Whats sitting on your workbench today?

Hi Matt,

Thanks for the nice post about your project. Today I am playing with a cheap Chinese Clock kit and trying to decide if it will be able to be modified and used in future projects. I am really glad that you have been checking the e14 website as your robot is exactly the type of project that will interest a lot of our members. I hope you post more about it and more detail.

John

Hi Matt,

Thanks for the nice post about your project. Today I am playing with a cheap Chinese Clock kit and trying to decide if it will be able to be modified and used in future projects. I am really glad that you have been checking the e14 website as your robot is exactly the type of project that will interest a lot of our members. I hope you post more about it and more detail.

John

Hi John! thanks for getting involved, What does this cheap chinese clock kit involve?  Do you have any pictures or product links that could inspire any of our members!

Thank you for your interest in Zed, the previous version of my robot came runners up in the  Ben Heck PiTop comp at the end of last year, you can see my entry under the highlights tap one the page https://www.element14.com/community/docs/DOC-83528/l/win-ben-hecks-raspberry-pi-top-laptop

he had wheels back then!

Hi Matt,

Here is the clock kit that you asked about:

https://www.banggood.com/DIY-4-Digit-LED-Electronic-Clock-Kit-Temperature-Light-Control-Version-p-972289.html?rmmds=myorder

I was experimenting with different clocks to see how they could be modified to be used in some of the makeshift test equipment I like to build from time to time. Here are a couple pictures of the completed clock.

After building it I thought I was having some trouble with Key Bounce and since I had just read a nice post about key debounce circuits:

https://www.element14.com/community/community/project14/diytestequipment/blog/2017/08/12/vintage-555-a-general-purpose-button-debouncer

by: balearicdynamics

I decided to add a little extra debounce to the circuit. I pulled one of the digits back off the board so I could get at the switches.

Then I added the two 10 nF caps across the switches.

The bounce problem was probably just my imagination as I can't believe that the programmer of the micro processor didn't debounce the switches with software but now we have made sure.

The construction of the circuit went very well and the unit worked though I had a bit of difficulty understanding a function on the clock that the Chinese author of the instructions called Now Time. Turns out he was referring to a feature where the clock beeps on the hours between two specified time limits.

John

Hi John, thank you for citing !

Why did not solder the caps to the opposite side ? It seems that now the last digit is a couple of mm hight than the others. Or it is a optical illusion?

Enrico

Hi Enrico,

The structure of the support brackets of the switches themselves prohibited mounting on the switch side of the board. Fortunately the Display segments sit up on legs that provide 4 or 5 mm of clearance underneath. The small ceramic 10 nF fit nicely under the display and the fronts of the displays are flush with each other. Thanks again for your great post and I see that the in depth discussion of bounce it continuing over there. Awesome!

John

Thank you John,

not always is easy to understand from the images

BTW, respect the Chinese designers, I don't like so much components hidden under other components ...

Enrico