2 layers341.7 × 195.5 mm
VesselV3
Hy-5/VesselV3
Custom "Vessel" Keyboard - PCB + 3D Case Model + Firmware + Keycaps vector
382 partsMIT
2 layers45 × 20 mm
Lpc1756 totp
itzandroidtab/totp8Hardware 2FA TOTP authenticator
- Size
- 45 × 20 mm
- Copper layers
- 2
- Thickness
- 1.6 mm
- Parts
- 52
- Nets
- 93
- Pads
- 217
- Tracks, vias
- 415, 70
- Pours
- 2
- Routed
- Yes
- KiCad
- KiCad 7 (file 20221018)
- Created
- 14 Jan 2024
- Updated
- 10 Jun 2026
Overview
Lpc1756 totp is an open-source printed circuit board by itzandroidtab, from the itzandroidtab/totp repository on GitHub. It is a 2-layer board of 45 × 20 mm with 52 parts on 93 nets, routed with 415 tracks and 70 vias.
It is built around the AMS1117-3.3, PTS810SJK250SMTRLFS and ABM3B-12.000MHZ-B2-T, with the ABS07-32.768KHZ-T, BC856A,215-JSM and IP4234CZ6,125(ES) among its other parts. Its parts include 14 resistors, 10 capacitors, 4 ICs, 3 diodes and 3 switches. It belongs with the NXP (LPC, Kinetis, i.MX RT) boards of this library.
Main components
7
AMS1117-3.3
SOT-223-40℃~+125℃ 0.003%Vout 1 1.1V@(800mA) 15V 1A 3.3V 5mA 72dB@(120Hz) Fixed Over Current Protection、Short Circuit Protection、Thermal shutdown Positive SOT-223 Voltage Regulators - Linear, Low Drop Out (LDO) Regulators ROHSAdvanced Monolithic SystemsVoltage Regulators - Linear, Low Drop Out (LDO) Regulators
PTS810SJK250SMTRLFS
SMD-4P,4.2x3.2mm-40℃~+85℃ 16V 2.5mm 2.6N 3.2mm 4.2mm 50mA J-Lead Round Button SPST Surface Mount,Vertical SMD-4P,4.2x3.2mm Tactile Switches ROHSC&KTactile Switches
ABM3B-12.000MHZ-B2-T
SMD5032-4P-20℃~+70℃ 12MHz 18pF 70Ω Crystal Oscillator ±20ppm ±50ppm SMD5032-4P Crystals ROHSAbraconCrystals
ABS07-32.768KHZ-T
SMD3215-2P-40℃~+85℃ 12.5pF 32.768kHz 70kΩ Crystal Oscillator ±20ppm SMD3215-2P Crystals ROHSAbraconCrystals
BC856A,215-JSM
SOT-231 PNP 100MHz 100mA 1nA 250 250mW 5V 650mV 65V PNP SOT-23 Bipolar (BJT) ROHSJSMSEMIBipolar (BJT)
IP4234CZ6,125(ES)
SOT-23-6LSOT-23-6L ESD and Surge Protection (TVS/ESD) ROHSElecSuperUncategorised
MS621FE-FL11E
UncategorisedSeiko Instruments
README
readme.mdHardware TOTP token
Open source hardware TOTP token. Currently targets the LPC1756, LPC1758 and LPC1759 (with a small change it should also run on the LPC1754).
Features
- keys never leave the token after setup
- support for 6 and 8 digit tokens
- enter button types 6/8 digit token using HID keyboard (any device that supports HID keyboards should work)
- supports up to 32 profiles
- rechargable RTC battery
- USB mode to add/delete profiles using a CSV file (supports base32, hex and hex string)
- support to change the RTC calibration values in the settings
- support for setting the time + timezone (currently only GMT)
- 60 seconds screen timeout
- support for different intervals (supports 1 - 180 seconds)
Images
Images can be found in the project logs at hackaday
TODO
- encrypt profiles
- add support for more than 32 profiles (needs a rework if more profiles are required. The profiles are copied to ram and there is not enough for more at the moment. If we leave them in flash we can store a lot more)
- rework the calibration and time settings screens
Compiling
TOTP uses klib. This repo can be cloned in the klib project folder. See build.yml for more info on compiling this project.
Extra
Is intended to be used with USB dfu bootloader. To build without bootloader support remove the + 8k and - 8k from line 20 in the linkerscript.ld of this project.
The LPC1756 does not have enough ram to hold a full framebuffer (240 * 135 * 2 = 64'800 bytes). To work around this issue, we use 2 smaller framebuffers we alternate between. While one framebuffer is being transferred to the screen using DMA we fill the other.
To make it easier (for me) the whole screen is written to this smaller framebuffer. The pixels that do not fit the framebuffer are thrown away. This does waste CPU cycles but is not limiting the framerate. Filling a full frame with pixels takes around 6 milliseconds. Writing a full frame of framebuffers to the display takes around 11 milliseconds. This limits the maximum framerate to ≈ 85FPS. To get a consistant frame rate there is a limit of 60FPS.
The main screen takes the longest to draw. This is caused by the amount of pixels of the circle it needs to draw. The circle is generated on compile time to work around that the LPC175x family does not have a FPU. These generated pixels use 8640 bytes of flash.
Parts
52| Qty | Value | Footprint | References |
|---|---|---|---|
| 6 | , , , , , | ||
| 4 | 100nF | Capacitor_SMD:C_0603_1608Metric_Pad1.08x0.95mm_HandSolder | C7, C8, C9, C10 |
| 4 | 18pF | Capacitor_SMD:C_0603_1608Metric_Pad1.08x0.95mm_HandSolder | C3, C4, C5, C6 |
| 4 | 1k | Resistor_SMD:R_0603_1608Metric | R9, R11, R13, R14 |
| 3 | PTS810SJK250SMTRLFS | _SamacSys:PTS810SJG250SMTRLFS | S1, S2, S3 |
| 2 | 10uF | Capacitor_SMD:C_0603_1608Metric_Pad1.08x0.95mm_HandSolder | C1, C2 |
| 2 | 300 | Resistor_SMD:R_0603_1608Metric | R3, R6 |
| 2 | 33 | Resistor_SMD:R_0603_1608Metric | R1, R2 |
| 1 | 1.5K | Resistor_SMD:R_0603_1608Metric | R8 |
| 1 | 1.8K | Resistor_SMD:R_0603_1608Metric_Pad0.98x0.95mm_HandSolder | R12 |
| 1 | 1000 | Resistor_SMD:R_0603_1608Metric | R5 |
| 1 | 10K | Resistor_SMD:R_0603_1608Metric_Pad0.98x0.95mm_HandSolder | R10 |
| 1 | 1K | Resistor_SMD:R_0603_1608Metric | R7 |
| 1 | 750 | Resistor_SMD:R_0603_1608Metric | R4 |
| 1 | ABM3B-12.000MHZ-B2-T | _SamacSys:XTAL_ABM3B-12.000MHZ-B2-T | Y2 |
| 1 | ABS07-32.768KHZ-T | _SamacSys:ABS0716632768KHZT | Y1 |
| 1 | AMS1117-3.3 | Package_TO_SOT_SMD:SOT-223-3_TabPin2 | U2 |
| 1 | BC856A,215 | _SamacSys:SOT95P230X110-3N | Q1 |
| 1 | D_Schottky | Diode_SMD:D_SOD-523 | D3 |
| 1 | IP4234CZ6,125 | _SamacSys:SOP95P275X110-6N | D1 |
| 1 | LED | LED_SMD:LED_0805_2012Metric | D2 |
| 1 | LOGO | _SamacSys:koon_logo | G*** |
| 1 | LPC1756FBD80,551 | _SamacSys:QFP50P1400X1400X160-80N | IC1 |
| 1 | MC32603 | _SamacSys:MC32603 | J1 |
| 1 | MS621FE-FL11E | _itz:MS621FE-FL11E | BT1 |
| 1 | RN2425_TE85L,F_ | _SamacSys:RN2425TE85LF | Q2 |
| 1 | TC2050 | Connector:Tag-Connect_TC2050-IDC-FP_2x05_P1.27mm_Vertical | U3 |
| 1 | st7735_mini_lcd | _itz:ST7735 | U1 |
The 47 most common of 52 parts.
Questions
How big is the Lpc1756 totp PCB?
It measures 45 × 20 mm and has 2 copper layers, 1.6 mm thick.
What parts does the Lpc1756 totp use?
52 parts, built around the AMS1117-3.3, PTS810SJK250SMTRLFS, ABM3B-12.000MHZ-B2-T and ABS07-32.768KHZ-T. 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 Lpc1756 totp KiCad files?
From the itzandroidtab/totp repository on GitHub, at the commit this page was made from: the board is hardware/kicad/lpc1756_totp.kicad_pcb and its schematic hardware/kicad/cpu.kicad_sch. PCBKit opens the board in the browser, with nothing to install.
Can I use the Lpc1756 totp design in my own project?
Its repository states no licence, so its author keeps all rights: ask itzandroidtab before reusing the design.
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