From f7ae6d3117529df394de261515654904f6c0dd00 Mon Sep 17 00:00:00 2001
From: Felix Rusu <felix@lowpowerlab.com>
Date: Thu, 30 Jul 2020 12:46:42 -0400
Subject: [PATCH] freeRAM fix (SAMD)

---
 Examples/PiGateway/PiGateway.ino | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/Examples/PiGateway/PiGateway.ino b/Examples/PiGateway/PiGateway.ino
index d8c9002..929d532 100644
--- a/Examples/PiGateway/PiGateway.ino
+++ b/Examples/PiGateway/PiGateway.ino
@@ -417,9 +417,10 @@ void handleSerialData() {
 }
 
 //returns # of unfragmented free RAM bytes (free end of heap)
+extern "C" char *sbrk(int i);
 int freeRAM() {
 #ifdef __arm__
-  char top;
+  char top=0;
   return &top - reinterpret_cast<char*>(sbrk(0));
 #else
   extern int __heap_start, *__brkval;