From 0f3f80a1ccfbce547f3d7bc11077cbdd82a0fd29 Mon Sep 17 00:00:00 2001
From: Sandeep Mistry <s.mistry@arduino.cc>
Date: Thu, 21 Jan 2016 14:20:00 -0500
Subject: [PATCH] Only update pull-up value in digitalWrite if pin direction is
not output
---
cores/arduino/wiring_digital.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/cores/arduino/wiring_digital.c b/cores/arduino/wiring_digital.c
index 966d72bd..769bcaf7 100644
--- a/cores/arduino/wiring_digital.c
+++ b/cores/arduino/wiring_digital.c
@@ -82,8 +82,10 @@ void digitalWrite( uint32_t ulPin, uint32_t ulVal )
return ;
}
- // Enable pull-up resistor
- PORT->Group[g_APinDescription[ulPin].ulPort].PINCFG[g_APinDescription[ulPin].ulPin].reg=(uint8_t)(PORT_PINCFG_PULLEN) ;
+ if ( (PORT->Group[g_APinDescription[ulPin].ulPort].DIRSET.reg & (1ul << g_APinDescription[ulPin].ulPin)) == 0 ) {
+ // the pin is not an output, disable pull-up if val is LOW, otherwise enable pull-up
+ PORT->Group[g_APinDescription[ulPin].ulPort].PINCFG[g_APinDescription[ulPin].ulPin].bit.PULLEN = (ulVal != LOW) ;
+ }
switch ( ulVal )
{
--
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