25 lines
785 B
C
25 lines
785 B
C
// SharedSPI — global mutex for the shared SPI bus (pins MISO=33, MOSI=34, CLK=35)
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//
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// Users of this bus MUST acquire shared_spi_mutex before any SPI transaction
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// and release it after. This prevents race conditions between:
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// - SX1262 LoRa radio (CS=36) — main loop, continuous polling
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// - SD card (CS=21) — USB MSC callbacks (TinyUSB task), IMU logger, screenshots
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// - ST25R3916 NFC (CS=4) — future, not yet implemented
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//
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// The CO5300 display uses a separate SPI3 bus and does NOT need this mutex.
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#ifndef SHARED_SPI_H
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#define SHARED_SPI_H
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#include <freertos/semphr.h>
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extern SemaphoreHandle_t shared_spi_mutex;
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inline void shared_spi_init() {
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if (!shared_spi_mutex) {
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shared_spi_mutex = xSemaphoreCreateMutex();
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}
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}
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#endif // SHARED_SPI_H
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