Uplink

Telemetry Queue Burst Bug Debug

Symptom

Spaced pulses report correctly. After a fast burst the report starts with the last samples, repeats them, and never shows the first ones. The registers and bit fields are on the Datasheet tab.

Circuit

Block diagram: U2 vibration sensor drives a strobe into PA0 and a four-bit value onto PA1 to PA4 of U1 STM32F4, and PA9 carries the USART1 report to TP1, a serial monitor

Pass condition

Each sample sent gets one SAMPLE:<value> line in arrival order. TOTAL:<n> and DROPPED:<n> follow when the sensor goes quiet. Every pulse is accounted for.

Expected output for twelve pulses 200 us apart carrying 7 3 12 9 1 14 6 11 5 2 13 8: the report is the first eight values in order, then TOTAL:8 and DROPPED:4

Notes

The bench is the vibration sensor. It sets each sample on PA1 to PA4, strobes PA0, bursts included, then falls silent. The uplink takes one line about every 4 ms.

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