IV-3, IV-6 VFD 6 digit clock Shield for Arduino

Details

Tested only with IV6-tubes

AXIRIS IV-3 Shield for Arduino is super great project, specially power supply is very good designed. etc. filament is driven with AC voltage which is recommended for VFD. 12V input voltage is 3x multipled to make 36V I am redesigned board for easier soldering, all components are in lines with same value

added buttons for HOUR / MINUTES
speaker driver for make alarm clock, in current firmware is only hour beep implemented
components values on PCB
DS3231 with battery backup
Enhanced to 6 DIGIT
hand painted curved traces for more retro look
all outputs are marked on pcb for better debugging
schematic is almost unchanged, some pins are swapped for better PCB routing

I created simple CLOCK arduino sketch (firmware)

IV-3

IV-6

IV-3 vs IV-6

Backlit just parallel connected LED

Little updated new layout.

Large batch PCB ORDER LINK http://dirtypcbs.com/store/designer/browse/bobricius

Required parts list IV‐3/IV-3a/IV-6 shield for Arduino (BOM )

1/4W subminiature carbon THT resistors

Pcs	value	Description
1	510 Ω	Ø1.8x3.2mm
2	1K	Ø1.8x3.2mm , tube light, optional
1	2K7	Ø1.8x3.2mm
1	3K9	Ø1.8x3.2mm
14	10K	Ø1.8x3.2mm
14	68K	Ø1.8x3.2mm
14	100K	Ø1.8x3.2mm
14	220K	Ø1.8x3.2mm

CERAMIC/MKT /MKM CAPACITORS

Pcs	value	Description
1	2.2 nF	-
1	100 nF	-
2	8.2 nF !!!	I am replaced with 100nF

ELECTROLYTIC CAPACITORS

Pcs	value	Description
4	22 µF 50V	-
2	100 µF 25V	-

DISCRETE SEMICONDUCTORS

Pcs	value	Description
1	1N400x	rectifier diode
4	1N5819	schottky diode
6	LED 3mm	Tube bottom light optional (choose color freely) , optional
14	BC547B	NPN transistor
14	BC557B	PNP transistor
1	BC639	NPN “power” transistor
1	BC640	PNP “power” transistor

INTEGRATED CIRCUITS

Pcs	value	Description
1	ICM7555	timer IC (must be CMOS version, do not use a standard 555 !)
1	DS3231	RTC chip , optional

CONNECTORS & OTHER PARTS

Pcs	value	Description
1	Arduino UNO	or clone
28	header	spacing 2.54 mm
1	CR1220	Lithium battery , optional
1	CR1220 socket	Battery holder , optional
6	tube	IV‐3/IV-3a/IV-6 VFD tube
2	switch	angled, Microswitch TACT
1	Piezo 17mm	buzzer, optional

If you want original board go here >

https://www.elektor.com/iv-3-vfd-shield-for-arduino-kit-150064-71

https://www.axiris.eu/en/index.php/project-corner/iv-3-shield-for-arduino

Files

board.png

Portable Network Graphics (PNG) - 127.86 kB - 01/05/2021 at 00:16

Preview

schematic.png

Portable Network Graphics (PNG) - 75.72 kB - 01/05/2021 at 00:16

Preview

SimpleCLock6.zip

Arduino code

x-zip-compressed - 5.86 kB - 07/21/2020 at 21:58

Download

Project Logs

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Discussions

TomasOlah wrote 02/08/2026 at 10:00

Ahoj, otazka. Neskusal si miesto mcu pripojit to na TM1638 a cez i2c na MCU (s vyuzitim iba 6 tubes)?

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bobricius wrote 02/08/2026 at 14:38

Ahoj TM1638 je na LED, VFD su vysokonapetove srandy tam sa pouziva MAX6921, ano skusal som, fungovalo to pekne (hladaj od Adafruit Ice Tube Clock), nepripadalo mi to dostatocne cool ani retro :)

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TomasOlah wrote 02/10/2026 at 08:58

Diky, moj napad vychadzal z ciela minimalizovat pocet datovych vodicov z MCU pouzitim i2c (rad pouzivam wemos d1 mini), podpora v TASMOTA fw. Podla popisu ty pouzivas Arduino UNO. Inac velmi sa mi paci tvoja praca na ArmaChat (sam fungujem na MeshCore).

Mas este nejake zlte PCB k tomuto projektu, co predavas na na Tindie? Ma by som zaujem o 1ks. Dakujem.

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bobricius wrote 02/10/2026 at 12:48

diky;) Uz aj ja prechadzam na MeshCore https://youtu.be/gHOvBLMxgOw vsetky plosaky sa minuli jediine cez pcbway alebo mam este taku verziu co je nalezato

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TomasOlah wrote 02/10/2026 at 13:37

aky je rozmer dosky FLAT? vyzera to, ze tam staci IV-6 postavit.

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bobricius wrote 02/10/2026 at 20:17

10x10cm

Are you sure? yes | no

marty7932 wrote 03/03/2025 at 20:01

Ahoj, byly by na.prodej jeste nejake DPSka IV6? Dekuju ti

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bobricius wrote 03/03/2025 at 20:59

https://www.tindie.com/products/19338/ ciste plosaky ale ked chces mam aj take 90% osadene

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Benoit Tourret wrote 07/07/2023 at 14:46

Six month than my clock is working 24/7.

The only issue I got was a short circuit with the USB connector housing, I burnt one transistor. replaced easily. I removed the metal shield of the USB plug.

Could a wifi+ntp version could work with the Arduino Uno R4 wifi ?

There is 3 weeks of delay, but I could compile the original sketch without any errors or warning...

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tstaff.lx wrote 05/28/2023 at 13:04

can someone tell me what voltage the 100nf capacitor are supposed to be.

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Benoit Tourret wrote 07/07/2023 at 14:50

it is a ceramic capacitor with will never see over 12V.

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Jakub wrote 06/02/2021 at 13:29

Ahoj jsem tu nový potřeboval bych poradit teprv se učím programovat ještě nic jsem neprogramoval na arduino Uno programuji tyto hodiny jenže mi to hlásí chybu nejde nahrát vůbec mám arduino Uno klon a arduino program nevím jestli se to dá nebo ne párovat díky. Jsem úplný zelenáč.

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rezite wrote 04/26/2021 at 18:44

Ahoj chtěl bych se zeptat zdali budou tyto hodiny fungovat i s trubicemi IV-11? děkuji

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bobricius wrote 05/23/2021 at 19:22

musis si skontrolovat pinout a rozmery, potom poprehadzovat nozicky

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Ian Sparkes wrote 11/16/2020 at 07:39

I can't find the schematic anywhere. I'm trying to figure out what you mean by "filaments driven by AC"? Are you really inverting the filament drive or just pulsing a single ended filament supply?

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bobricius wrote 01/05/2021 at 00:16

it is look like really inverted voltage. Including schematic in FILES

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Alin Marin Elena wrote 11/14/2020 at 21:27

so, finally got the time to put all the components together. is the 6 iv-6 board.

Since I do not plan to use the switches I did not install them also nothing from what is marked as optional. unfortunately things do not seem to work all i get are the base leds flashing.

now to debug I would like to understand something

- are the 1k and the led need? the ones on top of the buzzer.

- can I get away without the switches?

- shall the underside vin 36 or 12 be connected?

any other suggestion would be appreciated.

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Climber20 wrote 07/26/2020 at 06:06

You have the Arduino Code with support for ds3231 RTC?

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bobricius wrote 09/08/2020 at 11:28

yes, DS3231 is supported and code is in files

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Jamie wrote 04/26/2020 at 17:51

Hi, I am new to electronics and have bought some IV-3 tubes to try to make a clock with. Would using your PCB and listed components be beginner friendly or do you recommend starting somewhere else? Thanks.

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bobricius wrote 07/19/2020 at 21:39

There is about 130 component to solder and more than 300 solder points, I am not sure if it is for beginner.

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Ian Shannon Weber wrote 03/14/2020 at 05:05

I hope your project continues to do well.

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IV-3, IV-6 VFD 6 digit clock Shield for Arduino

Details

Large batch PCB ORDER LINK http://dirtypcbs.com/store/designer/browse/bobricius

Required parts list IV‐3/IV-3a/IV-6 shield for Arduino (BOM )