Spark Logic

Blue Pill polyphonic tone generator connection guide

Blue Pill polyphonic tone generator STM32F103C8T6 Blue Pill wiring guide with power, signal assignments, and bench checks.

STM32F103C8T6 Blue Pill

49 contacts Current package

Spark Logic project archive · The documented blue PCB has two 20-contact headers, SWD and Micro USB. Its PC13 user LED is active low. The USB D+ pull-up varies across production boards.

Power the board from USB

Required

Use a single USB cable to power the board through its native connector. Leave external power headers disconnected. Check the 3.3 V rail before attaching the debug probe.

Bench checks

  • Identify the USB power input and ground in the board schematic.
  • Measure roughly 3.3 V between the board logic rail and ground. Check for a short or wrong connector if the rail is low.

STM32F103C8T6 Blue Pill connector map

Connection scenarios

Measure a single timer voice

Configure one voice for TIM1_CH1 on PA8. Power the board by USB and connect a 10× oscilloscope probe to A8. The probe reference goes to the board ground.

Bench checks

  • Start with a known note such as 440 Hz. Verify a period close to 2.27 ms.
  • Enable the other voices one at a time and confirm that each uses a distinct timer and mapped output.

STM32-TimerTone project and STMicroelectronics RM0008, advanced-control timer chapter.

STM32F103C8T6 Blue Pill wiring map

Highlighted contacts are used in the required step or selected circuit. Select a contact to inspect it.

Header 1
Use the board connector marking and locate contact 1 before wiring.
Header 2
Use the board connector marking and locate contact 1 before wiring.
SWD header
Use the board connector marking and locate contact 1 before wiring.
USB connector
Use the board connector marking and locate contact 1 before wiring.
Selected pin details

H1-12 · A7

Configurable I/O · GPIO

Routes to MCU PA7. Choose the applicable GPIO or peripheral function in the MCU documentation.

STM32F103C8T6 Blue Pill connector map

Electrical limits · Pin in the reference

Models and documents

The bench circuit measures one configured voice on PA8 (TIM1_CH1). The original project allows you to choose a channel on each timer. For acoustic output use a high-impedance amplifier input or an appropriate driver.

STM32F103C8T6 Blue Pill
The documented blue PCB has two 20-contact headers, SWD and Micro USB. Its PC13 user LED is active low. The USB D+ pull-up varies across production boards.