Sending a word variable from an 08m2 to a 28x2. Help please?

Hello there,
I've already trawled through other forum posts and the picaxe manuals but I can't find anything simple enough for my simple brain to understand.
All I want to do is send w1 and w2 from the 08m2 to the 28x2, I have tried to start with the serout and serin commands but I am not sure how to use them in tandem.
Any help will be much appreciated

Joe

Assuming you are looking at a hard wired (not wireless) connection then the requirements are simple:
1. Wiring - a wire from the desired output pin of the 08M2 to the desired input pin of the 28X2.
Also connect the Gnd/0V lines of both PICAXE chips together if not on the same supply.
2. Some lines of code.
(A) for Tx side - sending the low and high byte of each word variable separately
SEROUT <pin>, baudrate, (b2,b3,b4,b5)
(B) For the Rx end
SERIN <pin>, baudrate, b2,b3,b4,b5 ; note no brackets

For <pin> see PICAXE manual1 pages 9 to 11 to ascertain which pins can be inputs and/or outputs on each chip.
For baudrate suggest start with N2400 and adjust later once your code is working

I've got them both on the PICAXE project board, all I want it to do now for test purposes is to light up an LED when the variable is correct.
How do I change the word variables into byte variables, am trying to send w1 = 24328.

A word variable consists of two consecutive byte variables. From manual 2, page 10

However for larger numbers two byte variables can be combined to create a word
variable, which is capable of storing integer numbers between 0 and 65535
inclusive. These word variables are labelled w0, w1, w2 etc... and are constructed
as follows:
w0 = b1 : b0
w1 = b3 : b2
w2 = b5 : b4
w3 = b7 : b6
etc...

Click to expand...

Byte variable maximum value is 255, so you need to use word only if the value stored exceeds this.

So your W1 is actually b3:b2

This is what i have written now, still not getting something right.

the top one is for the o8m2 and the bottom one is for the 28 x2

start:
b3:b2 = 24328
high c.2
if pinc.3 != 1 then : goto start : endif
serout c.1, N2400, (b3,b2)
goto start

start:
pause 50
if pinb.6 != 1 then : goto start : endif
high b.7
pause 50
serin b.5, N2400, b3, b2
if b3:b2 = 24328 then : high b.4 : endif
low b.7
pause 1000
low b.4
goto start

Oarsome said:

This is what i have written now, still not getting something right.

Click to expand...

So what actually happens ?

I expect...

b3:b2 = 24328
^

Error: Syntax error in this line!

...although w1 is comprised of b3 and b2, you can't use that notation in the code

So use " w1 = 24328 " instead.

with: " w1 = 24328 "

b2 automatically holds the low byte and b3 holds the high byte of the word value.

in effect:
b3 = 24328 / 256

b2 = 24328 // 256 which is the equivalent of b2 = 24328 - (b3 * 256)

if i put this program in i get the flashing led.
08m2
start:
b0 = 50
high c.2
if pinc.3 != 1 then : goto start : endif
serout c.1, N2400, (b0)
goto start

28x2
start:
pause 50
if pinb.6 != 1 then : goto start : endif
high b.7
pause 50
serin b.5, N2400, b0
if b0 = 50 then : high b.4 : endif
low b.7
pause 1000
low b.4
b0 = 0
goto start



If i put this one in i get nothing.

08m2
start:
w0 = 24328
high c.2
if pinc.3 != 1 then : goto start : endif
serout c.1, N2400, (w0)
goto start


28x2
start:
pause 50
if pinb.6 != 1 then : goto start : endif
high b.7
pause 24328
serin b.5, N2400, w0
if w0 = 24328 then : high b.4 : endif
low b.7
pause 1000
low b.4
w0 = 0
goto start

One trick for easily handling the msb and lsb bytes is to define them via SYMBOL definitions; for example w1 is made up from b3 (MSB) and b2 (LSB) so ...

At the receiving end ...

I still don't understand what I am doing wrong

symbol value = w1
symbol value.lsb = b2
symbol value.msb = b3

start:
value = 24328
high c.2
if pinc.3 != 1 then : goto start : endif
serout c.1, N2400, (value.lsb, value.msb)
goto start




symbol value = w1
symbol value.lsb = b2
symbol value.msb = b3

start:
pause 50
if pinb.6 != 1 then : goto start : endif
high b.7
pause 24328
serin b.5, N2400, value.lsb, value.msb
if value = 24328 then : high b.4 : endif
low b.7
pause 1000
low b.4
value = 0
goto start

i just noticed the pause 24328 in there, ive taken it out now and now it works yay!!! Thank you everyone for your input