This is a collection of PCBs that I created, with everything from the schematic to Gerber/Drill files for manufacture.
- stm32f103cx: Cortex-M3 STM32F103Cx (e.g., STM32F103C8T6) based core board. Includes breakout for the TQFP48 IC, crystal provisions, an MP2307-based input SMPS IC circuit that can generate 3.3V, a ULN2003AD output driver and a 74HC4050 input level shifter. The idea is that you only populate what you need and just leave everything off that you don't. Created as a 100x100mm so that it fits Seeed Studio or other low-cost prototyping manufacturers.
- stm32f103rx: Cortex-M3 STM32F103Rx (e.g., STM32F103RBT6) based core board. Includes breakout for the TQFP64 IC, crystal provisions, an MP2307-based input SMPS IC circuit that can generate 3.3V, a ULN2003AD output driver and a 74HC4050 input level shifter. The idea is that you only populate what you need and just leave everything off that you don't. Created as a 100x100mm so that it fits Seeed Studio or other low-cost prototyping manufacturers.
- stm32f030kx: Cortex-M0 STM32F030Kx (e.g., STM32F030K6T6) based core board. Includes breakout for the TQFP32 IC, crystal provisions, an MP2307-based input SMPS IC circuit that can generate 3.3V, a ULN2003AD output driver and a 74HC4050 input level shifter. The idea is that you only populate what you need and just leave everything off that you don't. Created as a 100x100mm so that it fits Seeed Studio or other low-cost prototyping manufacturers.
- softoff: A soft-off circuit using CD4011 for extremely low off-power consumption and an added ATtiny13 microcontroller to allow for features such as auto-off after a specific time. A simulation of the circuit is available here. It basically is an RS flipflop that drives a P-Fet and avoids invalid states (i.e., even when nR and nS are asserted at the same time, the behavior of the circuit is well-defined).
CC-0.