lv_font_conv --font myfont.ttf --size 24
--bpp 4 --format vlw
--range 0x20-0x7F,0x40E-0x4FF
--output myfont_24.vlw
This method gives you absolute control over kerning, compression, and symbol ranges. ttf to vlw converter
Engineers building interfaces for thermostats, medical devices, or car dashboards use LVGL. LVGL requires VLW fonts. You design your UI on a PC using a nice TTF font (like Roboto or Montserrat), then convert that TTF to VLW at specific sizes to upload to your board. lv_font_conv --font myfont
| Pitfall | Proper Fix |
|---------|-------------|
| Wrong glyph order | Must match the order of codepoints in the VLW table |
| Missing control point flattening | Recursively subdivide quadratic splines until chord deviation < 0.5 px |
| Negative y‑coordinates | VLW stores points relative to baseline (y=0 is baseline, positive up) |
| Overlapping contours (holes) | Use non‑zero winding rule; store contours in correct order |
| Integer overflow | Use int32, clamp to ±32767 (VLW's point limit per glyph) | This method gives you absolute control over kerning,
This is the standard method:
Once you have your .vlw or .h file, integrating it into your Arduino or PlatformIO project is simple.