2 layers47.4 × 77.4 mm
2 layers37.4 × 47.4 mm
Switcher
devbotas/pcb-wires-firstA wires-first home automation controllers
- Size
- 37.4 × 47.4 mm
- Copper layers
- 2
- Thickness
- 1.6 mm
- Parts
- 41
- Nets
- 34
- Pads
- 119
- Tracks, vias
- 188, 32
- Pours
- 2
- Routed
- Yes
- KiCad
- KiCad 10.0 (file 20260206)
- Created
- 4 May 2026
- Updated
- 29 Oct 2026
Overview
Switcher is an open-source printed circuit board by devbotas, from the devbotas/pcb-wires-first repository on GitHub, published under the CERN-OHL-S-2.0 licence. It is a 2-layer board of 37.4 × 47.4 mm with 41 parts on 34 nets, routed with 188 tracks and 32 vias.
It is built around the SLG47115V and TPD4E02B04DQAR. Its parts include 7 resistors, 6 capacitors, 5 diodes, 5 connectors and 3 switches. It belongs with the home automation and IoT boards of this library.
Main components
2SLG47115V
STQFN-24(3x3)-40℃~+85℃ 10 2.3V~5.5V GreenPAK OTP STQFN-24(3x3) Programmable Logic Device (CPLDs/FPGAs) ROHSRenesas ElectronicsProgrammable Logic Device (CPLDs/FPGAs)
TPD4E02B04DQAR
USON-10(1x2.5)-40℃~+125℃ 0.33pF 10nA 17W@8/20us 2A@8/20us 3.6V 7.5V 8.8V Bidirectional Four channels IEC 61000-4-2、IEC 61000-4-5、IEC 61000-4-4 TVS USON-10(1x2.5) ESD and Surge Protection (TVS/ESD) ROHSTexas InstrumentsESD And Surge Protection (TVS/ESD)
README
README.mdThe Problem
Wireless IoT sucks.
It's unreliable and breaks all the time. There's not such thing as reliable, maintenance-free, wireless IoT.
If it runs on batteries - that's even worse.
Another problem - central IoT hubs. If those break, lose connection, decides to reboot ar whatever - my smart house immediatelly becomes non-functional.
The Solution
Put the analog wires first! So that light switches continue to operate even if smart features decide to stop working.
The Boards
Gateway
This is a simple carrier board for WizNET W55RP20 development module. It cannot do much by itself - maybe blink some LEDs. Real functionality (and also power) should come from the JST PH headers.
Can be mounted on M or L size Holey board.
Voltage converter
Takes 12-24V input (technically, 5-70V, but these voltages may not be supported on the other modules that this one is supposed to power) and creates 3.3V output so Gateway or other low power modules could be connected through the JST XH connector. Additionally, there are multiple JST VH connectors, which act as a power switch to connect multiple power hungry modules, like the Switcher.
Two can be mounted on a single Holey-S board.
Switcher
Originally meant to control LED lights, but it can switch anything. It has one switchable 12/24V output (should be able to handle 4A). Output can be controlled simultaneously in multiple ways:
- ON wire: shorting this to GND for 100ms will turn the switch on.
- OFF wire: shorting this to GND for 100ms will turn the switch off.
- TGL wire: shorting this to GND for 100ms will toggle the switch.
- I2C directly: software based commands that can turn switch on or off and read the current state.
The idea here that ON/OFF/TGL signals could be wired to the physical wall switches directly, any smart features being entirely optional. So the switch will operate as a dumb-switch.
Renesas HVPAK SLG47115 chip serves both as a high-power switch and an input sanitizer. For example, if faulty hardware shorts ON signal to GND permanently, OFF and TGL signals continue to operate normally.
Two can be mounted on a single Holey-S board.
Holey boards
These are very handy to mount modules listed above, or maybe anything. They have a grid of 3.2mm diameter holes (hence the name) on a 5mm grid. They work perfectly with any M3 mounting hardware and come in the following sizes:
- L - 160x100 mm
- M - 100x80 mm
- S - 80x40 mm
So, one M board can fit exactly two S boards, and one L board can fit exactly 2 M boards. This allows some neat and functional arrangement.
Parts
41| Qty | Value | Footprint | References |
|---|---|---|---|
| 4 | 100nF | Capacitor_SMD:C_0603_1608Metric | C1, C2, C3, C4 |
| 4 | MountingHole | MountingHole:MountingHole_3.2mm_M3_NoCopper | H1, H2, H3, H4 |
| 3 | 2.2k | Resistor_SMD:R_0603_1608Metric | R1, R2, R5 |
| 3 | NetTie_2 | NetTie:NetTie-2_SMD_Pad0.5mm | NT1, NT3, NT4 |
| 3 | SolderJumper_2_Open | Jumper:SolderJumper-2_P1.3mm_Open_RoundedPad1.0x1.5mm | Bit3, PU1, PU2 |
| 2 | 4.7k | Resistor_SMD:R_0603_1608Metric | R6, R7 |
| 2 | 6.7k | Resistor_SMD:R_0603_1608Metric | R3, R4 |
| 2 | I2C | Connector_JST:JST_XH_B4B-XH-A_1x04_P2.50mm_Vertical | J4, J5 |
| 1 | 100 | Resistor_SMD:R_Array_Concave_4x0603 | RN1 |
| 1 | 1000nF | Capacitor_SMD:C_0603_1608Metric | C5 |
| 1 | 3V3 | Diode_SMD:D_0603_1608Metric | D5 |
| 1 | 4.7μF/16V | Capacitor_SMD:C_0603_1608Metric | C6 |
| 1 | BLINK | Diode_SMD:D_0603_1608Metric | D2 |
| 1 | Conn_01x02 | Connector_JST:JST_VH_B2P-VH_1x02_P3.96mm_Vertical | J3 |
| 1 | FAULT | Diode_SMD:D_0603_1608Metric | D1 |
| 1 | GND | TestPoint:TestPoint_Keystone_5019_Miniature | TP1 |
| 1 | HV | Diode_SMD:D_0603_1608Metric | D4 |
| 1 | Input | Connector_Phoenix_MC:PhoenixContact_MCV_1,5_4-G-3.5_1x04_P3.50mm_Vertical | J1 |
| 1 | NetTie_2 | NetTie:NetTie-2_THT_Pad0.3mm | NT2 |
| 1 | OUT | Connector_JST:JST_VH_B2P-VH_1x02_P3.96mm_Vertical | J2 |
| 1 | OUT | Diode_SMD:D_0603_1608Metric | D3 |
| 1 | SLG47115V | Package_DFN_QFN:Renesas_UQFN-20_2x3mm_P0.4mm_SLG47115V | U1 |
| 1 | TPD4E02B04DQA | Package_SON:USON-10_2.5x1.0mm_P0.5mm | U2 |
| 1 | reset | Button_Switch_SMD:SW_SPST_B3U-1000P | SW2 |
| 1 | set | Button_Switch_SMD:SW_SPST_B3U-1000P | SW3 |
| 1 | toggle | Button_Switch_SMD:SW_SPST_B3U-1000P | SW1 |
Questions
How big is the Switcher PCB?
It measures 37.4 × 47.4 mm and has 2 copper layers, 1.6 mm thick.
What parts does the Switcher use?
41 parts, built around the SLG47115V and TPD4E02B04DQAR. 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 Switcher KiCad files?
From the devbotas/pcb-wires-first repository on GitHub, at the commit this page was made from: the board is pcb/switcher/switcher.kicad_pcb and its schematic pcb/gateway/gateway.kicad_sch. PCBKit opens the board in the browser, with nothing to install.
Can I use the Switcher design in my own project?
Its repository publishes it under the CERN-OHL-S-2.0 licence: you may reuse it on that licence's terms (keep the author's notice, and for a copyleft licence share your changes alike).
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