BluePill VA.1

illustrate

Modified from baobaoa's project, original project link https://oshwhub.com/baobaoa/bluepill , modified based on https://oshwhub.com/spadger/bluepill

Changes

1. Modify the interface to Type-B to facilitate soldering. A larger space is reserved on this side to facilitate replacement with Type-B pads of other sizes.
2. Reduce the width of the borders on both sides of the pin header to reduce the occupied space.
3. Move the crystal oscillator to the right, away from the MCU, making it easier to desolder the MCU in the future.
4. Move the 32K crystal oscillator upward so that the crystal oscillator lies horizontally and centered.

Welding instructions

1. USB Type-B is difficult to solder with soldering iron and soldering iron. It is recommended to use solder paste to heat air soldering. Apply a small amount and then heat it.
2. Before applying tin paste, you need to preheat the soldering pad to 80°C - 100°C with a hot air gun. At this time, the applied tin paste will spread and will not easily gather and cause accumulation.
3. Except for USB Type-B, all other components can be soldered with soldering wire and soldering iron.
4. For soldering, it is recommended to use standard 183℃ lead-containing 6337 solder wire, otherwise the GND copper-clad pad will not easily absorb tin, resulting in a weak solder.
5. The 4.7K resistor can be replaced by a 10K resistor, but the two LEDs will be darker if 10K is used.