LED vintage watch on a breadboard with AT90S8535 and DS1302
Design "for fun", vintage watch à la 90s, made on a contact plate. A gadget perfect for the shelf. :)
I had an AT90S8535 controller in stock, and since I recently returned to programming, I decided to use it for something useful. The once exorbitant 8 kB of flash on board is rather different from today`s standards, and it is so slow that uploading a 4 kB program takes almost 6 minutes using the USBASP programmer.
The construction is quite standard. The controller`s task is to get/set the time from the RTC clock (DS1302) and control the multiplexed display. The control is based on a timer that generates an interrupt every 1 ms with an 8 MHz quartz. The interrupt procedure turns off and on the next segment and keeps the light on for 200 µs. The main loop deals with data retrieval, button and beeper control.
Basically, I made the project as a training and reminder of AVR programming in C, while the assembly on a breadboard involves a bit of modeling to make it work and look good. :)
The watch has found a place of honor on the shelf and does its job - it shows the time.
I had an AT90S8535 controller in stock, and since I recently returned to programming, I decided to use it for something useful. The once exorbitant 8 kB of flash on board is rather different from today`s standards, and it is so slow that uploading a 4 kB program takes almost 6 minutes using the USBASP programmer.
The construction is quite standard. The controller`s task is to get/set the time from the RTC clock (DS1302) and control the multiplexed display. The control is based on a timer that generates an interrupt every 1 ms with an 8 MHz quartz. The interrupt procedure turns off and on the next segment and keeps the light on for 200 µs. The main loop deals with data retrieval, button and beeper control.
Basically, I made the project as a training and reminder of AVR programming in C, while the assembly on a breadboard involves a bit of modeling to make it work and look good. :)
The watch has found a place of honor on the shelf and does its job - it shows the time.
Comments
Add a commentI wonder how long this watch will work without failure on the contact board. Congratulations on installing this system :) [Read more]
In the 1990s, contact sheets were not used, they used universal ones. [Read more]
Nevertheless, it would be better to solder it even on a universal machine, and if it is "vintage", add some period elements if they are to be visible, e.g. this DS would look nice here: https://ob... [Read more]
If electronics can look nice, it`s probably in this form. These colorful cables seem to be doing the job here. Just three things. It would be necessary to lay these cables from the transistors to the... [Read more]
I personally like it on the breadboard and respect it for cramming it onto the breadboard :) It is aesthetically made, that`s the most important thing. Write to me at Paczkomat and I will send you a small... [Read more]
The atmosphere is there, at least when it comes to appearance. But like other colleagues here, I have some concerns about the reliability of structures using this technology in the long term. Therefore,... [Read more]
@u2244896 what is the deviation from the synchronized time over a month/year? From what I remember, the ISP programmer on LPT did not take so long to load these programs. [Read more]
It hasn`t worked for that long, but it has already made a difference of a few seconds, so it`s probably not the most accurate, but it`s still pleasing to the eye. [Read more]
Where does somebody obtain the code to operate the -- AT90S8535 -- in this clock mode? And... what does it take to program the AT90S8535 so it works like the breadboard does? If I were to build this,... [Read more]