Add hardware horizontal scrolling functionality

examples/scrolling/CMakeLists.txt

@@ -0,0 +1,19 @@
+cmake_minimum_required(VERSION 3.13)
+
+include(pico_sdk_import.cmake)
+
+project(scrolling_example)
+
+pico_sdk_init()
+
+add_subdirectory(pico-ssd1306)
+
+add_executable(scrolling_example
+        main.cpp)
+
+target_link_libraries(scrolling_example
+        hardware_i2c
+        pico_ssd1306)
+
+
+pico_add_extra_outputs(scrolling_example)

examples/scrolling/main.cpp

@@ -0,0 +1,43 @@
+#include "pico/stdlib.h"
+#include "pico-ssd1306/ssd1306.h"
+#include "pico-ssd1306/textRenderer/TextRenderer.h"
+#include "hardware/i2c.h"
+
+// Use the namespace for convenience
+using namespace pico_ssd1306;
+
+int main(){
+    // Init i2c0 controller
+    i2c_init(i2c0, 1000000);
+    // Set up pins 12 and 13
+    gpio_set_function(12, GPIO_FUNC_I2C);
+    gpio_set_function(13, GPIO_FUNC_I2C);
+    gpio_pull_up(12);
+    gpio_pull_up(13);
+
+    // If you don't do anything before initializing a display pi pico is too fast and starts sending
+    // commands before the screen controller had time to set itself up, so we add an artificial delay for
+    // ssd1306 to set itself up
+    sleep_ms(250);
+
+    // Create a new display object at address 0x3D and size of 128x64
+    SSD1306 display = SSD1306(i2c0, 0x3D, Size::W128xH64);
+
+    // Here we rotate the display by 180 degrees, so that it's not upside down from my perspective
+    // If your screen is upside down try setting it to 1 or 0
+    display.setOrientation(0);
+
+    drawText(&display, font_12x16, "Hello", 12, 0);
+    drawText(&display, font_12x16, "World!", 48, 16);
+    // Send buffer to the display
+    display.sendBuffer();
+
+    while (true) {
+        display.setHorizontalScroll(ScrollDirection::Left, true, 0, 7, 0x00); // scroll left
+        sleep_ms(6500);
+        display.setHorizontalScroll(ScrollDirection::Right, true, 0, 7, 0x00); // scroll right
+        sleep_ms(6500);
+        display.setHorizontalScroll(ScrollDirection::Left, false); // turn scrolling off
+        sleep_ms(5000);
+    }
+}

examples/scrolling/readme.md

@@ -0,0 +1,7 @@
+# This examples produces such a result
+
+![output](output.gif)
+
+## Notes
+
+Utilizes the hardware scrolling commands for SSD1306. See data sheet for more info.

ssd1306.cpp

@@ -20,42 +20,42 @@ namespace pico_ssd1306 {
 
         // this is a list of setup commands for the display
         uint8_t setup[] = {
-                SSD1306_DISPLAY_OFF,
-                SSD1306_LOWCOLUMN,
-                SSD1306_HIGHCOLUMN,
-                SSD1306_STARTLINE,
+            SSD1306_DISPLAY_OFF,
+            SSD1306_LOWCOLUMN,
+            SSD1306_HIGHCOLUMN,
+            SSD1306_STARTLINE,
 
-                SSD1306_MEMORYMODE,
-                SSD1306_MEMORYMODE_HORZONTAL,
+            SSD1306_MEMORYMODE,
+            SSD1306_MEMORYMODE_HORZONTAL,
 
-                SSD1306_CONTRAST,
-                0xFF,
+            SSD1306_CONTRAST,
+            0xFF,
 
-                SSD1306_INVERTED_OFF,
+            SSD1306_INVERTED_OFF,
 
-                SSD1306_MULTIPLEX,
-                63,
+            SSD1306_MULTIPLEX,
+            63,
 
-                SSD1306_DISPLAYOFFSET,
-                0x00,
+            SSD1306_DISPLAYOFFSET,
+            0x00,
 
-                SSD1306_DISPLAYCLOCKDIV,
-                0x80,
+            SSD1306_DISPLAYCLOCKDIV,
+            0x80,
 
-                SSD1306_PRECHARGE,
-                0x22,
+            SSD1306_PRECHARGE,
+            0x22,
 
-                SSD1306_COMPINS,
-                0x12,
+            SSD1306_COMPINS,
+            0x12,
 
-                SSD1306_VCOMDETECT,
-                0x40,
+            SSD1306_VCOMDETECT,
+            0x40,
 
-                SSD1306_CHARGEPUMP,
-                0x14,
+            SSD1306_CHARGEPUMP,
+            0x14,
 
-                SSD1306_DISPLAYALL_ON_RESUME,
-                SSD1306_DISPLAY_ON
+            SSD1306_DISPLAYALL_ON_RESUME,
+            SSD1306_DISPLAY_ON
         };
 
         // send each one of the setup commands
@@ -166,7 +166,6 @@ namespace pico_ssd1306 {
         i2c_write_blocking(this->i2CInst, this->address, data, 2, false);
     }
 
-
     void SSD1306::setContrast(unsigned char contrast) {
         this->cmd(SSD1306_CONTRAST);
         this->cmd(contrast);
@@ -184,4 +183,26 @@ namespace pico_ssd1306 {
         this->cmd(SSD1306_DISPLAY_ON);
     }
 
+    bool SSD1306::setHorizontalScroll(ScrollDirection scrollDirection, bool shouldScroll, uint8_t startPage, uint8_t endPage, uint8_t timeInterval) {
+        uint8_t scrollCommand = (scrollDirection == ScrollDirection::Left) ? SSD1306_HORIZ_SCROLL_LEFT : SSD1306_HORIZ_SCROLL_RIGHT;
+
+        if (startPage > 7 || endPage > 7 || endPage < startPage || timeInterval > 0x07) return false;
+
+        uint8_t commands[] = {
+            scrollCommand,
+            0x00, // dummy byte
+            startPage, // start page 0
+            timeInterval, // time interval
+            endPage, // end page
+            0x00, // dummy byte
+            0xFF, // dummy byte
+            static_cast<uint8_t>(SSD1306_SET_SCROLL | (shouldScroll ? 1 : 0)) // Start/stop scrolling
+        };
+
+        for (uint8_t &command: commands) {
+            this->cmd(command);
+        }
+
+        return true;
+    }
 }

ssd1306.h

@@ -37,6 +37,9 @@ namespace pico_ssd1306 {
         SSD1306_CHARGEPUMP = 0x8D,
         SSD1306_EXTERNALVCC = 0x1,
         SSD1306_SWITCHCAPVCC = 0x2,
+        SSD1306_HORIZ_SCROLL_RIGHT = 0x26,
+        SSD1306_HORIZ_SCROLL_LEFT = 0x27,
+        SSD1306_SET_SCROLL = 0x2E
     };
 
     /// \enum pico_ssd1306::Size
@@ -48,7 +51,7 @@ namespace pico_ssd1306 {
     };
 
     /// \enum pico_ssd1306::WriteMode
-    enum class WriteMode : const unsigned char{
+    enum class WriteMode : const unsigned char {
         /// sets pixel on regardless of its state
         ADD = 0,
         /// sets pixel off regardless of its state
@@ -57,6 +60,12 @@ namespace pico_ssd1306 {
         INVERT = 2,
     };
 
+    /// \enum pico_ssd1306::ScrollDirection
+    enum class ScrollDirection : const unsigned char {
+        Left,
+        Right
+    };
+
     /// \class SSD1306 ssd1306.h "pico-ssd1306/ssd1306.h"
     /// \brief SSD1306 class represents i2c connection to display
     class SSD1306 {
@@ -127,8 +136,17 @@ namespace pico_ssd1306 {
 
         /// \brief Turns display on
         void turnOn();
-    };
 
+        /// \brief Enables or disables scrolling
+        /// \param scrollDirection - direction of scrolling. Left or right
+        /// \param shouldScroll - true to enable scrolling, false to disable scrolling
+        /// \param startPage - page to start scrolling from. Valid values are 0 to 7
+        /// \param endPage - page to end scrolling at. Valid values are 0 to 7 and must be greater than or equal to startPage
+        /// \param timeInterval - time interval between each scroll step. Accepted values 0x00 to 0x07
+        /// \return true if parameters are valid and scrolling was set, false if parameters were invalid
+        bool setHorizontalScroll(ScrollDirection scrollDirection, bool shouldScroll = true, uint8_t startPage = 0,
+                                 uint8_t endPage = 7,uint8_t timeInterval = 0x00);
+    };
 }
 
-#endif //SSD1306_SSD1306_H
+#endif //SSD1306_SSD1306_H