Multi-digit word variable to string

[Amoque]

Good morning.

I have recently resurrected an old project as a means of introducing myself to PBP3 and the PIC16F88. It is a scrolling marquee on a single 5x7 matrix LED; the characters are 5x5 and with some missteps, I am now able to display a static message quite satisfactorily. Yaye me!

To extend my knowledge, I determined to interface an LM34 temperature sensor as demonstrated here: http://www.rentron.com/PicBasic/LM34.htm. The project calls for a PIC16F677--the ADC setup is different, but therein lays the learning. Armed with the datasheet, I went to work… a reasonable period later, I felt I had adequate understanding to program some code.

While I may (or may not) have gotten the ADC configured properly, the real frustration is displaying the result! I had intended to use the [DEC] statement, [DIG], and some division to insert each digit into the string array for display, but [DEC RawT (the word variable holding the ADC result)] results in a “Bad expression” error. I had thought perhaps that my ADC result was indecipherable, but even setting RawT to a likely value does not change the result.

TL;DR:
Can someone with a better understanding demonstrate how a multi-digit word variable be converted to a single digit string format; i.e. RawT=754 --> MSG[x]= “7”, MSG[x+1]= “5”, MSG[x+2]= “4”? Also, seeing that I’ve impinged on your good nature already, can you verify my ADC configuration to read from AN0 on pin17, using a +Vref on AN3 (pin 2)?

Many thanks...

CONFIG:
#CONFIG
__config _CONFIG1, _INTRC_IO & _WDT_OFF & _PWRTE_OFF & _MCLR_ON & _BODEN_OFF & _LVP_OFF & _CPD_OFF & _WRT_PROTECT_OFF & _DEBUG_OFF
__config _CONFIG2, _FCMEN_OFF & _IESO_OFF
#ENDCONFIG
DEFINE OSC 8
OSCCON = %01110000
ANSEL = %00001001 'ANALOG OFF, EXCEPT +Vref AND AN3
TRISA = %0001001 'PORTS TO MATCH ANSEL
ADCON1.7 = 0 : ADCON1.6 = 0 : ADCON1.5 = 1 : ADCON1.4 = 0 'LEFT JUSTIFIED : ADCS2 DISABLED : VCFG Vref+ AVSS
ADCON0 = %01011001 'Fosc/8 : AN3 ACTIVE : ADON (BIT0) ADC ON
TRISB=0 'PORTB DIGITAL

[HenrikOlsson]

Hi,
One way could be to use the ArrayWrite command, something like:

MSG VAR BYTE[4]
RawT VAR BYTE

RawT = 754

ARRAYWRITE MSG, [DEC RawT]

/Henrik.

[Amoque]

Thank you, Henrik.
I love when the answer is shorter than the question!

To be clear then, it appears that DEC is not a command of itself, but a parameter of some other display functions; it is only valid in an output string to an LCD or other output device (ie serial port) or construct (array-obviously).

I hope it is not too much trouble for any who follow this thread to correct my interpretation as well as to clarify one more point? Can an entry point be specified, as ARRAYWRITE MSG[14], [DEC RawT] so that the variable may be positioned in a larger array? I saw little on this when searching

It is possible to specify an entrypoint, so that (for example) the string "Temperature = XXX degrees" can be dynamically updated with Arraywrite ARRAYNAME[entrypoint] = [DEC variable]

[HenrikOlsson]

Hi,
That's correct. DEC is not a command by itself, it's what the manual calls a modifier among others (BIN, HEX etc).

I've never tried it but I'm pretty sure you can start anywhere in the array in the way you show.

/Henrik.

[astanapane]

Hello all,

this is an old post. I'm not sure if my question fits right to here.

I have a temperature values and i would like to send them to a display from 4D Systems.

At the moment i was using the serial SPE commands as 4D Systems calls it, and they have exactly the command to send those variables.

Then i tried their "new" Visi Genie enviroment, which allows you to create "forms" and add any image, button etc.

I have fniished the easy task inside the Visi Genie and i'm in front of a problem that i need to transform the variable to string.

As from 4D Systems:

Visie-Genie writes to pre-defined objects so in this case it is a pre-defined string object so all we have to do is convert what we need to send to a string, calculate a checksum and send. This is where Genie differs from Serial as in the Serial mode you are sending a serial command to the display which is translated to a command to do a supported function on the display.

It is the first time i had to do a task with Checksum and found it interesting way by XORing all the bytes. In a very small code i tryied it worked, as i sent based on 4D Systems the command to change the constrast and it worked.

command var byte
constrast var byte
CS var byte

' -----------------------------------------------------------------------------|
' [ LCD Initialization ] |
'------------------------------------------------------------------------------|
' FIRST TIME BOOTUP: We give plenty of time for tbe LCD '
lcdinit:
pause 2000
command = $04
contrast = $06
gosub checksum
hserout [command,contrast,CS]
hserin [wait(6)]
pause 100


high green
return

'------------------------------------------------------------------------------|
' CHECKSUM |
'------------------------------------------------------------------------------|
checksum:
cs = 0
cs = cs ^command
cs = cs ^ contrast
return

Now i'm trying to see the way to convert var to string. I have read the manual written in 2013

"A numeric value preceded by a pound sign ( # ) will send the ASCII representation of its decimal value, up to 65535. For example, if W0 = 123, then #W0 (or #123) will send "1", "2", "3"."

Is that the right way? May i have your help please?

[Ioannis]

Or use DEC modifier like DEC k. If k=5, DEC k will send out the "5".

With DEC you can also specify how many digits you will send. E.g. DEC3 will send 3 digit of the variable with the appropriate leading zeros in this case to fit the number of digits requested.

If k=15 then DEC3 k will send "0", "1", "5"

Ioannis

[richard]

i have had three or four people say i'm not a good teacher,
i'm not surprised since i never have been or ever aspired to be one

so what do think of my new signature ?

Warning I'm not a teacher , one on one Tuition with flowery prose like a gushing embroilment is not my style

[astanapane]

Richard,

i may need to apologize for my behaviour as well. I do not expect that from you.

Do what you know better to do, in this particular field. Everyone has its bad and good days. We are all in the same boat.

You never know one day, i may be some how useful for you.....

Take care and try to smile.

[richard]

out of curiosity i downloaded the real data sheet and discovered quite a few things


1 the bus speed is 100khz
2 the datasheet depicts an abnormally long repeated start signal on a read transaction [no specs but]
3 the bus needs a SMBus Request signal before a read/write transaction
4 the genuine article has addr 0 not 0xb4

looking at ebay banggood aliexpress etc yields a 5 to 1 price range from $10 to nearly $60 us
most venders spruking a multitude of part numbers in the listing, you would wonder what you are buying
i suspect clones fakes and lookalikes abound

a real one from e14 or rs is $40ish au , a bit much for a play trinket for me
so i don't think i can take it much further