void screens::mainMenu(uint8_t menu_id){
    u8g.firstPage();
    do {
        reset(); // start from fresh screen.
        drawTitleBox("MODE SELECTION");
        u8g.setColorIndex(WHITE);
        u8g.drawBox(0, 10*menu_id+12, u8g.getWidth(), 10);

        u8g.setColorIndex(menu_id == 0 ? BLACK : WHITE);
        u8g.setPrintPos(5,10*0+12);
        u8g.print("AUTO SEARCH");
        u8g.setColorIndex(menu_id == 1 ? BLACK : WHITE);
        u8g.setPrintPos(5,10*1+12);
        u8g.print("BAND SCANNER");
        u8g.setColorIndex(menu_id == 2 ? BLACK : WHITE);
        u8g.setPrintPos(5,10*2+12);
        u8g.print("MANUAL MODE");

#ifdef USE_DIVERSITY
        u8g.setColorIndex(menu_id == 3 ? BLACK : WHITE);
        u8g.setPrintPos(5,10*3+12);
        u8g.print("DIVERSITY");
#endif
        u8g.setColorIndex(menu_id == 4 ? BLACK : WHITE);
        u8g.setPrintPos(5,10*4+12);
        u8g.print("SAVE SETUP");
    } while( u8g.nextPage() );
}
void screens::drawTitleBox(const char *title) {
    u8g.setColorIndex(WHITE);
    u8g.drawFrame(0, 0, u8g.getWidth(), u8g.getHeight());
    u8g.drawBox(0, 0, u8g.getWidth(), 11);
    u8g.setColorIndex(BLACK);

    // center text
    u8g.setPrintPos(((u8g.getWidth() - u8g.getStrWidth(title)) / 2),1);
    u8g.print(title);
}