From db84c56e62b78c32b2147e9c75db44ba27ccc49e Mon Sep 17 00:00:00 2001
From: Steve Lascos <slascos@blackaddr.com>
Date: Sat, 18 Nov 2017 13:29:14 -0500
Subject: [PATCH] Modifity Wire write to loop until success due to possible
 issue with T3.6 teensyduino library

---
 src/BAAudioControlWM8731.cpp | 25 ++++++++++++++++++++-----
 src/BAAudioControlWM8731.h   |  4 ++--
 2 files changed, 22 insertions(+), 7 deletions(-)

diff --git a/src/BAAudioControlWM8731.cpp b/src/BAAudioControlWM8731.cpp
index 6c9b964..c394622 100644
--- a/src/BAAudioControlWM8731.cpp
+++ b/src/BAAudioControlWM8731.cpp
@@ -103,7 +103,6 @@ void BAAudioControlWM8731::resetInternalReg(void) {
 BAAudioControlWM8731::BAAudioControlWM8731()
 {
 	resetInternalReg();
-	Wire.begin(); // start the I2C service
 }
 
 BAAudioControlWM8731::~BAAudioControlWM8731()
@@ -114,6 +113,9 @@ BAAudioControlWM8731::~BAAudioControlWM8731()
 void BAAudioControlWM8731::disable(void)
 {
 
+	Serial.println("Disabling codec");
+	if (m_wireStarted == false) { Wire.begin(); m_wireStarted = true; }
+
 	// set OUTPD to '1' (powerdown), which is bit 4
 	regArray[WM8731_REG_POWERDOWN] |= 0x10;
 	write(WM8731_REG_POWERDOWN, regArray[WM8731_REG_POWERDOWN]);
@@ -130,6 +132,8 @@ void BAAudioControlWM8731::disable(void)
 void BAAudioControlWM8731::enable(void)
 {
 
+	Serial.println("Enabling codec");
+	if (m_wireStarted == false) { Wire.begin(); m_wireStarted = true; }
 	// Sequence from WAN0111.pdf
 
 	// Begin configuring the codec
@@ -173,6 +177,8 @@ void BAAudioControlWM8731::enable(void)
 	regArray[WM8731_REG_POWERDOWN] = 0x02;
 	delay(500); // wait for output to power up
 
+	Serial.println("Done codec config");
+
 
 	delay(100); // wait for mute ramp
 
@@ -315,10 +321,19 @@ void BAAudioControlWM8731::writeI2C(unsigned int addr, unsigned int val)
 // Low level write control for the codec via the Teensy I2C interface
 bool BAAudioControlWM8731::write(unsigned int reg, unsigned int val)
 {
-	Wire.beginTransmission(WM8731_I2C_ADDR);
-	Wire.write((reg << 1) | ((val >> 8) & 1));
-	Wire.write(val & 0xFF);
-	Wire.endTransmission();
+	bool done = false;
+
+	while (!done) {
+		Wire.beginTransmission(WM8731_I2C_ADDR);
+		Wire.write((reg << 1) | ((val >> 8) & 1));
+		Wire.write(val & 0xFF);
+		if (byte error = Wire.endTransmission() ) {
+			//Serial.println(String("Wire::Error: ") + error + String(" retrying..."));
+		} else {
+			done = true;
+			//Serial.println("Wire::SUCCESS!");
+		}
+	}
 
 	return true;
 }
diff --git a/src/BAAudioControlWM8731.h b/src/BAAudioControlWM8731.h
index 538f557..b01c5a0 100644
--- a/src/BAAudioControlWM8731.h
+++ b/src/BAAudioControlWM8731.h
@@ -24,8 +24,6 @@
 #ifndef INC_BAAUDIOCONTROLWM8731_H_
 #define INC_BAAUDIOCONTROLWM8731_H_
 
-#include <Audio.h>
-
 namespace BAGuitar {
 
 constexpr int WM8731_NUM_REGS = 10; // Number of registers in the internal shadow array
@@ -123,6 +121,8 @@ private:
 	// resets the internal shadow register array
 	void resetInternalReg(void);
 
+	bool m_wireStarted = false;
+
 };
 
 } /* namespace BAGuitar */