"SILENT" MULTI ALARM REMINDER GADGET

sedeap

Senior Member
"silent" Multi Alarm Reminder Gadget

Here is the thing:

I need build some gadget-gizmo to do....
Silent reminders at certain hours.
So here the explanation.
Need one Smallest piece of artwork, so the clock must be "blind" (no display at all) and when say "silent" remind mean vibrating alarm plus flash led.
I really have available now two AXE08 and the vibrator device from one smashed old cellphone who works great with 5v.
Tons of resistors, diodes and capacitors available too, one LM7805.
This gadget can be powered by two "CR2032 - 3V lithium button cell" or anything alike.
It must remind 7 or more alarm events each day.
Everyday work, with same fix reminders.

Why this?...
Because I want to make it for an old friend of mine (Univ. Professor) who has one and was thefted from her house some time ago.
Her gadget looks like an Thick Fountain Pen or a fashion Pendrive With a Laser Pointer in one end.

Now one factory in USA make some same-use device but look like one BIG OLD BEEPER With Belt clip.
Link=> <External Web Link>
named "invisible clock" at U$s 40.-

She ask me "can you make for me some like that?"
and I say "Yeah... how difficult can be?"
YES, I've a BIG mouth!... so I'm in troubles now...

The problem with buy one Inv.clock standard is the fact of that is "ugly2 Unconfy and big for one "mature lady" who Never ever use Pants or belts, only Dresses & Skirts...
She "use to" keep the old gizmo in hand like Pointer Standard when in Class teaching or making an Speech.

So...
->clock module for PICAXe => "Discarded"
(Anyway NEVER come here, only AXE chips, nor modules or kits) Yeah! our Unique RE-Distributor Sucks!
->Internal "timer" not good accuracy for "week cycle" => "Rejected"
->... ... ... ...

Any Ideas?

:)s)
 
Last edited:

beny1949

Senior Member
really to get any kind of long term accuracy you really will need a clock module like the ds1307, which is quite well documented by rev-ed. the only problem is that this uses i2c; this not avaliable on a 8 pin picaxe.

i dont know if anyone has got a way of bitbanging i2c?

the only way that doesnt need the old i2c that i can think of is to use some kind of ocilator circuit, to make a pulse which will increment a counter in the picaxe? not sure it would be very accurate



 
 

hippy

Technical Support
Staff member
Bit-banged I2C is possible with a PICAXE-08, and certainly with an 08M because it does need a reasonable amount of code space. It should be quite easy to use two 08's, one handling I2C, the other doing alarm matching and vibration triggering.

An external hardware oscillator and counter should be as accurate as the DS1307 is. That could use a 32kHz watch or normal/canned 4MHz crystal with a bigger divider. Any frequency really can do the job, but it may make the software a little bit more involved.

Looking at the 08, 08M and 14M it doesn't look possible to use Timer1 in external 32kHz crystal mode, although it <i>may </i> be possible to bang an incrementing pulse in through /T1G. Timer0 is probably tied to the watchdog, so that's probably not an option.

With the 18X it should be possible to use a 32kHz watch crystal to drive Timer1 directly once the Outputs have been re-configured as inputs by poking the required shadow SFR, and of course an 18X supports I2C so a DS1307 is easy to interface.

My feeling is that an 08 with external crystal and divider would be better than using I2C and a DS1307 to save code space, an 08M would be okay with a DS1307, and an 18X with a direct 32kHz crystal would be worth a try.
 

hippy

Technical Support
Staff member
Having said all that ... using a PIACXE-08 run a program which sets up the DS1307 via I2C to have it output a pulse once a second on its SQW line, then the 'main program' when downloaded only needs to look for that one second pulse, that doesn't need to use I2C at all whiel runing.
 

sedeap

Senior Member
Thanks all Pal's

So hippy, you put me to thinking one &quot;hybrid&quot; solution...
I think... I probabily can mix technologies, one for &quot;clock ticking&quot; and AXE to management, so I only must Hack an old but working &quot;watch-pen&quot; core with one single daily alarm reminder and &quot;chime&quot; hourly function, this maybe (IF God let me) can be used to keep running accurately the AXE schedule... The alarm triggering the Start Point at fixed Hour(eg: 8:00) every day, and the short &quot;chime&quot; output can mark the rhythm (like an Heart beat) so the AXE can keep the counts...
Some years ago, y build one PLC for a factory, and use similar solution... but that time, I use a mechanical clock timer.
So, only must find a solution for interfacing the mini-watch trough the Piezo buzzer they have...

Any have another Idea ?

:0)

Edited by - sedeap on 02/06/2007 06:46:21

Edited by - sedeap on 02/06/2007 06:47:38
 

sedeap

Senior Member
WOW !
I do it !
The only thing what need review is the container.
But I can make a new one with some cheap pen flashligh or cigar cannister.
When I beat the task, I upload some pics.
Thanks Pal's for the Support and advise.

:eek:)
 
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