digital caliper/scale rs232 problem

[davidsgr]

Hello,
I am trying to make a terminal for controlling my Lathe and i have install 2 digital scales and i want to comunicate them with my terminal(pic 18f452) on the calipers has data and clk connections but i dont know how to communicate with the pic i am trying to connect with the serial port from my pc and nothing is happen .
If anybody has the experience to help me i will appriciate that at least to know how to use the clk pin for rs 232...!!!!
Thanks everybody read this....!!!

David


http://www.zietlowdesign.com/product...O-2_manual.htm

[johntabb]

Hi David

I don't think this is RS232.

it's probably a proprietory protocol.

I was thinking i2c but that's got SCL and SDA where the SCL pin is the clock pin, and SDA is the data pin.

Have you tried a scope on the connections to see what is there?

john

[davidsgr]

Thanks for the responce...!!!
On the databases on web says that is rs232c with 9600 or 19200 baud this is the point that i am trying to do by serial

[Les]

A quick search on Google came up with quite a few answers to your question.

http://en.wikipedia.org/wiki/Caliper#Digital_caliper


And this one has A PICmicro to convert the synchronous serial data that the calipers use to standard RS232 asynchronous data.

http://www.compendiumarcana.com/caliper/

There's more than enough information on the internet to complete your project.

[davidsgr]

on the instructions says:
working way to interface:Synchronous series
data:binary code,24bits.the cycle is 300ms
transmiting time is 0.5ms
three wires:
D data
CP clock pulse
+ positive
pulse range of data: <0.2v level "1" >1,3v
clock pulse:90khz effective for high electrical level

[davidsgr]

thanks Les but how i will send the clk??? maby is a stupid question but the serial datas for me is only

SerIn SERIALIN, 16468, [DEC3 FIRST]

how i can send the clock of 90khz???

sorry but i dont have the experience

[RGV250]

Hi David,
I do not know it this will work but you could try software SPI and just use the serial in?
The other thing is, have you had a scope on the lines to see what the data is like?
By the looks of what you have posted, you will need some sort of level shifter as well.

Regards,
Bob

[rcurl]

Take a look here: http://www.yadro.de/dro/using-interface.html

-Rick

[davidsgr]

i have the signal because i am using the LM2901 with very good resoults and i have fount some good convertion routines incide the forum but i havent the real data on lcd has anybody the idea how to make good convertion with the 48 bits of bin code?? i need bin to bcd and bcd to ascii for finalising...!!!

Device = 18F452
XTAL 20
ALL_DIGITAL = TRUE
Symbol CLK = PORTC.7
Symbol DTA = PORTC.6
LCD_DTPIN = PORTB.0
LCD_RSPIN = PORTB.4
LCD_ENPIN = PORTB.5
LCD_INTERFACE = 4 ' 4-bit Interface
LCD_LINES = 2
LCD_TYPE = 0
Dim Convert As Byte ' value to be converted from BCD to BIN or BIN to BCD
Dim Tconvert As Byte ' temp storage for the conversion process, used in both bcd_bin and bin_bcd
Dim bcd As Byte
Dim decimal As Byte
Dim VAR1 As Byte
Dim VAR2 As Byte
Dim VAR3 As Byte
Dim VAR4 As Byte
Dim VAR5 As Byte
Dim VAR6 As Byte


Cls
start:


SHIn DTA ,CLK ,msbpre , [Convert,VAR1,VAR2,VAR3,VAR4,VAR5] ' Shiftin msb-first, pre-clock.
GoSub BIN_BCD


Print At 1,1,BIN VAR4, BIN VAR5
Print At 2,1,DEC8 decimal
'Print At 1,1,"test"
GoTo start





BIN_BCD:

Tconvert = Convert//10 ' Tconvert has the remainder of the divide by 10 in the low nibble
Convert = Convert / 10 ' Convert has the integer value of the divide by 10 in the low nibble
swapf Convert,1 ' Swap the high and low nibbles of Tconvert and place result back into Tconvert
Convert = Convert ^ Tconvert ' Bitwise XOR the two results to form the BCD


decimal = Tconvert /16 *10
decimal = Tconvert // 16 + decimal
Return


Return

Include "FONT.INC"

[J. Mark Wolf]

Check out the link below. They offer DRO's (digital read outs) for Milling machines and lathes. They sell kits containing bare PCB's and PIC executables, that you can solder together yourself.


http://www.shumatech.com/web/products/dro-350