STM32F401CCU6 microSD Logging When the Package Cannot Expose SDIO
Design a bounded STM32F401CCU6 microSD logger around UQFN48 pin bonding, SPI transport, FatFs buffer ownership, and an explicit synchronization policy.
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Zephyr LwM2M Fleet Onboarding: Separate Bootstrap, Registration and Product Acceptance
Define distinct commissioning milestones for Zephyr LwM2M devices, then qualify credential persistence, operational identity and authorized recovery before fleet deployment.
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Designing Zephyr Inter-Core IPC: When Control and Bulk Traffic Should Share an Instance
For a product split across two firmware domains, do separate IPC endpoints provide independent transport capacity and RX execution, or should control and bulk traffic use separately budgeted instances?
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TinyML Image Inputs: Preserve Edge Impulse’s Packed-Pixel Signal Before DSP
Why can a camera frame look correct and have the expected dimensions, yet an Edge Impulse image impulse receives incorrect features after a custom get_data adapter returns normalized channels or grayscale bytes?
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TinyML Multiple Impulses: A Model Handle Does Not Isolate Continuous-Inference Windows
Can two ongoing audio streams or two continuous audio impulses safely alternate calls through different Edge Impulse handles in one generated SDK, and does serializing calls establish independent history?
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Zephyr DMA Filter Callbacks: Do Not Return errno-Style Status from a Boolean Predicate
Why can a custom DMA channel filter reject every valid channel, or accept an invalid one, when its author uses zero for success and a negative errno for rejection?
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Zephyr nrfx Watchdog Channels: Hardware Channel IDs Do Not Create Independent Timeout Windows
Why does a second wdt_install_timeout call fail with -EINVAL when two workers request different timeout values, even though the device has another watchdog channel?
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Zephyr ADC Async Completion: A Zero Signal Result Does Not Certify the Requested Sampling Interval
Why can an interval-overrun path report -EBUSY to a synchronous ADC reader while the asynchronous completion signal carries zero, even though the shared context recorded the overrun?
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Zephyr PWM Channels on One nrfx Instance: A Second Period Can Fail While the First Output Is Active
Why does a second PWM output work alone but return -EINVAL when another channel on the same controller is already generating a different period?
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STM32F401CCU6 Temperature and VBAT Readings: Resolve the Shared ADC18 Path Before Building a Scan
Why does enabling VBAT monitoring replace the temperature result, even when the scan has separate ranks intended for the two internal measurements?
