VFD watch

I've designed and made a cover for VFD watch...

Unfortunately i couldn't find a suitable connector for my purpose...So i decided to make it.

I ordered some Nokia 3110 battery connector to extract their flexible pins.These pins have the exact height that i need.

Also, I soldered M3 brass insert nuts as on-board spacer to avoid using extra screws when i'll assemble the parts

This is the controller board that has a DS3231 RTC chip , an Attiny167 microcontroller , a Buzzer and some other component...

I've designed this board for my VFD. it consists of a boost converter based on MT3608 , AC voltage provider with ATTiny13 microcontroller , ULN2803 and 74HC595 ICs to control all grids and segments with 3 pins and also has two ws2812b RGB led as backlight especially used in alarm clock feature.

I used combination of ULN2803 and 74HC595 to control all VFD just using 3 pins.

Testing boost voltage circuit with fixed output voltage also program and test Attiny13 to provide a 5v ac voltage for VFD filament.

For filament we can use DC or AC voltage but AC has superiority over DC. If the filament is driven with a DC voltage there will be a voltage gradient across its length. This means the end of the display with the more positive filament voltage will have less of a differential to the anodes, and thus will be dimmer than the negative end of the filament due to the potential gradient effect.

http://insanity4004.blogspot.com/2017/03/p170-dh-vacuum-flourescent-display.html

https://www.qsl.net/m0ayf/VFD-Regen.html

to producing AC voltage i decided to use a microcontroller, in this case i choose an Attiny13 .

for achieving a 5v 60hz ac voltage i programmed two pins of Attiny13 as output and switching them on/off respectively with a 8 milliseconds delay.

void setup() {

  pinMode(0, OUTPUT);
  pinMode(1, OUTPUT);

}

void loop() {
  digitalWrite(0, HIGH);
  digitalWrite(1, LOW);
  delay(8);
  digitalWrite(0, LOW);
  digitalWrite(1, HIGH);
  delay(8);
}

It works fine and boost 5v up to 28v