From 8792023e13f4b9413f710fb4e3a2d3fbfc74f603 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Przemys=C5=82aw=20Romaniak?= <loudpl@gmail.com>
Date: Sat, 29 Jul 2023 00:30:51 +0200
Subject: [PATCH] esp32c3: during scan retry only once on timeout

---
 lib/i2cscan/i2cscan.cpp | 12 +++++++-----
 lib/i2cscan/i2cscan.h   |  2 +-
 2 files changed, 8 insertions(+), 6 deletions(-)

diff --git a/lib/i2cscan/i2cscan.cpp b/lib/i2cscan/i2cscan.cpp
index 18793542b..5d8f22573 100644
--- a/lib/i2cscan/i2cscan.cpp
+++ b/lib/i2cscan/i2cscan.cpp
@@ -20,10 +20,10 @@ namespace I2CSCAN
 {
 
     uint8_t pickDevice(uint8_t addr1, uint8_t addr2, bool scanIfNotFound) {
-        if(I2CSCAN::isI2CExist(addr1)) {
+        if(I2CSCAN::hasDevOnBus(addr1)) {
             return addr1;
         }
-        if(I2CSCAN::isI2CExist(addr2)) {
+        if(I2CSCAN::hasDevOnBus(addr2)) {
             return addr2;
         }
         if (scanIfNotFound) {
@@ -104,23 +104,25 @@ namespace I2CSCAN
             }
             else if (error == 4)
             {
-                Serial.printf("[ERR] I2C (@ %s(%d) : %s(%d)): Unknow error at address 0x%02x\n", 
+                Serial.printf("[ERR] I2C (@ %s(%d) : %s(%d)): Unknown error at address 0x%02x\n",
                                 portMap[i].c_str(), portArray[i], portMap[j].c_str(), portArray[j], address);
             }
         }
         return found;
     }
 
-    bool isI2CExist(uint8_t addr) {
+    bool hasDevOnBus(uint8_t addr) {
         byte error;
 #if ESP32C3
+        int retries = 1;
         do {
 #endif
             Wire.beginTransmission(addr);
             error = Wire.endTransmission();
+            Wire.clearWriteError();
 #if ESP32C3
         }
-        while (error == 5);
+        while (error == 5 && retries--);
 #endif
         if(error == 0)
             return true;
diff --git a/lib/i2cscan/i2cscan.h b/lib/i2cscan/i2cscan.h
index 0ace23455..a0234db34 100644
--- a/lib/i2cscan/i2cscan.h
+++ b/lib/i2cscan/i2cscan.h
@@ -7,7 +7,7 @@
 namespace I2CSCAN {
     void scani2cports();
     bool checkI2C(uint8_t i, uint8_t j);
-    bool isI2CExist(uint8_t addr);
+    bool hasDevOnBus(uint8_t addr);
     uint8_t pickDevice(uint8_t addr1, uint8_t addr2, bool scanIfNotFound);
     int clearBus(uint8_t SDA, uint8_t SCL);
     boolean inArray(uint8_t value, uint8_t* arr, size_t arrSize);