From d827b35e57e916d3e670c23ee71ccc708fc31c36 Mon Sep 17 00:00:00 2001
From: Andrew Tridgell <andrew@tridgell.net>
Date: Tue, 20 Jul 2021 14:20:16 +1000
Subject: [PATCH] AP_RPM: implement arming_checks()

---
 libraries/AP_RPM/AP_RPM.cpp | 21 +++++++++++++++++++++
 libraries/AP_RPM/AP_RPM.h   |  3 +++
 2 files changed, 24 insertions(+)

diff --git a/libraries/AP_RPM/AP_RPM.cpp b/libraries/AP_RPM/AP_RPM.cpp
index e236bd307b..59008aef71 100644
--- a/libraries/AP_RPM/AP_RPM.cpp
+++ b/libraries/AP_RPM/AP_RPM.cpp
@@ -223,6 +223,27 @@ bool AP_RPM::get_rpm(uint8_t instance, float &rpm_value) const
     return true;
 }
 
+// check settings are valid
+bool AP_RPM::arming_checks(size_t buflen, char *buffer) const
+{
+    for (uint8_t i=0; i<RPM_MAX_INSTANCES; i++) {
+        switch (_type[i]) {
+        case RPM_TYPE_PWM:
+        case RPM_TYPE_PIN:
+            if (_pin[i] == -1) {
+                hal.util->snprintf(buffer, buflen, "RPM[%u] no pin set", i + 1);
+                return false;
+            }
+            if (!hal.gpio->valid_pin(_pin[i])) {
+                hal.util->snprintf(buffer, buflen, "RPM[%u] pin %d invalid", i + 1, _pin[i]);
+                return false;
+            }
+            break;
+        }
+    }
+    return true;
+}
+
 // singleton instance
 AP_RPM *AP_RPM::_singleton;
 
diff --git a/libraries/AP_RPM/AP_RPM.h b/libraries/AP_RPM/AP_RPM.h
index 240acd3d49..ad02878200 100644
--- a/libraries/AP_RPM/AP_RPM.h
+++ b/libraries/AP_RPM/AP_RPM.h
@@ -96,6 +96,9 @@ public:
 
     static AP_RPM *get_singleton() { return _singleton; }
 
+    // check settings are valid
+    bool arming_checks(size_t buflen, char *buffer) const;
+
 private:
     static AP_RPM *_singleton;