From 61c67be510141a08791fee34c078d88bb002ecbe Mon Sep 17 00:00:00 2001
From: MichaelDvP <github@mdvp.de>
Date: Fri, 29 Jan 2021 11:27:56 +0100
Subject: [PATCH] dallas: bus not idle error handling

---
 src/dallassensor.cpp | 20 +++++++++++++++-----
 src/dallassensor.h   |  6 +++++-
 2 files changed, 20 insertions(+), 6 deletions(-)

diff --git a/src/dallassensor.cpp b/src/dallassensor.cpp
index 8f9667bf8..2469405d0 100644
--- a/src/dallassensor.cpp
+++ b/src/dallassensor.cpp
@@ -69,10 +69,20 @@ void DallasSensor::loop() {
                 YIELD;
                 bus_.skip();
                 bus_.write(CMD_CONVERT_TEMP, parasite_ ? 1 : 0);
-                state_ = State::READING;
+                state_     = State::READING;
+                scanretry_ = 0;
             } else {
                 // no sensors found
-                // LOG_ERROR(F("Bus reset failed")); // uncomment for debug
+                if (sensors_.size()) {
+                    sensorfails_++;
+                    if (++scanretry_ > SCAN_MAX) { // every 30 sec
+                        scanretry_ = 0;
+                        LOG_ERROR(F("Bus reset failed"));
+                        for (auto & sensor : sensors_) {
+                            sensor.temperature_c = EMS_VALUE_SHORT_NOTSET;
+                        }
+                    }
+                }
             }
             last_activity_ = time_now;
         }
@@ -142,7 +152,7 @@ void DallasSensor::loop() {
                     bus_.depower();
                 }
                 // check for missing sensors after some samples
-                if (++scancnt_ > 5) {
+                if (++scancnt_ > SCAN_MAX) {
                     for (auto & sensor : sensors_) {
                         if (!sensor.read) {
                             sensor.temperature_c = EMS_VALUE_SHORT_NOTSET;
@@ -151,11 +161,11 @@ void DallasSensor::loop() {
                         sensor.read = false;
                     }
                     scancnt_ = 0;
-                } else if (scancnt_ == -2) { // startup
+                } else if (scancnt_ == SCAN_START + 1) { // startup
                     firstscan_ = sensors_.size();
                     LOG_DEBUG(F("Adding %d dallassensor(s) from first scan"), firstscan_);
                 } else if ((scancnt_ <= 0) && (firstscan_ != sensors_.size())) { // check 2 times for no change of sensor #
-                    scancnt_ = -3;
+                    scancnt_ = SCAN_START;
                     sensors_.clear(); // restart scaning and clear to get correct numbering
                 }
                 state_ = State::IDLE;
diff --git a/src/dallassensor.h b/src/dallassensor.h
index 40e6bfe89..7d3ea8204 100644
--- a/src/dallassensor.h
+++ b/src/dallassensor.h
@@ -95,6 +95,9 @@ class DallasSensor {
     static constexpr uint8_t CMD_CONVERT_TEMP    = 0x44;
     static constexpr uint8_t CMD_READ_SCRATCHPAD = 0xBE;
 
+    static constexpr int8_t  SCAN_START  = -3;
+    static constexpr int8_t  SCAN_MAX    = 5;
+
     static uuid::log::Logger logger_;
 
 #ifndef EMSESP_STANDALONE
@@ -114,12 +117,13 @@ class DallasSensor {
 
     bool registered_ha_[MAX_SENSORS];
 
-    int8_t   scancnt_     = -3;
+    int8_t   scancnt_     = SCAN_START;
     uint8_t  firstscan_   = 0;
     uint8_t  dallas_gpio_ = 0;
     bool     parasite_    = false;
     bool     changed_     = false;
     uint32_t sensorfails_ = 0;
+    int8_t   scanretry_   = 0;
 };
 
 } // namespace emsesp