using a RTC in SF basic

[MrDEB]

I have a DS-1302 RTC module but how to use it?
I recall Jon Chandler made a vu meter clock but what he used for timing?
Am planning on a clock that has no hands, just LEDs but precision would be nice.

 

[MrDEB]

am using

RQ5E040AJTCL mosfet

I think Easyeda has the wrong? symbol in their schematic

 

[MrDEB]

My error when I flipped the mosfet over in the schematic.

 

[MrDEB]

I think maybe I can flip the Mosfet over, flatten out the legs, then solder to the board?
I think this might work.
I have new boards being shipped, so will unsolder the MOSFETs and check this out before using a new board

 

[MrDEB]

Flipping the MOSFET won't work' Need a SOT23 footprint.
researching using an NPN transistor. Want something that will mount directly or will need to CA glue the Mosfets and hardwire?
Beau Schwabe is using NPN transistors as well (post #105)

 

[MrDEB]

I located an NPN transistor that should work?

https://www.taydaelectronics.com/datasheets/files/A-3192.PDF

ANY better suggestions?

 

[For The Popcorn]

I don't see how, since the pinout is basically the same. Perhaps reading replies to your posts would have avoided this problem?

 

[MrDEB]

I made corrections to the circuit design and contemplating ordering some new boards.

 

[For The Popcorn]

Which would be version 3?

 

[MrDEB]

YES version 3
I will bite the bullit on new boards AFTER I recheck everything etc.

 

[MrDEB]

After reviewing post#122 etc am contemplating going with multiple boards.
Curious why use the 74hc595 instead of the cd4017?

 

[ChrisP58]

After reviewing post#122 etc am contemplating going with multiple boards.
Curious why use the 74hc595 instead of the cd4017?

The two are completely different devices.
The 74hc595 is a shift register with output latches.
The cd4017 is a counter with 10 decoded outputs.

 

[be80be]

He probably meant the CD4021

 

[MrDEB]

This is where I am headed for a clock design using CD4017.
I'm not done with it, but it's where I am headed.
Thinking of connecting ALL the minute cd4017 RESET inputs together?

 

[For The Popcorn]

This is where I am headed for a clock design using CD4017.

I really, really feel compelled to ask.....

Why do you mention Beau S 's circuit that is simple, straightforward, demonstrated to work AND allows you to display any pattern you want on the LEDs, then decide to create your own fakata circuit that if it does what you expect (it won't – what's the source/sink current of the CD4017?) will allow you to show exactly two LEDs at a time in a fixed pattern?

Your copy&paste™ technique may work (poorly) for software, but it gets expensive quickly when applied to hardware.

 

[MrDEB]

One big reason is simplicity. Never worked with the 74hc595.
My plan is to use porta.(x) as the clock input to the cd4017. Sounds simple??
Going to order some cd4017 and breadboard the proposed circuit.
Yes I need to calculate current draw etc.

 

[MrDEB]

I am trying to get this done before the %60 tariffs on products from China'
Ordered 10-cd4017's
Have several 555's on hand

 

[For The Popcorn]

My plan is to use porta.(x) as the clock input to the cd4017. Sounds simple??

No. It sounds dumb. Stupid in fact. Destined to failure. With a 5 volt supply, the CD4017 can source or sink ONE (1) mA.

But do as you please. You seem to like making scrap boards.

 

[MrDEB]

I Need to do more research.
500me dissipation
10ma per output.
Plan on ONLY 2 OR LESS LEDS ON AT ONE TIME

 

[ChrisP58]

One, and only one, of the ten outputs from the CD4017 will always be on.

So, one LED of the 1_10 group will be on. and one of the 11_20 group will be on, and so on for all of the ten led groups feed from a CD4017.

 

[For The Popcorn]

One, and only one, of the ten outputs from the CD4017 will always be on.

So, one LED of the 1_10 group will be on. and one of the 11_20 group will be on, and so on for all of the ten led groups feed from a CD4017.

I'm thinking he only wants one LED for minutes and one for hours although his current scribblematic won't accomplish that.