detect ack

commaai · Jun 15, 2018 · 8efa389 · 8efa389
1 parent f5fab4b
commit 8efa389
Showing 1 changed file with 7 additions and 0 deletions.
diff --git a/board/drivers/canbitbang.h b/board/drivers/canbitbang.h
@@ -134,13 +134,20 @@ void TIM4_IRQHandler(void) {
         gmlan_silent_count++;
       }
     } else if (gmlan_silent_count == REQUIRED_SILENT_TIME) {
+      int retry = 0;
       // in send loop
       if (gmlan_sending > 0 &&  // not first bit
          (read == 0 && pkt_stuffed[gmlan_sending-1] == 1) &&  // bus wrongly dominant
          gmlan_sending != (gmlan_sendmax-11)) {    //not ack bit
         puts("GMLAN ERR: bus driven at ");
         puth(gmlan_sending);
         puts("\n");
+        retry = 1;
+      } else if (read == 1 && gmlan_sending == (gmlan_sendmax-11)) {    // recessive during ACK
+        puts("GMLAN ERR: didn't recv ACK\n");
+        retry = 1;
+      }
+      if (retry) {
         // reset sender (retry after 7 silent)
         set_bitbanged_gmlan(1); // recessive
         gmlan_silent_count = 0;