2 layers32.8 × 52.5 mm
Scrapped
matarga/simple-devboard
Mk1 is the internal name of this project. I am using this as a way to learn about PCB design and embedded systems and make a "final" out of it.
52 parts
2 layers27.8 × 33.6 mm
Simple devboard
matarga/simple-devboardMk1 is the internal name of this project. I am using this as a way to learn about PCB design and embedded systems and make a "final" out of it. The "final" that I have made is a simple, low-cost, ESP32-S3 development board. I originally added tons of sensors and complexity but shaved them off to make the project more attainable.
- Size
- 27.8 × 33.6 mm
- Copper layers
- 2
- Thickness
- 1.6 mm
- Parts
- 28
- Nets
- 57
- Pads
- 196
- Tracks, vias
- 232, 18
- Routed
- Yes
- KiCad
- KiCad 10.0 (file 20260206)
- Created
- 17 May 2026
- Updated
- 6 Jul 2026
Overview
Simple devboard is an open-source printed circuit board by matarga, from the matarga/simple-devboard repository on GitHub. It is a 2-layer board of 27.8 × 33.6 mm with 28 parts on 57 nets, routed with 232 tracks and 18 vias.
It is built around the CH340X, TLV75533PDRV and MMBT3904. Its parts include 12 resistors, 6 capacitors, 3 ICs, 2 transistors and 2 connectors. It belongs with the microcontroller boards and sensors and measurement boards and the ESP32 boards of this library.
Main components
3
CH340X
MSOP-10-20℃~+70℃ 2Mbps 3.3V、5V USB 2.0 USB to serial、USB to Parallel MSOP-10 USB Converters ROHSWCH (Nanjing Qinheng Microelectronics)USB Converters
TLV75533PDRV
WSON-6-EP(2x2)-40℃~+125℃@(Tj) 1 238mV@(500mA) 25uA 3.3V 46dB@(100kHz) 5.5V 500mA 71.5uVrms Fixed Over Current Protection、Short Circuit Protection、Thermal shutdown、Enable control、Input under-voltage protection、Output discharge、Built-in soft-start Positive WSON-6-EP(2x2) Voltage Regulators - Linear, Low Drop Out (LDO) Regulators ROHSTexas InstrumentsVoltage Regulators - Linear, Low Drop Out (LDO) Regulators
MMBT3904
SOT-23-55℃~+150℃ 1 NPN 100 100nA 200mA 200mW 300MHz 300mV 40V 6V NPN SOT-23 Bipolar (BJT) ROHSJiangsu Changjing Electronics Technology (CJ)Bipolar (BJT)
README
README.mdMk1
Mk1 is the internal name of this project. I am using this as a way to learn about PCB design and embedded systems and make a "final" out of it. The "final" that I have made is a simple, low-cost, ESP32-S3 development board. I originally added tons of sensors and complexity but shaved them off to make the project more attainable. The board functions similar to most other boards, boasting a USB to Serial converter, a sample IMU sensor for SPI testing, and extra essentials like auto reset circuits and a voltage regulator. The board has gone well but I advise most to not use any of these designs for future projects of their own. If you do, don't be surprised when it blows up in your face.
Horizons reviews please check in the /REVIEWERS folder
Journal logs are in the /documentation folder of this repo
The schematic breakdown goes as follows:
The ESP32-S3
The power rails start with two decoupling capacitors before then merging with reset and boot circuit through pull up resistors
The IMU
The IMU is a simple MPU-9250 following the schematic posted its online datasheet
USB to Serial IC
The USB to Serial IC is a FTDI FT231XQ also following the schematic posted in its datasheet
Auto reset
The auto reset circuit is a set of two 2N3984 transistors that feed into the DTR and RTS pins of the FT231XQ, When a handshake is sent by the flashing device the devboard can enter bootloader states without the need of a button press on the board, though the buttons are still included as a fallback
USB Port
The port is simple with only two 5K1 resistors for USB power negotiation on both sides.
Voltage regulator
The voltage regulator includes one TLV75533PDRV from TI and decoupling capacitors on power ins and outs. And the reset pin is tied to power to keep the chip on while the board has power.
Overall
The PCB is extremely messy.
Parts
28| Qty | Value | Footprint | References |
|---|---|---|---|
| 4 | 12K | Resistor_SMD:R_0201_0603Metric | R1, R2, R4, R7 |
| 3 | 0.1uF | Capacitor_SMD:C_01005_0402Metric | C2, C3, C4 |
| 2 | 10K | Resistor_SMD:R_0201_0603Metric | R5, R6 |
| 2 | 1uF | Capacitor_SMD:C_01005_0402Metric | C5, C6 |
| 2 | 470R | Resistor_SMD:R_0201_0603Metric | R8, R9 |
| 2 | 5K1 | Resistor_SMD:R_0201_0603Metric | R10, R11 |
| 2 | MMBT3904 | Package_TO_SOT_SMD:SOT-23 | Q3, Q4 |
| 2 | SW_Push | Button_Switch_SMD:SW_SPST_B3U-1000P | SW1, SW2 |
| 1 | 200R | Resistor_SMD:R_01005_0402Metric | R12 |
| 1 | 22uF | Capacitor_SMD:C_01005_0402Metric | C1 |
| 1 | 4K1 | Resistor_SMD:R_0201_0603Metric | R3 |
| 1 | CH340X | Package_SO:MSOP-10_3x3mm_P0.5mm | U3 |
| 1 | Conn_01x08_Socket | Connector_JST:JST_EH_S8B-EH_1x08_P2.50mm_Horizontal | J2 |
| 1 | ESP32-S3-WROOM-2 | RF_Module:ESP32-S3-WROOM-2 | U1 |
| 1 | LED | LED_SMD:LED_0201_0603Metric | D1 |
| 1 | TLV75533PDRV | Package_SON:WSON-6-1EP_2x2mm_P0.65mm_EP1x1.6mm | U2 |
| 1 | USB_C_Receptacle_USB2.0_14P | Connector_USB:USB_C_Receptacle_G-Switch_GT-USB-7025 | J1 |
Questions
How big is the Simple devboard PCB?
It measures 27.8 × 33.6 mm and has 2 copper layers, 1.6 mm thick.
What parts does the Simple devboard use?
28 parts, built around the CH340X, TLV75533PDRV and MMBT3904. 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 Simple devboard KiCad files?
From the matarga/simple-devboard repository on GitHub, at the commit this page was made from: the board is CAD/Kicad/Kicad.kicad_pcb and its schematic CAD/Kicad/Kicad.kicad_sch. PCBKit opens the board in the browser, with nothing to install.
Can I use the Simple devboard design in my own project?
Its repository states no licence, so its author keeps all rights: ask matarga before reusing the design.
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Mk1 is the internal name of this project. I am using this as a way to learn about PCB design and embedded systems and make a "final" out of it.
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Scrapped
matarga/simple-devboard
Mk1 is the internal name of this project. I am using this as a way to learn about PCB design and embedded systems and make a "final" out of it.
33 parts
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