16F628 thermometer

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Working on that George,

I just migrated the whole code to an 18F4525 to see if I could actually do it..

Its working minus the DS18S20. and I think its the driver code.

One quick question for you George,

Did you create your own digits or use a manufactured one.

Reason I ask is the code as it sits has no room for a negative sign, My solution at this point is if your made your own digits as I did, then using the DP (dot) from the left digit can become your negative symbol. just series 2 or 3 led's with resistor and you can at least have the hardware ready.
 


Mike,

You saying this project could be changed to 2 chips to drive all 8 displays instead of 1 chip on each digit?
 
clock/thermometer

Hi Stevey
Yes I made my own displey 7 1/2 -4 1/2 with 2 rows of 7 LED for each segment. The DP (dot) can be use for displey"C" at the end for celsius or "-" in front for negativ,
Thanks George
 
Good to know George

I've made some changes with assistance of others to get the 10th degree resolution so 10.8°c etc, with the ° and c shifted to the right digit, this means your ° pin will become pin 15 on the last TPIC5B595 and the DOT decimal place will be on the TPI second from the LEFT, both of these lines can be connected to the ° line as they will only ever be seen at the same time. So we can be lazy on that and let the °C and . appear with the same command

BTW the new code is for a a ds18B20 sensor

I used 4 led's in series to create each segment on my display, so a 3 led series with resistor will be created to become the - negative symbol and it will be driven from either Pin_A1 or Pin_A4 in a similar fashion to the colon's OR be shifted in on the LEFT digit using it's DP (Pin 6 on its TPI chip)

So far its all code with just 3 led's and 3 new wires needed to make the changes.

The only draw back I see at this point is the negative symbol may look out of place with just single value negatives - 5.2°c as the left most digit will be blank.

Coding to make seg G of the left digit can be done then shift it to the DP seg if a 10 value is present but that will take a bit longer

Should be done soon.
 
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Hi Steve,

Yes, you can multiplex your 8 digit display using two chips (but more I/O lines)... Or you could use three chips and four I/O lines... Multiplexing requires moving the display driver into an Interrupt Service Routine which may sound intimidating but is actually simpler than the example driver I sent you awhile back... It also allows you to drive much larger matrices like the one pictured below with just a half dozen chips...

Have fun... Mike
 

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Ye the 2 chip method.

Larger pics at my disposal, 18F4525 or 4620

Languages

Pic C
or
ProBasic

I'm learning both atm.
 
Hi SteveyD

I am still attempting to get this circuit working... I am using the three LED version (KingBright SA23-11GA LEDs) and still have had no luck getting it to do much of anything. Occasionally when I apply power a segment will light in the first LED but thats the most it ever does. I have tried all the suggestions in your posts and still no luck. Do you have any idea if the 3 digit version will work? Have you tried it on Proteus? I have checked my wiring again and programmed the 628 with all fuses off except for XT...

thanks
 
I've not found a TPIC6B5959n model yet to try on Proteus

that 3 digit unit may cause problems because the right 2 digits are configured "normal" and the left 2 digits are upside-down. The MAP characters are different for the two sets of digits.

Double check and make sure CP (copy protection is OFF as well when you write to the chip.

It took me quite a while, 3 months to get it to work, now that I've got it running, I'm poking my way through the code, cleaning it up as best I can and I will post a more detailed project for this with proper respect to the Sixca project.

I'm hoping to have it completed within the next few days.
 
Clock/temp

Hi.
I make this project digital clock and thermometer, too.
Make on some veroboards, connecting wires point to point with -4 indicators from Kingbright SA56-11EWA at 595 driver's outputs, with some little changes. In future interesting make this project with bigger digits.
1. In place of BC557, put 2 n-p-n BC547 transistors, which inverted pulse of seconds and when I see temperature on display, seconds dot is off,
2. I am not a programist, but have interest. Thanks, to find both clock_temp628.hex and clock_temp628.c, made some code comparision ,calculate, write right code in .hex file ,that changes little " c " to bigger" C " on indicator. Looks better!
But I have similar interest to view "-" temperatures, about this read in topics earlier . For example for better view of negative temperature sign, may be "-"sign may to placeded in non standard place as: " 'C - " .Because the 4-th indicator is off anyway and have free " G " SEGMENT?
If is posibility to make that changes or have any good ideas ,answered, please
From programms, I have only MPLAB IDE, not any C compiliers
Regards, Janis
 



Mike, I finally have some time to give the multiplexing a try. Let me know if you have time as well.

Cheers
Steve
 
Hi. Back with good news.
Find much more info how this project developed in another forum, that very helps to continue with mine model.
For minus temperatures measuring added another very similar part as in "show temperature". Temperature represents without tenth, with "-" sign on the left digit and little "c" from A,F,G segments on the right digit. When flashing, with: high=1000, low=500 , it looks very good.
And remove zero hours from left display , too. For example at night clock earlier shows 0230, but after changes showed time is 230 .
Don't like, how works push buttons for clock time setup. Need more delays.
Regards, Janis
 
Hi...

I am trying to build this circuit to understand and practice pic programming.

This is not my first project, but I am getting troubles to finish it.

I can compile in CSS the source without problem, but for test, I am using the hex file from site.

I am only testing the circuit with a few changes in design, try to see something with only two displays before go ahead! I am planning to add second digits.

These are the pictures...

- When the circuit is turn on, we can see the local temperature, blinking. It means that PIC and Temperature sensor are working fine:

Image 1

- After a few seconds. the displays are with "zeros", no change to temperature! This is the last state.

Image 2

Someone can help me?

Thanks!!
 
Hi.
In a source file you can see diferent time's for showing temperature and for showing clock.
"zeros"in your displays indicated hours and OK, I think.
Clock indicators show time longer than temperature indicators.
Hex file on the net is fully workable.
Regards Janis
 
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Hi!
I am using the hex from the site, without changes...
When the displays show "zeros", stay with "zeros" forever...
It´s like something is not running... But I don´t what is... I´ve tryed with two RTCs, still the same...
Must be some connection requiredo....
 
Hi!
I build this project mostly on the vector board and digits wired with resistors at first. But to this moment that model is partly damaged.
Second maded on vectorboard, too i put in the case and to this time it's far from away.
If I remember true , after powering up this project at first time, may be stay on clock mode with blinking minute digits.
For editing you need to connect setting buttons to your PIC chip pins. After you seting the time, you can start your clock.
With 3V backup battery the clock starts normaly.
Regards, Janis
 
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