From 1112d77c3dc7a8ab7e8dc6e0193a7fbb95840fad Mon Sep 17 00:00:00 2001
From: David Gauchard <gauchard@laas.fr>
Date: Thu, 5 Mar 2020 18:25:12 +0100
Subject: [PATCH] less warnings on featherM0

---
 cores/arduino/math_helper.c   | 6 ++++--
 cores/arduino/wiring_analog.c | 2 +-
 libraries/SPI/SPI.h           | 2 +-
 3 files changed, 6 insertions(+), 4 deletions(-)

diff --git a/cores/arduino/math_helper.c b/cores/arduino/math_helper.c
index da6d47b0..477d4616 100644
--- a/cores/arduino/math_helper.c
+++ b/cores/arduino/math_helper.c
@@ -164,7 +164,8 @@ void arm_float_to_q12_20(float *pIn, q31_t * pOut, uint32_t numSamples)
 uint32_t arm_compare_fixed_q15(q15_t *pIn, q15_t * pOut, uint32_t numSamples)
 {
   uint32_t i; 
-  int32_t diff, diffCrnt = 0;
+  int32_t diff;
+  uint32_t diffCrnt;
   uint32_t maxDiff = 0;
 
   for (i = 0; i < numSamples; i++)
@@ -192,7 +193,8 @@ uint32_t arm_compare_fixed_q15(q15_t *pIn, q15_t * pOut, uint32_t numSamples)
 uint32_t arm_compare_fixed_q31(q31_t *pIn, q31_t * pOut, uint32_t numSamples)
 {
   uint32_t i; 
-  int32_t diff, diffCrnt = 0;
+  int32_t diff;
+  uint32_t diffCrnt;
   uint32_t maxDiff = 0;
 
   for (i = 0; i < numSamples; i++)
diff --git a/cores/arduino/wiring_analog.c b/cores/arduino/wiring_analog.c
index 13a0191b..f809c32a 100644
--- a/cores/arduino/wiring_analog.c
+++ b/cores/arduino/wiring_analog.c
@@ -32,7 +32,7 @@ static int _writeResolution = 12;
 static int _dacResolution = 12;
 #else
 static int _writeResolution = 8;
-static int _dacResolution = 10;
+//static int _dacResolution = 10;
 #endif
 
 
diff --git a/libraries/SPI/SPI.h b/libraries/SPI/SPI.h
index b87175ea..48c3cb7b 100644
--- a/libraries/SPI/SPI.h
+++ b/libraries/SPI/SPI.h
@@ -149,7 +149,7 @@ class SPIClass {
 #else
   // On SAMD21, this compiles to nothing, so user code doesn't need to
   // check and conditionally compile lines for different architectures.
-  void setClockSource(SercomClockSource clk) { };
+  void setClockSource(__attribute__((unused)) SercomClockSource clk) { };
 #endif // end __SAMD51__
 
   private: