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eddyem/stm32samples
Code samples and ready projects based on bare-metal STM32

Code samples and ready projects based on bare-metal STM32
Chrono is an open-source printed circuit board by eddyem, from the eddyem/stm32samples repository on GitHub. It is a 2-layer board of 97.5 × 59.5 mm with 90 parts on 60 nets, routed with 564 tracks and 25 vias.
It is built around the L80-R, LM2576-5.0WU and LM1117-3.3, with the USBLC6-2SC6, AO3407 and B340A among its other parts. Its parts include 24 resistors, 17 capacitors, 13 connectors, 11 diodes and 7 ICs. It belongs with the sensors and measurement and computers and single-board computers boards and the STM32 boards of this library.
The stm32samples repository is a collection of low-level, bare-metal code examples and complete
projects for various STM32 microcontroller series (F0, F1, F3, F4, G0). It uses CMSIS header files
from modm-io/cmsis-header-stm32 for register definitions.
-flto optimisationsdeprecated/This repository is a valuable resource for learning low‑level STM32 programming without vendor libraries. It covers practical applications:
For the latest updates, check the repository on GitHub.
This repository is provided under the GNU General Public License v3 or later. Full text of the GPLv3 is available at https://www.gnu.org/licenses/gpl-3.0.html.
| Qty | Value | Footprint | References |
|---|---|---|---|
| 11 | 0.1 | Capacitor_SMD:C_0603_1608Metric_Pad1.05x0.95mm_HandSolder | C3, C5, C6, C8, C9, C11, C12, C14, C15, C16, C17 |
| 7 | 1N5819 | Diode_SMD:D_SOD-323_HandSoldering | D2, D3, D4, D5, D6, D10, D11 |
| 5 | 10k | Resistor_SMD:R_0603_1608Metric_Pad1.05x0.95mm_HandSolder | R1, R5, R8, R19, R23 |
| 5 | 1k | Resistor_SMD:R_0603_1608Metric_Pad1.05x0.95mm_HandSolder | R6, R10, R11, R12, R20 |
| 4 | Jumper | Connector_PinHeader_2.54mm:PinHeader_1x02_P2.54mm_Vertical | JP1, JP2, JP3, JP4 |
| 3 | 220 | Resistor_SMD:R_0603_1608Metric_Pad1.05x0.95mm_HandSolder | R15, R16, R17 |
| 2 | 100 | Resistor_SMD:R_0603_1608Metric_Pad1.05x0.95mm_HandSolder | R13, R21 |
| 2 | 10u | Capacitor_SMD:C_1206_3216Metric_Pad1.42x1.75mm_HandSolder | C4, C10 |
| 2 | 12 | Capacitor_SMD:C_0603_1608Metric_Pad1.05x0.95mm_HandSolder | C1, C2 |
| 2 | 22 | Resistor_SMD:R_0603_1608Metric_Pad1.05x0.95mm_HandSolder | R3, R4 |
| 2 | 47k | Resistor_SMD:R_0603_1608Metric_Pad1.05x0.95mm_HandSolder | R14, R24 |
| 2 | 510 | Resistor_SMD:R_0603_1608Metric_Pad1.05x0.95mm_HandSolder | R7, R18 |
| 1 | 100k | Resistor_SMD:R_0603_1608Metric_Pad1.05x0.95mm_HandSolder | R22 |
| 1 | 100u | Inductor_SMD:L_12x12mm_H4.5mm | L1 |
| 1 | 100u | Capacitor_THT:CP_Radial_D8.0mm_P3.50mm | C7 |
| 1 | 1k5 | Resistor_SMD:R_0603_1608Metric_Pad1.05x0.95mm_HandSolder | R9 |
| 1 | 2k2 | Resistor_SMD:R_0603_1608Metric_Pad1.05x0.95mm_HandSolder | R2 |
| 1 | 47u | Capacitor_Tantalum_SMD:CP_EIA-3216-18_Kemet-A_Pad1.58x1.35mm_HandSolder | C13 |
| 1 | 4N25 | Package_DIP:DIP-6_W7.62mm | U3 |
| 1 | 8MHz | Crystal:Crystal_HC49-U_Vertical | Y1 |
| 1 | AO3407 | Package_TO_SOT_SMD:SOT-23_Handsoldering | Q2 |
| 1 | B340A | Diode_SMD:D_SMA_Handsoldering | D7 |
| 1 | Bluetooth | Connector_PinSocket_2.54mm:PinSocket_1x06_P2.54mm_Vertical | J11 |
| 1 | Buzzer 3v3 | Buzzer_Beeper:Buzzer_12x9.5RM7.6 | BZ1 |
| 1 | Ext_trig0 | TerminalBlock_Phoenix:TerminalBlock_Phoenix_MKDS-1,5-2-5.08_1x02_P5.08mm_Horizontal | J5 |
| 1 | Ext_trig1 | TerminalBlock_Phoenix:TerminalBlock_Phoenix_MKDS-1,5-2-5.08_1x02_P5.08mm_Horizontal | J4 |
| 1 | Ext_trig2 | TerminalBlock_Phoenix:TerminalBlock_Phoenix_MKDS-1,5-2-5.08_1x02_P5.08mm_Horizontal | J7 |
| 1 | GPS_ext | Connector_JST:JST_PH_B5B-PH-K_1x05_P2.00mm_Vertical | J2 |
| 1 | I2C1 | Connector_PinSocket_2.54mm:PinSocket_1x04_P2.54mm_Vertical | J9 |
| 1 | IRML2502 | Package_TO_SOT_SMD:SOT-23_Handsoldering | Q4 |
| 1 | L80-R | chrono:L80-R | U5 |
| 1 | LED0 | LED_THT:LED_D5.0mm | D8 |
| 1 | LED1 | LED_THT:LED_D5.0mm | D9 |
| 1 | LIDAR | Connector_PinSocket_2.54mm:PinSocket_1x04_P2.54mm_Vertical | J10 |
| 1 | LM1117-3.3 | TO_SOT_Packages_SMD:SOT-223 | U4 |
| 1 | LM2576-5.0 | TO_SOT_Packages_THT:TO-220-5_P3.4x3.7mm_StaggerEven_Lead3.8mm_Vertical | U2 |
| 1 | MM3Z7V5 | Diode_SMD:D_0805_2012Metric_Pad1.15x1.40mm_HandSolder | D1 |
| 1 | MMBTA42 | Package_TO_SOT_SMD:SOT-23_Handsoldering | Q1 |
| 1 | PC817 | Package_DIP:DIP-4_W7.62mm | U7 |
| 1 | PPS | Connector_PinSocket_2.54mm:PinSocket_1x02_P2.54mm_Vertical | J3 |
| 1 | Power 12V | TerminalBlock_Phoenix:TerminalBlock_Phoenix_MKDS-1,5-2-5.08_1x02_P5.08mm_Horizontal | J1 |
| 1 | SI2305 | Package_TO_SOT_SMD:SOT-23_Handsoldering | Q3 |
| 1 | SPI | Connector_PinSocket_2.54mm:PinSocket_1x05_P2.54mm_Vertical | J8 |
| 1 | STM32F103C6Tx | Package_QFP:LQFP-48_7x7mm_P0.5mm | U6 |
| 1 | SWD | Connector_PinSocket_2.54mm:PinSocket_1x04_P2.54mm_Vertical | J12 |
| 1 | USBLC6-2SC6 | TO_SOT_Packages_SMD:SOT-23-6_Handsoldering | U1 |
| 1 | USB_B | Connectors_USB:USB_B_OST_USB-B1HSxx_Horizontal | P1 |
| 1 | USB_B_Mini | Connector_USB:USB_Mini-B_Lumberg_2486_01_Horizontal | J6 |
The 83 most common of 90 parts.
It measures 97.5 × 59.5 mm and has 2 copper layers, 1.6 mm thick.
90 parts, built around the L80-R, LM2576-5.0WU, LM1117-3.3 and USBLC6-2SC6. 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.
From the eddyem/stm32samples repository on GitHub, at the commit this page was made from: the board is F1:F103/deprecated/chronometer_v2/kicad/chrono.kicad_pcb. PCBKit opens the board in the browser, with nothing to install.
Its repository states no licence, so its author keeps all rights: ask eddyem before reusing the design.

eddyem/stm32samples
Code samples and ready projects based on bare-metal STM32







eddyem/stm32samples
Code samples and ready projects based on bare-metal STM32




eddyem/stm32samples
Code samples and ready projects based on bare-metal STM32


eddyem/ARMsingleboard
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PennyLekas/Nixie-Clock
v1 is broken and required some bodge wires to work. I have not updated the schematic and PCB to correct my mistakes. It also has some deficencies in the dimming circuit resulint in a quiet, but audible whine.

