From 935cb39dff3d53e90278a814b02a8b2362e0798d Mon Sep 17 00:00:00 2001
From: Tom Pittenger <tom.pittenger@krausaerospace.com>
Date: Fri, 21 Aug 2020 09:12:39 -0700
Subject: [PATCH] AP_Math: add function to convert any base to any base

Example: convert dec 12345 to 0x12345 or dec 1200 to octal 1200
---
 libraries/AP_Math/AP_Math.cpp | 17 +++++++++++++++++
 libraries/AP_Math/AP_Math.h   |  3 +++
 2 files changed, 20 insertions(+)

diff --git a/libraries/AP_Math/AP_Math.cpp b/libraries/AP_Math/AP_Math.cpp
index 326b5ec310..8d52bfa217 100644
--- a/libraries/AP_Math/AP_Math.cpp
+++ b/libraries/AP_Math/AP_Math.cpp
@@ -128,6 +128,23 @@ float throttle_curve(float thr_mid, float alpha, float thr_in)
     return thr_out;
 }
 
+/*
+ * Convert any base number to any base number. Example octal(8) to decimal(10)
+ * baseIn: base of input number
+ * baseOut: base of output number
+ * inputNumber: value currently in base "baseIn" to be converted to base "baseOut"
+ */
+uint32_t convertMathBase(const uint8_t baseIn, const uint8_t baseOut, uint32_t inputNumber)
+{
+    uint32_t outputNumber = 0;
+
+    for (uint8_t i=0; inputNumber != 0; i++) {
+        outputNumber += (inputNumber % baseOut) * powf(float(baseIn), i);
+        inputNumber /= baseOut;
+    }
+    return outputNumber;
+}
+
 template <typename T>
 T wrap_180(const T angle)
 {
diff --git a/libraries/AP_Math/AP_Math.h b/libraries/AP_Math/AP_Math.h
index 01912a3478..85dd518df7 100644
--- a/libraries/AP_Math/AP_Math.h
+++ b/libraries/AP_Math/AP_Math.h
@@ -265,6 +265,9 @@ constexpr float expo_curve(float alpha, float input);
  */
 float throttle_curve(float thr_mid, float alpha, float thr_in);
 
+// Convert any base number to any base number. Example octal(8) to decimal(10)
+uint32_t convertMathBase(const uint8_t baseIn, const uint8_t baseOut, uint32_t inputNumber);
+
 /* simple 16 bit random number generator */
 uint16_t get_random16(void);