diff --git a/include/LCDDisplay.hpp b/include/LCDDisplay.hpp index 5179a5c..2f3a45c 100644 --- a/include/LCDDisplay.hpp +++ b/include/LCDDisplay.hpp @@ -9,7 +9,7 @@ class LCDDisplay { private: uint8_t _lcd; - char linebuf[4][40]; + char writebuf[168]; // 4x40 chars + 2x4 setcursor commands void writeStr(std::string str); // do not use void writeLines(std::array lines); // do not use diff --git a/src/LCDDisplay.cpp b/src/LCDDisplay.cpp index aacc557..6f89200 100644 --- a/src/LCDDisplay.cpp +++ b/src/LCDDisplay.cpp @@ -60,7 +60,6 @@ void LCDDisplay::setBacklight(uint8_t brightness) { write(_lcd, &cmdbuf, brightness ? 3 : 2); } - void LCDDisplay::setCursor(uint8_t row, uint8_t col) { uint8_t cmdbuf[] = {254, 71, (uint8_t)(col + 1), (uint8_t)(row + 1)}; write(_lcd, &cmdbuf, 4); @@ -92,28 +91,25 @@ void LCDDisplay::writeLines(std::array lines) { writeStr(lines[2] + lines[3]); } -/* writes string to line buffer at given pos*/ +/* 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(linebuf[row]) - col); - std::memcpy(&linebuf[row][col], str.c_str(), len); // will overflow + 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 + 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 + std::memcpy(&writebuf[pos], str.c_str(), len); } void LCDDisplay::clearBuf() { - std::memset(linebuf, ' ', sizeof(linebuf)); + std::memset(writebuf, ' ', sizeof(writebuf)); } /* hyper optimized buffer flush command, writes whole disp with a single write */ void LCDDisplay::flushBuf() { - uint8_t writebuf[168]; // 4x40 chars + 2x4 setcursor commands + // we could skip all of this and set it in constructor if we were extra sure the lines wont ever exceed 40 chars uint8_t setDisp[] = {254, 71, 1, 1}; // set cursor to char 1, line 1 - - std::memcpy(&writebuf[0], setDisp, 4); // copy set cursor command - std::memcpy(&writebuf[4], linebuf[0], 40); // copy 1st line - std::memcpy(&writebuf[44], linebuf[1], 40); // copy 2nd line - std::memcpy(&writebuf[84], setDisp, 3); // copy set cursor command but skip the line byte - writebuf[87] = 3; // set cursor to 3rd line - std::memcpy(&writebuf[88], linebuf[2], 40); // copy 3rd line - std::memcpy(&writebuf[128], linebuf[3], 40); // copy 4th line + std::memcpy(&writebuf[0], setDisp, 4); + std::memcpy(&writebuf[84], setDisp, 4); + writebuf[87] = 3; // overwrite set cursor c1 l1 to c1 l3 write(_lcd, writebuf, 168); }