From 0fec0f99ca2a9c07cd95168c86b935c0f2931cd5 Mon Sep 17 00:00:00 2001
From: Dan Cogliano <cogliano@users.noreply.github.com>
Date: Tue, 28 Nov 2023 17:47:44 -0500
Subject: [PATCH] Add fast forward feature to playing sound tracks. (#74)

* Added playback speed control (i.e. 1x, 2x, 3x)

* updated .h file for playback speed functions

* Fixed getPlaySpeed interrupt issue, added comments to new #defines

* Fixed comment
---
 Adafruit_VS1053.cpp | 17 +++++++++++++++++
 Adafruit_VS1053.h   | 14 ++++++++++++++
 2 files changed, 31 insertions(+)

diff --git a/Adafruit_VS1053.cpp b/Adafruit_VS1053.cpp
index 5ed9245..2e8b1de 100644
--- a/Adafruit_VS1053.cpp
+++ b/Adafruit_VS1053.cpp
@@ -307,6 +307,23 @@ void Adafruit_VS1053_FilePlayer::feedBuffer_noLock(void) {
   }
 }
 
+// get current playback speed. 0 or 1 indicates normal speed
+uint16_t Adafruit_VS1053_FilePlayer::getPlaySpeed() {
+  noInterrupts();
+  sciWrite(VS1053_SCI_WRAMADDR, VS1053_PARA_PLAYSPEED);
+  uint16_t speed = sciRead(VS1053_SCI_WRAM);
+  interrupts();
+  return speed;
+}
+
+// set playback speed: 0 or 1 for normal speed, 2 for 2x, 3 for 3x, etc.
+void Adafruit_VS1053_FilePlayer::setPlaySpeed(uint16_t speed) {
+  noInterrupts();
+  sciWrite(VS1053_SCI_WRAMADDR, VS1053_PARA_PLAYSPEED);
+  sciWrite(VS1053_SCI_WRAM, speed);
+  interrupts();
+}
+
 /***************************************************************/
 
 /* VS1053 'low level' interface */
diff --git a/Adafruit_VS1053.h b/Adafruit_VS1053.h
index c642c32..a74360f 100644
--- a/Adafruit_VS1053.h
+++ b/Adafruit_VS1053.h
@@ -107,6 +107,10 @@ typedef volatile RwReg PortReg; //!< Type definition/alias used to specify the
   0x0E //!< SCI_AICTRL register 2. Used to access the user's application program
 #define VS1053_SCI_AICTRL3                                                     \
   0x0F //!< SCI_AICTRL register 3. Used to access the user's application program
+#define VS1053_SCI_WRAM 0x06     //!< RAM write/read
+#define VS1053_SCI_WRAMADDR 0x07 //!< Base address for RAM write/read
+
+#define VS1053_PARA_PLAYSPEED 0x1E04 //!< 0,1 = normal speed, 2 = 2x, 3 = 3x etc
 
 #define VS1053_DATABUFFERLEN 32 //!< Length of the data buffer
 
@@ -387,6 +391,16 @@ class Adafruit_VS1053_FilePlayer : public Adafruit_VS1053 {
    * @param pause whether or not to pause playback
    */
   void pausePlaying(boolean pause);
+  /*!
+   * @brief Determine current playback speed
+   * @return Returns playback speed, i.e. 1 for 1x, 2 for 2x, 3 for 3x
+   */
+  uint16_t getPlaySpeed();
+  /*!
+   * @brief Set playback speed
+   * @param speed Set playback speed, i.e. 1 for 1x, 2 for 2x, 3 for 3x
+   */
+  void setPlaySpeed(uint16_t speed);
 
 private:
   void feedBuffer_noLock(void);