# Can CD40110 start counting from 1

#### delini

Joined Jan 22, 2023
5
I have a small assignment to made a century clock (which include year, month, day, hour, minute, second) without using micro-controller. I decide using CD40110 to driving common cathode 7-seg LED directly instead of using 2 separate IC ( 1 counter such as 74LS90 and 1 driver such as 74247). I have some problems when deadling with year-month-day. I attach my pic of schematic circuit for month only below.

How can I start counting from 1 instead of 0 in CD40110? I've tried to connect my logic reset to clock-up so when it reset, It will have a pulse to clock to display 1 directly but it's fail.

If CD40110 can't do it, do you guys recommend more feasible solutions? Thank you.

#### dl324

Joined Mar 30, 2015
15,511
Welcome to AAC!
I have a small assignment
Does that mean this is school work?

Your schematic is one of the cleanest Proteus schematics I've seen. It would be better if you printed in black and white and so we don't have to look at that grid and that awful background.

#### sghioto

Joined Dec 31, 2017
3,952
If you mean starting at "1" on power up you can try this solution.

#### delini

Joined Jan 22, 2023
5
Does that mean this is school work?
Not really, I'm 19 and trying to dive into digital electronic and I find this project in a course online. So I try to stimutale one clock myself

Your schematic is one of the cleanest Proteus schematics I've seen. It would be better if you printed in black and white and so we don't have to look at that grid and that awful background.
Oh, thank you for recommendation, I'm totally new and has much things to learn. I will print it next time

#### delini

Joined Jan 22, 2023
5
If you mean starting at "1" on power up you can try this solution.
View attachment 285811
I mean starting at "1" on every time CD40110 reset (which is seted by the logic AND and OR, in my case is 12). My English is not good, I mean I expect that It will run like: 11 -> 12 -> 1 -> 2 .... (instead of 12 -> 0 -> 1 ...)

#### delini

Joined Jan 22, 2023
5
12 -> 0 -> 1 ...
Here that my circuit current behavior. I want it start from 1 after 12.

#### dl324

Joined Mar 30, 2015
15,511
Not really, I'm 19 and trying to dive into digital electronic and I find this project in a course online. So I try to stimutale one clock myself
That would be a typical age for someone to enter college.
I mean I expect that It will run like: 11 -> 12 -> 1 -> 2 .... (instead of 12 -> 0 -> 1 ...)
Unfortunately, the counter you selected doesn't have preset capability.

You'll have to use a different counter and use a BCD to 7 segment decoder to drive the display.

#### dl324

Joined Mar 30, 2015
15,511
Here's a synchronous 1-12 counter I designed using JK flip flops.

The hex to 7 segment decoder was done with logic gates. As was the binary to BCD converter.

#### dl324

Joined Mar 30, 2015
15,511
Here's a 1-12 counter using 74LS192

Since TTL is harder to get these days, you could also use CD4510, CD4029, or any other presettable up counter. The former are both up/down counters.

#### MrSalts

Joined Apr 2, 2020
2,767
Use a CD4027 - it has preset inputs.

#### delini

Joined Jan 22, 2023
5
Here's a 1-12 counter using 74LS192
View attachment 285909
Since TTL is harder to get these days, you could also use CD4510, CD4029, or any other presettable up counter. The former are both up/down counters.
Thank you so much for your help, I completed the clock

#### dl324

Joined Mar 30, 2015
15,511
Thank you so much for your help, I completed the clock
Congrats. Care to post a schematic?

If you're interested in learning how to design synchronous counters using flip flops, as in post #8, I can help you. The hex to 7 segment converter I used can be implemented with a ROM; that's how the commercial parts were implemented. I chose to use logic just for the practice. I breadboarded something similar in the late 70's when I was a technician. The binary to BCD converter is a common school problem that uses the double dabble algorithm.

The logic simulator I use is free.
EDIT: insert 'I' above.

Last edited:

#### MrSalts

Joined Apr 2, 2020
2,767
Thank you so much for your help, I completed the clock