From 2eab3c9f52751b0fc2e47e181186de9042dab6eb Mon Sep 17 00:00:00 2001
From: "John M. Knutson Sr" <john.m.knutson@gmail.com>
Date: Sun, 13 Dec 2020 14:27:30 -0600
Subject: [PATCH] subzero temp fix

---
 fs/ds18b20.js | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/fs/ds18b20.js b/fs/ds18b20.js
index 9e16fc5..ccf3810 100644
--- a/fs/ds18b20.js
+++ b/fs/ds18b20.js
@@ -71,6 +71,10 @@ function getTemp(ow, rom) {
     raw = raw & ~1;
   }
   // Default resolution is 12 bit
+  //
+  if ((raw & 0x8000) > 0) {
+    raw = raw - 0x10000;
+  }
 
   return raw / 16.0;
 };