DM: we have a 12 bit dac lets use

Author: deanm1278

boards.txt

@@ -41,6 +41,7 @@ adafruit_feather_m0.build.vid=0x239A
 adafruit_feather_m0.build.pid=0x800B
 adafruit_feather_m0.bootloader.tool=openocd
 adafruit_feather_m0.bootloader.file=feather/samd21_sam_ba.bin
+adafruit_feather_m0.compiler.arm.cmsis.ldflags=-larm_cortexM0l_math
 
 adafruit_feather_m0_express.name=Adafruit Feather M0 Express
 adafruit_feather_m0_express.vid.0=0x239A
@@ -172,7 +173,7 @@ adafruit_metro_m4.build.usb_product="Adafruit Metro M4"
 adafruit_metro_m4.build.usb_manufacturer="Adafruit LLC"
 adafruit_metro_m4.build.board=METRO_M4
 adafruit_metro_m4.build.core=arduino
-adafruit_metro_m4.build.extra_flags=-D__SAMD51J19A__ -D__SAMD51__ {build.usb_flags}
+adafruit_metro_m4.build.extra_flags=-D__SAMD51J19A__ -D__SAMD51__ {build.usb_flags} -DARM_MATH_CM4
 adafruit_metro_m4.build.ldscript=linker_scripts/gcc/flash_with_bootloader.ld
 adafruit_metro_m4.build.openocdscript=openocd_scripts/arduino_zero.cfg
 adafruit_metro_m4.build.variant=metro_m4

cores/arduino/wiring_analog.c

@@ -25,11 +25,12 @@ extern "C" {
 
 static int _readResolution = 10;
 static int _ADCResolution = 10;
-static int _writeResolution = 8;
 
 #if defined(__SAMD51__)
+static int _writeResolution = 12;
 static int _dacResolution = 12;
 #else
+static int _writeResolution = 8;
 static int _dacResolution = 8;
 #endif
 

platform.txt

@@ -65,7 +65,7 @@ compiler.ar.extra_flags=
 compiler.elf2hex.extra_flags=
 
 compiler.arm.cmsis.c.flags="-I{runtime.tools.CMSIS-4.5.0.path}/CMSIS/Include/" "-I{runtime.tools.CMSIS-Atmel-1.1.0.path}/CMSIS/Device/ATMEL/"
-compiler.arm.cmsis.ldflags="-L{runtime.tools.CMSIS-4.5.0.path}/CMSIS/Lib/GCC/" -larm_cortexM0l_math
+compiler.arm.cmsis.ldflags="-L{runtime.tools.CMSIS-4.5.0.path}/CMSIS/Lib/GCC/"
 
 # USB Flags
 # ---------