Cortex-M23 Audio Sensor Prototype
Budget: €10,000 – €20,000 EUR
I need to turn a very small proof-of-concept into a near-production prototype over the next three to four months. The hardware is a 20 mm × 20 mm board built around a Renesas Arm Cortex-M23 in QFN-16, a 4 Mb SPI flash, a piezo driver and a capacitive-coupled SPI link for both data and in-system programming. Everything must run for months from a single CR2032, so every microamp counts.
Altium Designer is mandatory for schematic capture, layout, 3-D, and final manufacturing outputs. On the firmware side I’m set up for GCC / CMSIS in either Eclipse or a Visual-Studio-style environment, so please stick to one of those.
Key features the code has to cover
• Continuous temperature monitoring that feeds a small model driving behaviour
• Real-time generation of simple, ‘old Atari’-style MIDI melodies
• Playback of pre-stored wave snippets pulled from the external flash
• Ultra-low-power architecture with deep sleep and timer-based wake-up
Because the link to the outside world is a contactless SPI channel, the project also needs a lightweight bootloader and a desktop utility I can use to push updates through that interface.
Deliverables
• Altium project (schematic, PCB, 3-D, fabrication and assembly files)
• Fully commented C/C++ firmware project ready to build in Eclipse/VS Code
• Flash map, power budget, and short bring-up guide
• Two assembled, tested prototypes demonstrating every listed feature
If you have shipped similarly tiny, battery-powered Cortex-M boards—or have experience squeezing surprising audio out of simple piezo drivers—I’d love to hear how you would approach it.
The software also needs self calibrating of internal temperature sensor under 2 point reference environment.
Altium Designer is mandatory for schematic capture, layout, 3-D, and final manufacturing outputs. On the firmware side I’m set up for GCC / CMSIS in either Eclipse or a Visual-Studio-style environment, so please stick to one of those.
Key features the code has to cover
• Continuous temperature monitoring that feeds a small model driving behaviour
• Real-time generation of simple, ‘old Atari’-style MIDI melodies
• Playback of pre-stored wave snippets pulled from the external flash
• Ultra-low-power architecture with deep sleep and timer-based wake-up
Because the link to the outside world is a contactless SPI channel, the project also needs a lightweight bootloader and a desktop utility I can use to push updates through that interface.
Deliverables
• Altium project (schematic, PCB, 3-D, fabrication and assembly files)
• Fully commented C/C++ firmware project ready to build in Eclipse/VS Code
• Flash map, power budget, and short bring-up guide
• Two assembled, tested prototypes demonstrating every listed feature
If you have shipped similarly tiny, battery-powered Cortex-M boards—or have experience squeezing surprising audio out of simple piezo drivers—I’d love to hear how you would approach it.
The software also needs self calibrating of internal temperature sensor under 2 point reference environment.