4 layers132.5 × 82 mm
Wandfernsprecher
hanebefl/wandfernsprecher-hw
GSM conversion for a old German Wandfernsprecher telephone
93 parts6
2 layers57.8 × 25.9 mm
Entry
Atefan/Diploma1Diploma work for
- Size
- 57.8 × 25.9 mm
- Copper layers
- 2
- Thickness
- 1.6 mm
- Parts
- 24
- Nets
- 56
- Pads
- 97
- Tracks, vias
- 93, 0
- Routed
- Yes
- KiCad
- KiCad 8.0 (file 20240108)
- Created
- 3 Oct 2024
- Updated
- 6 Jul 2026
Overview
Entry is an open-source printed circuit board by Atefan, from the Atefan/Diploma repository on GitHub. It is a 2-layer board of 57.8 × 25.9 mm with 24 parts on 56 nets, routed with 93 tracks and 0 vias.
It is built around the MBRS1100T3G-FS and SC0918. Its parts include 2 inductors, 1 diode and 1 transistor.
Main components
2README
README.mdEntropy — Hardware True Random Number Generator
ELSYS Sofia diploma project.
The problem
Computers are deterministic — they can only produce pseudo-random numbers, which is not good enough for real cryptographic or security-sensitive use (secure communications, bank transfers, key generation, etc.). This project builds a true hardware entropy source and feeds it directly into the Linux kernel's entropy pool, so real applications get genuine randomness instead of PRNG output.
How it works
- Analog front-end — a custom white-noise generation circuit (charge-pump
voltage multiplier + PWM stage, op-amp) produces physical noise, sampled
through the ADC. Schematic and PCB in
Pico_PCB/. - Firmware (
Entropy device/) — runs on a Raspberry Pi Pico (RP2040, dual-core). One core samples the ADC and drives the PWM/noise circuit; the noise is buffered in a circular queue and streamed to the host over USB. Built with the Pico SDK + CMake. - Linux kernel driver (
driver/) — a USB driver (usb_entropymodule) that reads the incoming stream and exposes it as/dev/entropy, feeding it straight into the kernel's entropy pool vialinux/random.h. - GUI (
GUI/) — an SDL2-based Windows app that visualizes the live entropy output in real time. - Validation (
testing/) — randomness was verified with the NIST Statistical Test Suite (STS 2.1.2, vendored here).
Parts
24| Qty | Value | Footprint | References |
|---|---|---|---|
| 6 | .1uF | Capacitor_SMD:C_1206_3216Metric_Pad1.33x1.80mm_HandSolder | C_GND1, C_GND2, C_oscilato1, C_oscilato2, C_supply1, C1 |
| 3 | 220 | Resistor_SMD:R_1206_3216Metric | R_LED_B1, R_LED_G1, R_LED_R1 |
| 3 | MBRS1100T3G | MBRS1100T3G:SMB_403A-03_ONS | CR1, CR2, CR3 |
| 2 | L | Inductor_SMD:L_Coilcraft_LPS4414 | L1, L3 |
| 1 | 10k | Resistor_SMD:R_1206_3216Metric | Rg1 |
| 1 | 120 | Resistor_SMD:R_1206_3216Metric | Rf2 |
| 1 | 15K | Resistor_SMD:R_1206_3216Metric | Rf3 |
| 1 | 1M | Resistor_SMD:R_1206_3216Metric | Rsch1 |
| 1 | 1k | Resistor_SMD:R_1206_3216Metric | Rf4 |
| 1 | 2n3904 | Package_TO_SOT_SMD:SOT-23 | Q2 |
| 1 | 680k | Resistor_SMD:R_1206_3216Metric | Rf1 |
| 1 | MCP6L91RT-EMS | op_amp_MCP6291-E/MS:MSOP8_MC_MCH | 8_pin_op_amp1 |
| 1 | MP008253 | MP008253:MP008253 | LED1 |
| 1 | SC0918 | Pico W:MODULE_SC0918 | PicoW1 |
Similar boards
- 2 layers90 × 76 mm
KAPTON HEATERV2
AslanLauzon/KAPTON-CONNECTOR
This system uses a 24V, 14.6A Kapton trace heater to regulate the pressure inside a nitrous oxide oxidizer tank, particularly in colder environments where vapor pressure drops below optimal levels.
33 parts - 2 layers100 × 81.3 mm
- 2 layers72 × 67 mm
EV Design Challenge
land-barrett/EV_Design_Challenge
KiCAD files of 2026 TAMU SAE Formula EV electrical design challenge
78 parts - 4 layers100 × 90 mm
Sensor dmf board
esyywar/Digital-Microfluidic-Control
A complete digital microfluidic system including PCB hardware, arduino microcontroller firmware and real-time control software.
58 parts2 - 2 layers90 × 90 mm
KAPTON HEATERV2
Queens-Rocket-Engineering-Team/prop-ecad
All PCB and electrical schematics for the propulsion team
22 parts - 2 layers87.9 × 98.7 mm
Bitdoglab smd
BitDogLab/BitDogLab
Open-source educational hardware for embedded systems, programming, electronics, and physical computing.
138 parts203 - 2 layers47.2 × 55.5 mm
Tinta l2
c0de111/tinta
Battery-powered e-paper sign: room signage, sensor graphs, home automation, or anything over Wi-Fi. Wakes by real-time clock, NFC tap, or button. Raspberry Pi Pico W firmware, custom PCB, and 3D-printed case included.
60 parts39Apache-2.0
Questions
How big is the Entry PCB?
It measures 57.8 × 25.9 mm and has 2 copper layers, 1.6 mm thick.
What parts does the Entry use?
24 parts, built around the MBRS1100T3G-FS and SC0918. 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 Entry KiCad files?
From the Atefan/Diploma repository on GitHub, at the commit this page was made from: the board is Pico_PCB/Entry/Entry.kicad_pcb and its schematic Pico_PCB/Entry/Entry.kicad_sch. PCBKit opens the board in the browser, with nothing to install.
Can I use the Entry design in my own project?
Its repository states no licence, so its author keeps all rights: ask Atefan before reusing the design.