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I wear one made of aluminum foil...Tin hat on
Because of this both bits in question are "1" when not pressed. So they will invert to "0".Code:IF (GPIO.3=1) AND (GPIO.4=1) THEN
If the thing was not sleeping that is.
But wait...
They are "0"...Code:DAT_OUT = %10101001
What if one of the buttons are pressed?
In the end, all eight bits of DAT_OUT are sent.
Yes, I am being a cryptic smart _ _ _.
Dave
Always wear safety glasses while programming.
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Spoken like a true engineer, even uses a ground plane as a hatI wear one made of aluminum foil...
Well I know what I'll be doing tonight.... uncryptifying!Yes, I am being a cryptic smart _ _ _
Dave
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It's looking like I'm going to need someone to hold my hand and gently walk me through this one as I'm confusing myself: Here's my latest piece of reasoning / thinking.....
Right then:
This is the data BYTE to be sent.
Bruce says:Code:DAT_OUT = %10101001
So at the moment they're 0 - 0.Only DAT_OUT bits 1 and 2 are used.
So I'm going to leap in here and say that from the code below DAT_OUT.0[1] (bit one of the BYTE) will be equal to the inverted state of GPIO.3 (the program only gets to this piece of code after a button press though).
And DAT_OUT.0[2] (bit two of the BYTE) will be equal to the inverted state of GPIO.4Code:DAT_OUT.0[1]=~GPIO.3
So taking SW1 as the button being pressed: GPIO.3 which was '1' when not pressed goes to '0' when pressed then gets inverted ~ to a '1' which becomes bit one of the BYTE.Code:DAT_OUT.0[2]=~GPIO.4
How does that sound? North of the North pole? South of the South South pole? Or under the ice at either pole?
Dave
Last edited by LEDave; - 17th November 2010 at 18:22.
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I'm going to need someone to hold my hand
Yup, you got it!So taking SW1 as the button being pressed: GPIO.3 which was '1' when not pressed goes to '0' when pressed then gets inverted ~ to a '1' which becomes bit one of the BYTE.
Dave
Always wear safety glasses while programming.
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Well metaphorically speaking, I was beginning to panic figuring the code out.I'm going to need someone to hold my hand
So am I right in thinking that the DAT_OUT byte:
Becomes:Code:DAT_OUT = %10101001
When SW1 is pressed.Code:DAT_OUT = %10101011
And
When SW2 is pressed.Code:DAT_OUT = %10101101
The checksum:
Will that always be the calculated value of BYTE:Code:' Build checksum of 2 data bytes CHK_SUM = (DAT_OUT * 2)
Because this is the last BYTE to be read / run in the program sequence.Code:DAT_OUT.0[2]=~GPIO.4
Dave
Last edited by LEDave; - 17th November 2010 at 22:43.
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Yes, you have all of that correct.So am I right in thinking that the DAT_OUT byte:
CHECKSUM..
We are dealing with BITs here.Because this is the last BYTE to be read / run in the program sequence.
Back to what you have above that either BIT#1 or BIT#2 will be changed when a switch is pressed, DAT_OUT will be eitherCode:DAT_OUT.0[1]=~GPIO.3 'BIT #1 of DAT_OUT DAT_OUT.0[2]=~GPIO.4 'BIT #2 of DAT_OUT
%10101011
or
%10101101
So...
CHK_SUM = (DAT_OUT * 2)
Will be
CHK_SUM = (%10101011 * 2)
or
CHK_SUM = (%10101101 * 2)
Dave
Always wear safety glasses while programming.
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We are dealing with BITs here.
The penny has finally dropped
So the checksum is made up of:
Cheers mackrackit, I need a lie down, I expect you do too:Code:DAT_OUT = %10101001 Plus the BIT that has changed *2
I don't know how you put up with me sometimes.
Dave
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