First commit

.gitignore

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+!.vscode/settings.json
+.vscode

Inc/mmr_can.h

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+#ifndef INC_MMR_CAN_H_
+#define INC_MMR_CAN_H_
+
+#include <stdint.h>
+#include <stdbool.h>
+#include "mmr_can_includes.h"
+#include "mmr_can_types.h"
+#include "mmr_can_optimize.h"
+
+#define MMR_CAN_RX_FIFO CAN_RX_FIFO0
+
+
+#if MMR_CAN_RX_FIFO == CAN_RX_FIFO0
+#define MMR_CAN_RX_INTERRUPT CAN_IT_RX_FIFO0_MSG_PENDING
+#else
+#define MMR_CAN_RX_INTERRUPT CAN_IT_RX_FIFO1_MSG_PENDING
+#endif
+
+#define MMR_CAN_ID 0x103
+#define MMR_CAN_BUFFER_LEN 8
+
+typedef uint8_t CanRxBuffer[MMR_CAN_BUFFER_LEN];
+
+
+typedef struct {
+  bool enabled;
+
+  /**
+   * The fifo that the filter should operate
+   * on
+   */
+  CanFilterFifo fifo;
+
+  /**
+   * The filter bank to use
+   *
+   * In systems with more than one CAN interface,
+   * this must go from 0 to slaveBankStart.
+   */
+  CanFilterBank bank;
+
+  /**
+   * The start of the slave filter banks.
+   * This value is ignored for single-CAN boards.
+   */
+  CanFilterBank slaveBankStart;
+
+  /**
+   * The mask to use with this filter.
+   */
+  CanFilterMask idMask;
+} MmrCanFilterSettings;
+
+typedef struct {
+  /**
+   * The id of the CAN interface that will receive the packet.
+   *
+   * If you are using the CANbus in loopback mode, it can be the
+   * id that the sender is using.
+   */
+  CanId remoteId;
+  CanMailbox *mailbox;
+  uint8_t *data;
+  uint8_t length;
+} MmrCanPacket;
+
+
+#define MMR_CAN_FilterConfigDefault(phcan) \
+  MMR_CAN_FilterConfig(phcan, MMR_CAN_GetDefaultFilterSettings())
+
+HalStatus MMR_CAN_FilterConfig(CanHandle *hcan, MmrCanFilterSettings settings);
+CanFilterMask MMR_CAN_AlignStandardMask(CanFilterMask baseMask);
+MmrCanFilterSettings MMR_CAN_GetDefaultFilterSettings();
+
+HalStatus MMR_CAN_Send(CanHandle *hcan, MmrCanPacket packet);
+
+#endif /* INC_MMR_CAN_H_ */

Inc/mmr_can_incudes.h

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+#ifndef INC_MMR_CAN_INCLUDES_H_
+#define INC_MMR_CAN_INCLUDES_H_
+
+#include "stm32f3xx_hal.h"
+
+#ifndef CAN
+#define CAN
+#endif
+
+
+#endif /* INC_MMR_CAN_INCLUDES_H_ */

Inc/mmr_can_optimize.h

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+#ifndef INC_MMR_CAN_OPTIMIZE_H_
+#define INC_MMR_CAN_OPTIMIZE_H_
+
+#ifdef __GNUC__
+#define always_inline inline __attribute__((always_inline))
+#else
+#define always_inline inline
+#endif
+
+#endif /* INC_OPTIMIZE_H_ */

Inc/mmr_can_types.h

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+#ifndef INC_MMR_CAN_TYPES_H_
+#define INC_MMR_CAN_TYPES_H_
+
+#include <stdint.h>
+#include "mmr_can_incudes.h"
+
+typedef uint32_t CanId;
+typedef uint32_t CanMailbox;
+
+/**
+ * A filter mask for the CANbus.
+ * It acts like a subnet mask, filtering the ids that
+ * do not match it.
+ * 
+ * The value 0 can be used to let any message pass through.
+ * 
+ * You should use the MMR_CAN_AlignStandardMask function
+ * to align the mask when using standard masks.
+ */
+typedef uint32_t CanFilterMask;
+
+/**
+ * Stores a value from CAN_filter_FIFO
+ * That is, CAN_FILTER_FIFOx
+ */
+typedef uint8_t CanFilterFifo;
+
+/** 
+ * Represents a filter bank.
+ * The values must be in the range [0, 27]
+ */
+typedef uint8_t CanFilterBank;
+
+typedef HAL_StatusTypeDef HalStatus;
+typedef CAN_HandleTypeDef CanHandle;
+
+#endif /* INC_MMR_TYPES_H_ */

Inc/mmr_can_util.h

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+#ifndef INC_MMR_CAN_UTIL_H_
+#define INC_MMR_CAN_UTIL_H_
+
+#include <stdint.h>
+#include <string.h>
+
+#define stringArrayLength(array) \
+  stringBufferLength((array), sizeof(array))
+
+size_t stringBufferLength(uint8_t *buffer, size_t maxLen) {
+  return strnlen((const char*)buffer, maxLen);
+}
+
+#endif /* INC_UTIL_H_ */

Src/mmr_can.c

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+#include "mmr_can.h"
+
+
+HalStatus MMR_CAN_FilterConfig(CanHandle *hcan, MmrCanFilterSettings settings) {
+  CAN_FilterTypeDef filter = {
+    .FilterActivation = settings.enabled
+      ? CAN_FILTER_ENABLE
+      : CAN_FILTER_DISABLE,
+
+    .FilterIdHigh = settings.idMask,
+    .FilterMaskIdHigh = settings.idMask,
+    .FilterFIFOAssignment = settings.fifo,
+    .FilterBank = settings.bank,
+    .SlaveStartFilterBank = settings.slaveBankStart,
+    .FilterMode = CAN_FILTERMODE_IDMASK,
+    .FilterScale = CAN_FILTERSCALE_32BIT,
+  };
+
+  return HAL_CAN_ConfigFilter(hcan, &filter);
+}
+
+CanFilterMask MMR_CAN_AlignStandardMask(CanFilterMask baseMask) {
+  static const uint8_t extendedMaskSurplusBytes = 5;
+  return baseMask << extendedMaskSurplusBytes;
+}
+
+MmrCanFilterSettings MMR_CAN_GetDefaultFilterSettings() {
+  return (MmrCanFilterSettings) {
+    .enabled = true,
+    .fifo = MMR_CAN_RX_FIFO,
+    .idMask = 0,
+    .bank = 0,
+    .slaveBankStart = 14,
+  };
+}
+
+
+HalStatus MMR_CAN_Send(CanHandle *hcan, MmrCanPacket packet) {
+  CAN_TxHeaderTypeDef header = {
+    .IDE = CAN_ID_STD,
+    .RTR = CAN_RTR_DATA,
+    .DLC = packet.length,
+    .StdId = packet.slaveId,
+    .TransmitGlobalTime = DISABLE,
+  };
+
+  return HAL_CAN_AddTxMessage(hcan, &header, packet.data, packet.mailbox);
+}
+
+
+static void __handleCanRxInterrupt(CAN_HandleTypeDef *hcan) {
+  static CAN_RxHeaderTypeDef rxHeader = {};
+  static CanRxBuffer rxData = {};
+
+  HAL_CAN_GetRxMessage(hcan, MMR_CAN_RX_FIFO, &rxHeader, rxData);
+}
+
+#if MMR_CAN_RX_FIFO == CAN_RX_FIFO0
+void HAL_CAN_RxFifo0MsgPendingCallback(CAN_HandleTypeDef *hcan) {
+  __handleCanRxInterrupt(hcan);
+}
+#elif MMR_CAN_RX_FIFO == CAN_RX_FIFO1
+void HAL_CAN_RxFifo1MsgPendingCallback(CAN_HandleTypeDef *hcan) {
+  __handleCanRxInterrupt(hcan);
+}
+#endif