Intro

• This repository includes the schematics and PCB design of a double-layer STM32 development Board.
• The code name "JNBG" is in the honour of my group who helped and encouraged me in this project.
• The design is done on KiCAD 6.0

Components List:

Component	Description	Quantity	Was Used
STM32f030f4p6	ARM® Cortex®-M0 48MHz FLASH 2.4V ~ 3.6V 32-Bit TSSOP-20 ST Microelectronics	1	Yes
AMS1117- 3V3	3V3 LDO Linear Voltage Regulator SOT-223-3	1	Yes
CH340C	IC Transceiver USB 2.0 2Mbps SOP-16	1	Yes
USBLC6-2SC6	ESD Protection TVS Unidirectional Dual Array SOT23-6	1	Yes
SMAJ5.0A	Unidirectional TVS 5.0V DO-214AC	1	Not Available
Crystal Oscillator	Crystal Oscillator 32MHz 3225	1	Yes
LEDs	Green and Red LEDs 0805	1* Green, 1*Red	Yes
Ferrite Bead	100Ω @ 100MHz 2.5A 1 100mΩ 0805	1	Yes
22uF Capacitor	SMD 22uF 0805	2	Replaced with 1205 Counterpart
4.7uF Capacitor	SMD 4.7uF 0603	2	Yes
1uF Capacitor	SMD 1uF 0603	2	Yes
100n Capacitor	SMD 100nF 0603	1	Yes
47nF Capacitor	SMD 47nF 0805	1	Yes
10nF Capacitor	SMD 10nF 0603	1	Yes
10pF Capacitor	SMD 10pF 0603	2	Yes
10k ohm Resistor	SMD 10k 0603	3	Yes
1k ohm Resistor

- In this circuit, the AMS1117 is used to regulate 5V from USB to 3.3V, with a unidirectional TVS to protect against surges. - The board is provided with a USB-B Micro port, providing power and communication to the controller. - The differential pair is connected to au nidirectional Dual TVS for ESD protection. Finally, the differentials are connected to a USB-to-TTL interface: CH340C. This variant was chosen because it can operate without an external crystal. - It is worth mentioning that until this time, this module has not been tested yet. ### a- Crystal Oscillator - For calculting the value of capacitors, the following equation is used: Capacitor Value = ( Load Capaitance of Crystal [10pf] + Stray Capacitance of PCB [maximum estimate = 10pF] ) / 2 - Source: Phill's Lab Course on KiCAD 6.0 ### b- Power: - According to the datasheet of STM32f03x, it is recommeded to connect VDD pin to the shown capacitances. - For more stable ADC performance, a ferrite bead is added to the VDDA connections. ### c- Interfacing: - GPIO pins are connected to headers for easier interface, while taking speical signals into considerations (i.e. I2C pair) - A SPDT switch is added to control the BOOT0 pin, and a RST button is added. - For experimental purposes, extra pair of headers are added to power the STM32 directly, bypassing the regulator.