From 57e2b78f4bcbf4ff971df84ee1ad94cc569e3b9c Mon Sep 17 00:00:00 2001
From: Sara Damiano <sdamiano@stroudcenter.org>
Date: Fri, 22 Feb 2019 17:37:04 -0500
Subject: [PATCH] Checking CEREG for ublox LTE-M

---
 src/TinyGsmClientUBLOX.h | 13 ++++++++++---
 1 file changed, 10 insertions(+), 3 deletions(-)

diff --git a/src/TinyGsmClientUBLOX.h b/src/TinyGsmClientUBLOX.h
index f323394..f5a4a9f 100644
--- a/src/TinyGsmClientUBLOX.h
+++ b/src/TinyGsmClientUBLOX.h
@@ -444,9 +444,16 @@ public:
   }
 
   RegStatus getRegistrationStatus() {
-    sendAT(GF("+CGREG?"));
-    if (waitResponse(GF(GSM_NL "+CGREG:")) != 1) {
-      return REG_UNKNOWN;
+
+    if (isCatM) {  // Check EPS registration for LTE modules
+      sendAT(GF("+CEREG?"));
+      if (waitResponse(GF(GSM_NL "+CEREG:")) != 1) {
+        return REG_UNKNOWN;
+    }
+    else {
+      sendAT(GF("+CGREG?"));  // Check GPRS registration for others
+      if (waitResponse(GF(GSM_NL "+CGREG:")) != 1) {
+        return REG_UNKNOWN;
     }
     streamSkipUntil(','); // Skip format (0)
     int status = stream.readStringUntil('\n').toInt();