So I've just finish couple things

First of all, the Linkit connect module is working and received NTP data, I've modify the code in to a library form(Github)

and some optimization

Linkit connect module

Second, I've add a photocell which monitor environment lux to control VFD brightness, the first one just close the VFD when light is under threshold but since I connect the blink pin on MAX6921, I can control the brightness using PWM, also the control is in timer interrupt, so i don't need to constantly update value and PWM.

Third,the hardware is all finish, but to use them all ,the program size become a big problem, currently the SD lib and Wifi lib is both too big to squeeze in 28K rom, after adding NTP time sync, the code size is already 27.3K not much room for SD card,

I will try to cut down the code size by not using USB CDC(Serial),which count for 4K of ROM.

Ver 1.0 on Linkit one on the left , Ver 2.0 standalone on the right