For Grids and Segments you need to boost voltage up to 30v.

I've used MT3608 dc-dc boost converter IC for this purpose and boost 5v to 28v.

This is the Schematic of the boost circuit you can find in the datasheet :

there's several arrangement of R1 and R2 to achieve desired output voltage. this is my arrangement for maximum output voltage:

finally i choose 100K and 2.2K...