From b880559ba78b08756024c35a437a7802e3aec990 Mon Sep 17 00:00:00 2001
From: "D.R.racer" <drracer@drracer.eu>
Date: Fri, 10 Jun 2022 08:21:34 +0200
Subject: [PATCH] Reset MMU upon start + fix reporting its start errors

---
 Firmware/mmu2.cpp                |  4 +++-
 Firmware/mmu2_protocol_logic.cpp | 13 +++++++++++++
 2 files changed, 16 insertions(+), 1 deletion(-)

diff --git a/Firmware/mmu2.cpp b/Firmware/mmu2.cpp
index ccc1dbba3..1917383c8 100644
--- a/Firmware/mmu2.cpp
+++ b/Firmware/mmu2.cpp
@@ -103,7 +103,9 @@ void MMU2::Start() {
 
     mmu2Serial.begin(MMU_BAUD);
 
-    PowerOn();
+    // PowerOn(); we cannot do that on MK3, but at least reset the MMU
+    Reset(ResetForm::ResetPin);
+
     mmu2Serial.flush(); // make sure the UART buffer is clear before starting communication
 
     extruder = MMU2_NO_TOOL;
diff --git a/Firmware/mmu2_protocol_logic.cpp b/Firmware/mmu2_protocol_logic.cpp
index 35c65b1b6..12134d010 100644
--- a/Firmware/mmu2_protocol_logic.cpp
+++ b/Firmware/mmu2_protocol_logic.cpp
@@ -294,6 +294,19 @@ StepStatus Idle::Step() {
                 logic->SwitchFromIdleToCommand();
                 return Processing;
             }
+            break;
+        case RequestMsgCodes::Reset:
+            // this one is kind of special
+            // we do not transfer to any "running" command (i.e. we stay in Idle),
+            // but in case there is an error reported we must make sure it gets propagated
+            if( logic->rsp.paramCode != ResponseMsgParamCodes::Finished ){
+                logic->errorCode = static_cast<ErrorCode>(logic->rsp.paramValue);
+                SendFINDAQuery(); // continue Idle state without restarting the communication
+                return CommandError;
+            } else {
+                logic->errorCode = ErrorCode::OK;
+            }
+            break;
         default:
             break;
         }