From cc4aedb5ccd849b51558cbea432dc289206dcec3 Mon Sep 17 00:00:00 2001
From: Markus Blaschke <mblaschke82@gmail.com>
Date: Tue, 17 Aug 2021 20:00:40 +0200
Subject: [PATCH] fix cpm value

Signed-off-by: Markus Blaschke <mblaschke82@gmail.com>
---
 serial.go | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/serial.go b/serial.go
index 51d2d52..d71a6ac 100644
--- a/serial.go
+++ b/serial.go
@@ -115,7 +115,7 @@ func (d *GqGmcDevice) GetCpm() (cpm *float64) {
 	}
 
 	if buf, err := d.read(2); err == nil {
-		if len(buf) == 1 {
+		if len(buf) == 2 {
 			val := float64(binary.BigEndian.Uint16(buf))
 			cpm = &val
 		}