From f3af437774e33b9c396141cdc4a702778f889efa Mon Sep 17 00:00:00 2001
From: me-no-dev <hristo@espressif.com>
Date: Mon, 10 Oct 2016 13:53:55 +0300
Subject: [PATCH] I2C SDA should properly register the ACK bit from some slaves

---
 cores/esp32/esp32-hal-i2c.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/cores/esp32/esp32-hal-i2c.c b/cores/esp32/esp32-hal-i2c.c
index 71c153c0..83a527c0 100644
--- a/cores/esp32/esp32-hal-i2c.c
+++ b/cores/esp32/esp32-hal-i2c.c
@@ -26,7 +26,7 @@
 
 void i2cAttachSCL(i2c_t * i2c, int8_t scl)
 {
-    pinMode(scl, INPUT);
+    pinMode(scl, OUTPUT_OPEN_DRAIN);
     pinMatrixOutAttach(scl, I2C_SCL_IDX(i2c->num), false, false);
     pinMatrixInAttach(scl, I2C_SCL_IDX(i2c->num), false);
 }
@@ -40,7 +40,7 @@ void i2cDetachSCL(i2c_t * i2c, int8_t scl)
 
 void i2cAttachSDA(i2c_t * i2c, int8_t sda)
 {
-    pinMode(sda, INPUT);
+    pinMode(sda, OUTPUT_OPEN_DRAIN);
     pinMatrixOutAttach(sda, I2C_SDA_IDX(i2c->num), false, false);
     pinMatrixInAttach(sda, I2C_SDA_IDX(i2c->num), false);
 }