From de85012877ec0dcc9054096bff918403629fca8c Mon Sep 17 00:00:00 2001
From: Andrey <anklimov@gmail.com>
Date: Sat, 30 Mar 2024 09:30:17 +0300
Subject: [PATCH] send hungs fix (adding timeout)

---
 src/CAN.h            | 4 ++++
 src/CANController.h  | 4 ++++
 src/ESP32SJA1000.cpp | 6 +++++-
 3 files changed, 13 insertions(+), 1 deletion(-)

diff --git a/src/CAN.h b/src/CAN.h
index d8edc06..1e7ad45 100644
--- a/src/CAN.h
+++ b/src/CAN.h
@@ -4,6 +4,10 @@
 #ifndef CAN_H
 #define CAN_H
 
+#ifndef CAN_MAXTRANSMIT_MS
+#define CAN_MAXTRANSMIT_MS 100
+#endif
+
 #ifdef ARDUINO_ARCH_ESP32
 #include "ESP32SJA1000.h"
 #else
diff --git a/src/CANController.h b/src/CANController.h
index cdaeb94..5c75564 100644
--- a/src/CANController.h
+++ b/src/CANController.h
@@ -6,6 +6,10 @@
 
 #include <Arduino.h>
 
+#ifndef CAN_MAXTRANSMIT_MS
+#define CAN_MAXTRANSMIT_MS 100
+#endif
+
 class CANControllerClass : public Stream {
 
 public:
diff --git a/src/ESP32SJA1000.cpp b/src/ESP32SJA1000.cpp
index 309e030..4bcff07 100644
--- a/src/ESP32SJA1000.cpp
+++ b/src/ESP32SJA1000.cpp
@@ -168,8 +168,10 @@ int ESP32SJA1000Class::endPacket()
     return 0;
   }
 
+  uint32_t tmr1 = millis();  
   // wait for TX buffer to free
   while ((readRegister(REG_SR) & 0x04) != 0x04) {
+      if (millis() - tmr1 >= CAN_MAXTRANSMIT_MS) return 0;
     yield();
   }
 
@@ -202,7 +204,8 @@ int ESP32SJA1000Class::endPacket()
     // transmit request
     modifyRegister(REG_CMR, 0x1f, 0x01);
   }
-
+  
+    tmr1 = millis();  
   // wait for TX complete
   while ((readRegister(REG_SR) & 0x08) != 0x08) {
     if (readRegister(REG_ECC) == 0xd9) {
@@ -210,6 +213,7 @@ int ESP32SJA1000Class::endPacket()
       return 0;
     }
     yield();
+      if (millis() - tmr1 >= CAN_MAXTRANSMIT_MS) return 0;
   }
 
   return 1;