Fixed example JsonConfigFile.ino for ESP8266

CHANGELOG.md

@@ -5,6 +5,7 @@ HEAD
 ----
 
 * Added `measureJson()` to the `ArduinoJson` namespace (PR #1069 by @nomis)
+* Fixed example `JsonConfigFile.ino` for ESP8266
 
 v6.11.3 (2019-07-22)
 -------

examples/JsonConfigFile/JsonConfigFile.ino

@@ -11,6 +11,12 @@
 //   "port": 2731
 // }
 //
+// To run this program, you need an SD card connected to the SPI bus as follows:
+// * MOSI <-> pin 11
+// * MISO <-> pin 12
+// * CLK  <-> pin 13
+// * CS   <-> pin 4
+//
 // https://arduinojson.org/v6/example/config/
 
 #include <ArduinoJson.h>
@@ -111,7 +117,8 @@ void setup() {
   while (!Serial) continue;
 
   // Initialize SD library
-  while (!SD.begin()) {
+  const int chipSelect = 4;
+  while (!SD.begin(chipSelect)) {
     Serial.println(F("Failed to initialize SD library"));
     delay(1000);
   }