Structured Array

I have been working on an idea for structured arrays with named elements eg
say i have a battery charger that can charge multiple batteries
each battery has these properties voltage[byte] current[word] pwm_drive[word] current_limit[word] status[byte]
thats 8 bytes per battery
;define structure batteries for pbp
struct_items con 10 ;10 index size ie number of batteries
struct_sz_of con 8 ;total 8 bytes / index

;elements byte offset of each element
volts CON 0;byte
amps CON 1;word
drive CON 3;word
climit con 5;word
stat con 7;byte
reserve our memory
battery var byte[ struct_items*struct_sz_of ]
some user commands
USERCOMMAND "ARRAY_GET" ;{array,}index,element{,var}
USERCOMMAND "ARRAY_PUT" ;index,element,DATA

we now have some nice commands ,j=byte test=word a_index=byte
array_get 2,DRIVE
array_put 2,DRIVE,1234
array_get 3,AMPS
a_index=1
array_get a_index,volts,j
array_get a_index,drive,test
even multiple arrays
array_get battery,a_index,volts,j
this is a work in progress ,whats lacking is a way to tell the usercommand the "size" of our elements as they are accessed .
at present the macros are customised to suit

I think that what you are trying to do is already done.
http://www.picbasic.co.uk/forum/showthread.php?t=3891
Look at Typcasting Variables inside of Arrays.
MyArray holds all data. And you can access them by name eg Arg0, etc.
So you could make usercommand to do this for you.

Quote:

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I think that what you are trying to do is already done.

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not really

you would need to name every element
eg bat1-drive ,bat1-current.............
bat2-drive..................
thats 50 named vars
and how can you step through them in a loop ?
my way
for i= 0 to 10
array_get i,volts,j
array_get i,amps,k
array_get i,drive,l
serout x,y,z ["in some nice format" , j, k, l,/n]
next
simple clean easy to read

How about this way?

Code:

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' ==============================================================================
'  One log record
  voltage      con    0                ' byte
  amps          CON    voltage+1      ' word (amps is 1 byte away from voltage)
  drive          CON    amps+2        ' word (drive is 2 bytes away from amps)
  climit          con    drive+2          ' word
  stat          con    climit+2        ' byte
  szLog        con    stat+1
DataLog        var    byte[szLog]  ' reserve the bytes for structure

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This takes care of your struct size and also its member offsets - akin to doing it in assembler. This is similar to what you have suggested.

Well it works. I previously had 5 arrays now everything is in one nice contiguous block ready to send to the data logger. if nothing else the code [excluding the user command bits] looks simpler and more readable.
using the

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================================================== ============================
' One log record
voltage con 0 ' byte
amps CON voltage+1 ' word (amps is 1 byte away from voltage)
drive CON amps+2 ' word (drive is 2 bytes away from amps)
climit con drive+2 ' word
stat con climit+2 ' byte
szLog con stat+1
DataLog var byte[szLog] ' reserve the bytes for structure

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method and ext var declarations is fine up until you need to have a mixed array with bytes and word vars and more than One log record that you can step through to read and write in a loop.

my method works fine but I think its only cosmetically better than in this case using 5 separate arrays.
anyway its been good practice with macros and user command

here is the demo code if your interested on a 16f1825


printout

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ready v2
fetched a word 5139
fetched a byte 24
fetched put word 1234
fetched put byte 56
array byte to any byte 8
array word to any word 3083
any array byte to any byte 44
any array word to any word 11308
array variable byte to any byte 8
array variable word to any word 3083
any array variable byte to any byte 44
any array variable word to any word 11308
Battery V A PWM
0 0 0201 0403
1 8 0A09 0C0B
2 16 1211 04D2
3 56 1A19 1C1B
4 32 2221 2423
5 40 2A29 2C2B
6 48 3231 3433
7 56 3A39 3C3B
8 64 4241 4443
9 72 4A49 4C4B

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