From d1025b6b5d98686abdf9d8c450f07da27e3b6012 Mon Sep 17 00:00:00 2001
From: Me No Dev <me-no-dev@users.noreply.github.com>
Date: Fri, 9 Dec 2016 12:51:36 +0200
Subject: [PATCH] Update esp32-hal-i2c.c

wait for data to be latched and increase timeout in attempt to fix clock stretch issues
Connected issues:
http://esp32.com/viewtopic.php?f=19&t=632&p=2832#p2801
https://github.com/espressif/arduino-esp32/issues/81
https://github.com/espressif/arduino-esp32/issues/53
https://github.com/espressif/arduino-esp32/issues/11
---
 cores/esp32/esp32-hal-i2c.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/cores/esp32/esp32-hal-i2c.c b/cores/esp32/esp32-hal-i2c.c
index ca7bc441..8fbb0b27 100644
--- a/cores/esp32/esp32-hal-i2c.c
+++ b/cores/esp32/esp32-hal-i2c.c
@@ -172,9 +172,13 @@ i2c_err_t i2cWrite(i2c_t * i2c, uint16_t address, bool addr_10bit, uint8_t * dat
             }
         }
         i = 0;
+        uint32_t fifotail = 0;
         while(i<dataSend) {
+            fifotail = i2c->dev->fifo_st.tx_fifo_end_addr;
             i++;
             i2c->dev->fifo_data.data = data[index++];
+            // Wait for FIFO to update
+            while(i2c->dev->fifo_st.tx_fifo_end_addr == fifotail) {};
         }
         i2cSetCmd(i2c, 1, I2C_CMD_WRITE, willSend, false, false, true);
         dataLen -= willSend;
@@ -389,7 +393,7 @@ i2c_t * i2cInit(uint8_t i2c_num, uint16_t slave_addr, bool addr_10bit_en)
     i2c->dev->ctr.scl_force_out = 1 ;
     i2c->dev->ctr.clk_en = 1;
 
-    i2c->dev->timeout.tout = 2000;
+    i2c->dev->timeout.tout = 400000;//clocks max=1048575
     i2c->dev->fifo_conf.nonfifo_en = 0;
 
     i2c->dev->slave_addr.val = 0;