Embedded Engineer for Flex-PCB & STM32 Firmware
Budget: $30 – $250 USD
Title: Full-Stack Embedded Engineer: KiCad Flex-PCB Design & STM32 Firmware for Capacitive Sensing Array
Project Objective:
We are prototyping a wearable biomechanics system for a para-athlete runner to measure Vertical Impact Peak (VIP) and asymmetry. The hardware architecture utilizes a custom multi-channel capacitive force sensor array (copper pads separated by a cellular polyurethane/Poron dielectric) embedded in a shoe insole/cleat.
We need a full-stack embedded systems engineer to design the custom Flexible PCB layout in KiCad and write the bare-metal C/C++ firmware for an STM32 microcontroller to process the sensor data.
Key Deliverables & Scope:
1. KiCad Flex-PCB Layout:
- Design a custom-shaped, ultra-thin Flexible PCB (Flex-PCB) insole footprint based on provided mechanical DXF profiles.
- Implement strict analog signal integrity layouts, utilizing active shielding, guard rings, and cross-hatched ground planes to aggressively isolate traces from stray capacitance and body movement noise.
- Apply flexible circuit design rules (e.g., teardrop pads, rounded trace corners) to survive continuous dynamic running cycles.
2. STM32 Firmware Development:
- Develop bare-metal or RTOS-based C/C++ drivers (using STM32 HAL or LL libraries) to interface with multiple TI FDC2214 Capacitance-to-Digital Converters via I2C.
- Optimize FDC2214 LC resonant tank circuit register configurations for high-frequency data acquisition to accurately capture fast-impact millisecond peaks.
- Implement real-time polynomial curve-fitting calibration to map raw frequency shifts to calculated force data.
- Build a clean USB-CDC data streaming protocol to export real-time array data to a PC visualization client.
Required Technical Expertise:
- High proficiency in KiCad EDA (specifically mixed-signal, low-capacitance layouts).
- Strong track record in STM32 firmware design (C/C++).
- Deep understanding of resonant LC tank capacitive sensing front-ends (TI FDC2x family strongly preferred).
- Experience designing for flexible substrates (Flex-PCBs) and handling physical sensor noise isolation.
To apply, please briefly highlight your experience with KiCad analog shielding strategies and high-speed I2C/analog sensor sampling. generic template bids will be immediately ignored.
Project Objective:
We are prototyping a wearable biomechanics system for a para-athlete runner to measure Vertical Impact Peak (VIP) and asymmetry. The hardware architecture utilizes a custom multi-channel capacitive force sensor array (copper pads separated by a cellular polyurethane/Poron dielectric) embedded in a shoe insole/cleat.
We need a full-stack embedded systems engineer to design the custom Flexible PCB layout in KiCad and write the bare-metal C/C++ firmware for an STM32 microcontroller to process the sensor data.
Key Deliverables & Scope:
1. KiCad Flex-PCB Layout:
- Design a custom-shaped, ultra-thin Flexible PCB (Flex-PCB) insole footprint based on provided mechanical DXF profiles.
- Implement strict analog signal integrity layouts, utilizing active shielding, guard rings, and cross-hatched ground planes to aggressively isolate traces from stray capacitance and body movement noise.
- Apply flexible circuit design rules (e.g., teardrop pads, rounded trace corners) to survive continuous dynamic running cycles.
2. STM32 Firmware Development:
- Develop bare-metal or RTOS-based C/C++ drivers (using STM32 HAL or LL libraries) to interface with multiple TI FDC2214 Capacitance-to-Digital Converters via I2C.
- Optimize FDC2214 LC resonant tank circuit register configurations for high-frequency data acquisition to accurately capture fast-impact millisecond peaks.
- Implement real-time polynomial curve-fitting calibration to map raw frequency shifts to calculated force data.
- Build a clean USB-CDC data streaming protocol to export real-time array data to a PC visualization client.
Required Technical Expertise:
- High proficiency in KiCad EDA (specifically mixed-signal, low-capacitance layouts).
- Strong track record in STM32 firmware design (C/C++).
- Deep understanding of resonant LC tank capacitive sensing front-ends (TI FDC2x family strongly preferred).
- Experience designing for flexible substrates (Flex-PCBs) and handling physical sensor noise isolation.
To apply, please briefly highlight your experience with KiCad analog shielding strategies and high-speed I2C/analog sensor sampling. generic template bids will be immediately ignored.
Related categories:
Electronics
Microcontroller
PCB Layout
Circuit Design
Embedded Systems
I2C
Prototyping
STM32