more flexible, slight sanity fixes

include/LCDDisplay.hpp

@@ -1,6 +1,9 @@
 #ifndef LCDDISPLAY_HPP
 #define LCDDISPLAY_HPP
 
+#define LCD_LINES 4
+#define LCD_COLS 40
+
 #include <array>
 #include <cstdint>
 #include <sstream>
@@ -9,29 +12,30 @@
 class LCDDisplay {
    private:
     uint8_t _lcd;
-    char writebuf[4 * 40 + 8];                          // 4x40 chars + 2x4 setcursor commands
+    char writebuf[LCD_LINES * LCD_COLS + 8];                       // 4x40 chars + 2x4 setcursor commands
-    void writeStr(std::string str);                     // do not use
+    static constexpr bool dualDisp = (LCD_LINES * LCD_COLS > 80);  // is it dual display device or not, evauluated from the size at compile time
-    void writeLines(std::array<std::string, 4> lines);  // do not use
+    void writeLines(std::array<std::string, 4> lines);             // do not use
 
    public:
     LCDDisplay(std::string dev, uint32_t baud = 0010002);  // from termios-baud.h, B115200
     ~LCDDisplay();
 
-    // custom char array
-    char cc[8] = {'\0', '\1', '\2', '\3', '\4', '\5', '\6', '\7'};
-
     void clear();
-
     void setContrast(uint8_t contrast);
     void setBacklight(bool enabled);
     void setBacklight(uint8_t brightness);
     void setCursor(uint8_t row, uint8_t col);
     void setCustomChar(uint8_t index, std::array<uint8_t, 8> cchar);
 
+    void writeStr(std::string str);
+    void writeStr(uint8_t row, uint8_t col, std::string str);
     void writeBuf(uint8_t row, uint8_t col, std::string str);
     void clearBuf();
     void flushBuf();
 
+    // returns custom char no. c, small enough to define in header
+    constexpr char cc(uint8_t c) { return c % 8; }
+
     char bar(uint8_t char_id, double value);
 };
 

src/LCDDisplay.cpp

@@ -28,7 +28,16 @@ LCDDisplay::LCDDisplay(std::string dev, uint32_t baud) {
     tcflush(lcd, TCIFLUSH);
     tcsetattr(lcd, TCSANOW, &term);
     _lcd = lcd;
-    clearBuf();  // init linebuf to spaces
+
+    // init linebuf to spaces
+    clearBuf();
+
+    // disable underline and block cursor
+    uint8_t cmdbuf[] = {254, 75, 254, 84};
+    write(_lcd, &cmdbuf, 4);
+
+    // clear display and set cursor home
+    clear();
 }
 
 LCDDisplay::~LCDDisplay() {
@@ -53,11 +62,11 @@ void LCDDisplay::setBacklight(bool enabled) {
     write(_lcd, &cmdbuf, enabled ? 3 : 2);
 }
 
-/* doesnt quite work yet, need to look up matrix orbital spec */
+/* still doesnt work? */
 void LCDDisplay::setBacklight(uint8_t brightness) {
     std::println("[LCDDisplay::setBacklight] Set backlight brightness to {}", brightness);
-    uint8_t cmdbuf[] = {254, (uint8_t)(brightness ? 66 : 70), brightness};
+    uint8_t cmdbuf[] = {254, (uint8_t)(brightness ? 66 : 70), 255, brightness}; // 3rd char is timer, 4th is brightness
-    write(_lcd, &cmdbuf, brightness ? 3 : 2);
+    write(_lcd, &cmdbuf, brightness ? 4 : 2);
 }
 
 void LCDDisplay::setCursor(uint8_t row, uint8_t col) {
@@ -72,44 +81,50 @@ void LCDDisplay::setCustomChar(uint8_t index, std::array<uint8_t, 8> cchar) {
     write(_lcd, &cmdbuf, 11);
 }
 
+/* immediately writes string to the lcd at current cursor pos */
 void LCDDisplay::writeStr(std::string str) {
     write(_lcd, str.c_str(), str.size());
 }
 
+/* immediately writes string to the lcd at given cursor pos */
+void LCDDisplay::writeStr(uint8_t row, uint8_t col, std::string str) {
+    setCursor(row, col);
+    writeStr(str);
+}
+
 void LCDDisplay::writeLines(std::array<std::string, 4> lines) {
     for (auto& line : lines) {
-        if (line.size() > 40) {
+        if (line.size() > LCD_COLS) {
             std::println("[LCDDisplay::writeLines] Line {} too long! ({} chars)", line, line.size());
             continue;
         }
-        line.insert(line.end(), 40 - line.size(), ' ');
+        line.insert(line.end(), LCD_COLS - line.size(), ' ');
     }
 
-    setCursor(0, 0);
+    writeStr(0, 0, lines[0] + lines[1]);
-    writeStr(lines[0] + lines[1]);
+    writeStr(2, 0, lines[2] + lines[3]);
-    setCursor(2, 0);
-    writeStr(lines[2] + lines[3]);
 }
 
 /* writes string to write buffer at calculated pos */
 void LCDDisplay::writeBuf(uint8_t row, uint8_t col, std::string str) {
     size_t len = std::min(str.size(), sizeof(writebuf) - col);
-    uint8_t pos = 4 + col + (40 * (row % 2));  // skip 4 bytes to leave room for set cursor command
+    uint8_t pos = 4 + col + (LCD_COLS * (row % 2));  // skip 4 bytes to leave room for set cursor command
-    if (row >= 2) pos += 84;                   // if we're writing to disp2, skip another 4 bytes for set cursor command and 2*40 bytes of disp 1
+    if (row >= 2) pos += 2 * LCD_COLS + 4;           // if we're writing to disp2, skip another 4 bytes for set cursor command and 2*40 bytes of disp 1
     std::memcpy(&writebuf[pos], str.c_str(), len);
 }
 
+/* initializes the write buffer to spaces */
 void LCDDisplay::clearBuf() {
     std::memset(writebuf, ' ', sizeof(writebuf));
 }
 
-/* hyper optimized buffer flush command, writes whole disp with a single write */
+/* flushes writebuffer to lcd, hyperoptmized, flushes buffer and commands in a single write operation */
 void LCDDisplay::flushBuf() {
     // we could skip all of this and set it in constructor if we were extra sure the lines wont ever exceed 40 chars
     constexpr uint8_t setDisp[] = {254, 71, 1, 1};  // set cursor to char 1, line 1
     std::memcpy(&writebuf[0], setDisp, 4);
-    std::memcpy(&writebuf[84], setDisp, 4);
+    std::memcpy(&writebuf[2 * LCD_COLS + 4], setDisp, 4);
-    writebuf[87] = 3;  // overwrite set cursor c1 l1 to c1 l3
+    writebuf[2 * LCD_COLS + 7] = 3;  // overwrite set cursor c1 l1 to c1 l3
 
     write(_lcd, writebuf, sizeof(writebuf));
 }
@@ -120,5 +135,5 @@ char LCDDisplay::bar(uint8_t char_id, double value) {
     for (uint8_t i = 0; i < (1.0 - value) * 8; i++)
         b[i] = 0;
     setCustomChar(char_id, b);
-    return cc[char_id];
+    return cc(char_id);
 }