prelimnary can handler

Core/Inc/can_handler.h

@@ -0,0 +1,14 @@
+#ifndef CAN_HANDLER_H
+#define CAN_HANDLER_H
+
+#include "stm32f4xx_hal.h"
+
+can_t can1;
+can_t can2;
+
+/* Shepherd hanbdles both can busses the same way */
+void can_receive_callback(CAN_HandleTypeDef *hcan);
+
+void get_can_msg();
+
+#endif // CAN_HANDLER_H

Core/Src/can_handler.c

@@ -0,0 +1,38 @@
+#include "can_handler.h"
+#include "can.h"
+#include "ringbuffer.h"
+
+#define NUM_INBOUND_CAN1_IDS 1
+#define NUM_INBOUND_CAN2_IDS 1
+
+ringbuffer_t can_receive_queue;
+
+
+
+static const uint16_t i can1_id_list[NUM_INBOUND_CAN1_IDS] = {
+	//CANID_X,
+	NULL
+};
+
+static const uint16_t i can2_id_list[NUM_INBOUND_CAN2_IDS] = {
+	//CANID_X,
+	NULL
+};
+
+void can_receive_callback(CAN_HandleTypeDef *hcan)
+{
+    CAN_RxHeaderTypeDef rx_header;
+    can_msg_t new_msg;
+    /* Read in CAN message */
+	if (HAL_CAN_GetRxMessage(hcan, CAN_RX_FIFO0, &rx_header, new_msg.data) != HAL_OK) {
+
+        // TODO add non crtical fault capability - could create one for failed can receieve
+        return;
+    }
+
+    new_msg.len = rx_header.DLC;
+	new_msg.id = rx_header.StdId;
+
+    enqueue(can_receive_queue, new_msg.data);
+}
+