1 files changed, 66 insertions, 0 deletions
diff --git a/center_fw/protocol.c b/center_fw/protocol.c
new file mode 100644
index 0000000..87d46e4
--- /dev/null
+++ b/center_fw/protocol.c
@@ -0,0 +1,66 @@
+
+#include <unistd.h>
+#include "protocol.h"
+#include "8b10b.h"
+
+void reset_receiver(struct proto_rx_st *st, struct command_if_def *cmd_if) {
+    st->rxpos = -1;
+    st->address = 5; /* FIXME debug code */
+    st->cmd_if = cmd_if;
+}
+
+void receive_symbol(struct proto_rx_st *st, int symbol) {
+    if (symbol == -K28_1) { /* Comma/frame delimiter */
+        st->rxpos = 0;
+        /* Fall through and return and just ignore incomplete packets */
+
+    } else if (symbol == -DECODING_ERROR) {
+        goto reset;
+
+    } else if (symbol < 0) { /* Unknown comma symbol or error */
+        goto reset;
+
+    } else if (st->rxpos == -1) {
+        return;
+
+    } else if (st->rxpos == 0) { /* First data symbol, and not an error or comma symbol */
+        st->packet_type = symbol & ~PKT_TYPE_BULK_FLAG;
+        if (st->packet_type >= st->cmd_if->packet_type_max)
+            goto reset;
+
+        int payload_len = st->cmd_if->payload_len[st->packet_type];
+        st->is_bulk = symbol & PKT_TYPE_BULK_FLAG;
+        st->offset = (st->is_bulk) ? (st->address*payload_len + 1) : 2;
+        st->rxpos++;
+
+        if (payload_len == 0 && st->is_bulk) {
+            handle_command(st->packet_type, NULL);
+            goto reset;
+        }
+
+    } else if (!st->is_bulk && st->rxpos == 1) {
+        if (symbol != st->address)
+            goto reset;
+
+        if (st->cmd_if->payload_len[st->packet_type] == 0) {
+            handle_command(st->packet_type, NULL);
+            goto reset;
+        }
+        st->rxpos = 2;
+
+    } else {
+        if (st->rxpos - st->offset >= 0)
+            st->argbuf[st->rxpos - st->offset] = symbol;
+        st->rxpos++;
+
+        if (st->rxpos - st->offset == st->cmd_if->payload_len[st->packet_type]) {
+            handle_command(st->packet_type, (uint8_t *)st->argbuf);
+            goto reset;
+        }
+    }
+
+    return;
+reset:
+    st->rxpos = -1;
+}
+