From d27cd19daa9156e0d98b91e588c0494b7ce6466a Mon Sep 17 00:00:00 2001
From: Tom Pittenger <magicrub@gmail.com>
Date: Thu, 7 Feb 2019 00:00:36 -0700
Subject: [PATCH] AP_RPM: instance range should use define instead of hardcoded
 value

---
 libraries/AP_RPM/RPM_Backend.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libraries/AP_RPM/RPM_Backend.h b/libraries/AP_RPM/RPM_Backend.h
index d267b38b46..fee8d9719b 100644
--- a/libraries/AP_RPM/RPM_Backend.h
+++ b/libraries/AP_RPM/RPM_Backend.h
@@ -32,7 +32,7 @@ public:
     virtual void update() = 0;
 
     int8_t get_pin(void) const {
-        if (state.instance > 1) {
+        if (state.instance >= RPM_MAX_INSTANCES) {
             return -1;
         }
         return ap_rpm._pin[state.instance].get();