diff --git a/ESPMegaPRO-OS-SDK/src/main.cpp b/ESPMegaPRO-OS-SDK/src/main.cpp
index 4c79918..7385028 100644
--- a/ESPMegaPRO-OS-SDK/src/main.cpp
+++ b/ESPMegaPRO-OS-SDK/src/main.cpp
@@ -27,6 +27,7 @@
 //  #define CT_ENABLE
 //  #define SMART_VARIABLE_ENABLE
 #define EXTERNAL_DIGITAL_OUTPUT_CARD_ENABLE
+#define EXTERNAL_DIGITAL_INPUT_CARD_ENABLE
 // Demo PLC firmware using the ESPMegaPRO OOP library
 
 ESPMegaPRO espmega = ESPMegaPRO();
@@ -35,6 +36,15 @@ ESPMegaPRO espmega = ESPMegaPRO();
 DigitalOutputCard externalDigitalOutputCard = DigitalOutputCard(1, 0, 1, 1, 0);
 #endif
 
+#ifdef EXTERNAL_DIGITAL_INPUT_CARD_ENABLE
+void handleExternalDigitalInput(uint8_t pin, uint8_t state)
+{
+    Serial.printf("Digital Input External %d: %d\n", pin, state);
+}
+
+DigitalInputCard externalDigitalInputCard = DigitalInputCard(1, 0, 1, 1, 1, 0);
+#endif
+
 // Remote Variable
 #ifdef REMOTE_VARIABLE_ENABLE
 RemoteVariable testVar = RemoteVariable();
@@ -172,6 +182,10 @@ void setup()
     espmega.begin();
 #ifdef EXTERNAL_DIGITAL_OUTPUT_CARD_ENABLE
     espmega.installCard(6, &externalDigitalOutputCard);
+#endif
+#ifdef EXTERNAL_DIGITAL_INPUT_CARD_ENABLE
+    espmega.installCard(7, &externalDigitalInputCard);
+    externalDigitalInputCard.registerCallback(handleExternalDigitalInput);
 #endif
     espmega.setTimezone("UTC-7");
     ESP_LOGI("Initializer", "Enabling IOT module");
@@ -216,6 +230,10 @@ void setup()
     ESP_LOGI("Initializer", "Registering cards 6");
     espmega.iot->registerCard(6);
 #endif
+#ifdef EXTERNAL_DIGITAL_INPUT_CARD_ENABLE
+    // ESP_LOGI("Initializer", "Registering cards 7");
+    // espmega.iot->registerCard(7);
+#endif
 #endif
     ESP_LOGI("Initializer", "Registering Input change callback");
     espmega.inputs.registerCallback(input_change_callback);