µF | C19666 | $0.014 | $0.01 |
| C8 | 1 | 10 µF | C96446 | $0.021 | $0.02 |
| C3, C4, C7 | 3 | 100 nF | C14663 | $0.006 | $0.02 |
| C5 | 1 | 1 µF | C15849 | $0.008 | $0.01 |
| C6 | 1 | 1 µF | C28323 | $0.012 | $0.01 |
| C2 | 1 | 100 nF | C1525 | $0.004 | $0.00 |
| R10–R11, R8–R9 | 4 | 4.7 kΩ | C25900 | $0.004 | $0.02 |
| R4, R5 | 2 | 5.1 kΩ | C25905 | $0.004 | $0.01 |
| R2, R6 | 2 | 100 kΩ | C25741 | $0.004 | $0.01 |
| R1 | 1 | 750 kΩ | C23240 | $0.004 | $0.00 |
| R3 | 1 | 1 kΩ | C11702 | $0.004 | $0.00 |
| R7 | 1 | 10 kΩ | C25804 | $0.004 | $0.00 |
| R12 | 1 | 10 kΩ | C25744 | $0.004 | $0.00 |
| R13 | 1 | 120 Ω | C25079 | $0.004 | $0.00 |
Controller subtotal: $5.71
Matrix PCB
| Ref | Qty | Value | LCSC | Unit | Extended |
|---|---|---|---|---|---|
| U1 | 1 | HT16K33A-28SSOP | C5444738 | $0.50 | $0.50 |
| LED1 | 1 | 8×8 bicolor LED matrix | - | $1.50 (est.) | $1.50 |
| R1–R3 | 3 | 47 kΩ | C25819 | $0.004 | $0.01 |
| C1 | 1 | 100 nF | C14663 | $0.006 | $0.01 |
| D1 | 1 | 1N4148WS | C2128 | $0.012 | $0.01 |
| J1, J2 | 2 | 4-pin pin socket | - | $0.05 (est.) | $0.10 |
Matrix subtotal: $2.13
Total component cost
| Board | Subtotal |
|---|---|
| Controller | $5.71 |
| Matrix | $2.13 |
| Grand total (1× each board) | $7.84 |
Does not include PCB fabrication, shipping, LiPo battery, or assembly fees.
Parts
12| Qty | Value | Footprint | References |
|---|---|---|---|
| 3 | 47kΩ | PCM_JLCPCB:R_0603 | R1, R2, R3 |
| 3 | SolderJumper_2_Open | Jumper:SolderJumper-2_P1.3mm_Open_RoundedPad1.0x1.5mm | JP1, JP2, JP3 |
| 2 | Conn_01x04_Socket | Connector_PinSocket_2.54mm:PinSocket_1x04_P2.54mm_Vertical | J1, J2 |
| 1 | 100nF | PCM_JLCPCB:C_0603 | C1 |
| 1 | 1N4148WS | PCM_JLCPCB:D_SOD-323 | D1 |
| 1 | DISP_SEGMENT_8X8_BICOLOR_ROWCATHODEMI2A883XX | custom:SEGMENT_BICOL_BL-M12A883XX | LED1 |
| 1 | HT16K33A-28SSOP | Package_SO:SSOP-28_3.9x9.9mm_P0.635mm | U1 |
Questions
How big is the Matrix PCB?
It measures 33.2 × 33.2 mm and has 4 copper layers, 1.6 mm thick.
What parts does the Matrix use?
12 parts, built around the HT16K33A-28SSOP and 1N4148WS. The full list of its parts is on this page, with links to each part's symbol and footprint where PCBKit's library has them.
Where can I download the Matrix KiCad files?
From the picafe/pendant repository on GitHub, at the commit this page was made from: the board is matrix/matrix.kicad_pcb and its schematic controller/pendant.kicad_sch. PCBKit opens the board in the browser, with nothing to install.
Can I use the Matrix design in my own project?
Its repository states no licence, so its author keeps all rights: ask picafe before reusing the design.
More from picafe/pendant
1Similar boards
- 2 layers136.8 × 33.5 mm
Bicolour matrix
picafe/bicolor-matrix
A 32x8 bicolor LED matrix module based on the Holtek HT16K33A LED driver.
52 parts - 4 layers132.4 × 33.4 mm
Bicolour matrix
picafe/bicolor-matrix-v2
A 32x8 bicolor LED matrix module composed of 4 8x8 matrices based on the Holtek HT16K33A I2C LED driver. V1 paired it with a stacked adapter (RP2040 Zero + DS3231 module); V2 redesigns the matrix routing and puts an…
51 parts - 2 layers
- 2 layers134 × 88 mm
Tulipcc
shorepine/tulipcc
The Tulip Creative Computer and AMYboard - portable Python synthesizers
103 parts978 - 8 layers100.2 × 55 mm
Jetson nano baseboard
antmicro/jetson-nano-baseboard
Antmicro's open hardware baseboard for the NVIDIA Jetson Nano, TX2 NX and Xavier NX
391 parts548Apache-2.0 - 4 layers94.4 × 72.8 mm
RP2040 base
Twisted-Fields/rp2040-motor-controller
A dual channel brushless motor controller based on the RP2040 microcontroller, designed in Kicad.
325 parts419 - 2 layers135.9 × 89.5 mm
Left
TeXitoi/keyseebee
KeySeeBee is a split ergo keyboard. It is only 2 PCB (so the name) with (almost) only SMD components on it. It's only a keyboard, no LED, no display, nothing more than keys and USB.
61 parts348MIT - 4 layers70 × 54 mm
