Hi M,See my edit. Pre coffee maths.
Mike.
No, only 32bit unsigned integer.Can Oshonsoft do 64 bit integers?
Mike.
Hi M and J,No, only 32bit unsigned integer.
Hi S,Also remember that Oshonsoft uses regular 32 bit real numbers (modified IEEE754 standard), which are accurate to only 7 digits (about).
A number like 3723.02837 would get truncated to 3723.028 as a real number, losing accuracy.
When parsing the string, the value before the decimal point should be parsed as one number, the part after the decimal (or with the decimal) as another number.
Even if parsing like 37 degrees, 23.02837 minutes, the last digit may be +/- 1 digit from real value.
You could parse the "23.02837 minutes" into a real number, as in that example, just keep in mind that the last digit may not be that significant, and ignore any change of +/- 1 digit (ie: consider 7 to 8 as "no change"). I think that even 6 digits would be accurate enough. Not sure what happens if minutes is less than 10, does it insert a leading zero (I think it would)Hi S,
'When parsing the string, the value before the decimal point should be parsed as one number, the part after the decimal (or with the decimal) as another number.'
So using this method, we could get good accuracy, is this correct?
If this is correct we will need to take care of stepping over the spot where the last digit before the decimal point clocks over.
Anyway, we'll all be repeating this when testing the machinery, so best save it till then.
C
Hi S,You could parse the "23.02837 minutes" into a real number, as in that example, just keep in mind that the last digit may not be that significant, and ignore any change of +/- 1 digit (ie: consider 7 to 8 as "no change"). I think that even 6 digits would be accurate enough. Not sure what happens if minutes is less than 10, does it insert a leading zero (I think it would)
What do you do about the degrees and the hemisphere? This is why I suggested converting to a 32 fractional value where zero and 0.99999999999 (0xffffffff) would be the range as 1 is the same as zero.You could parse the "23.02837 minutes" into a real number
I found a sentence with 5109.0262239 as a coord so the zero must accompany the 9 at 510° wouldn't make sense.Not sure what happens if minutes is less than 10, does it insert a leading zero (I think it would)
Hi M,What do you do about the degrees and the hemisphere? This is why I suggested converting to a 32 fractional value where zero and 0.99999999999 (0xffffffff) would be the range as 1 is the same as zero.
I found a sentence with 5109.0262239 as a coord so the zero must accompany the 9 at 510° wouldn't make sense.
Mike.
That confuses things, why isn't -1.417 W, 1.417 E.----------------------N------W
Mid UK------------ 52.623,-1.417
Yup, as it needs to be or connect one of them to Vcc.The 'shift register' has 2x DATA pins, I have connected them, as the tests, is this ok?
That can be connected to a spare pin if you like, at the moment the shift register is cleared in the for loop that sets up the servo times.EDIT: There is a reset
LATC.0=0 'ensure data is low
LATC.2=0 'and clock
For i = 0 to 7
LATC.2=1 'send positive clock edge
servoPos(i)=i*250+2000 '1ms(2000) to 1.875(1 7/8ths - 3750)ms in 1/8th mS steps
LATC.2=0 'send negative edge
Next iHi M,That confuses things, why isn't -1.417 W, 1.417 E.
The thing about GPS coordinates is the longitude is always great circles and split like segments of an orange but the latitude is only a great circle at the equator and gradually gets smaller until it's zero at the poles (bet that's caused a few bugs). Makes any calculations "interesting".
A difference of 1° E/W is a different length dependent on how far N/S you are.
Mike.
Hi M,Yup, as it needs to be or connect one of them to Vcc.
That can be connected to a spare pin if you like, at the moment the shift register is cleared in the for loop that sets up the servo times.
This should execute very fast and clear all outputs of the shift register (hopefully before the servos have completed there power on setup time). The reset pin should be tied high in this case. An alternative is to use a capacitor resistor reset circuit.Code:LATC.0=0 'ensure data is low LATC.2=0 'and clock For i = 0 to 7 LATC.2=1 'send positive clock edge servoPos(i)=i*250+2000 '1ms(2000) to 1.875(1 7/8ths - 3750)ms in 1/8th mS steps LATC.2=0 'send negative edge Next i
Mike.
I realize this and question why have the hemisphere at all? We don't need E and S at all!!!North of the equator is '+' so no sign
South of the equator is '-' so has '-' sign
East of Greenwich and West of the Date line is '+' so no sign
West of Greenwhich and East of the Date line is '-' So has a '-' sign.
Yup, all good.Hi M,
The above is not clear.
I would like the fewest tracks I need to add, as long as it works.
At the moment, it is working. The reset is tied high.
The 2x DATA pins are tied together and go to RC0
The CLK goes to RC2.
If this is ok, then good.
C
Hi M,Yup, all good.
BTW, why does the number of tracks matter?
Mike.
Hi M,The ISR controls the servos and receives a sentence from the GPS. The background program (at the moment) is just moving the servos to demonstrate that it's all working. The background program (in the while loop) can be replaced by the parsing code and then move the servos to where they need to be. Once the sentence is parsed the isDone bit should be cleared so it (the ISR) can receive another sentence.
So, it seems to me that next is adding the parse code to the servo code.
Mike.
mean SERVO parse CODE?So, it seems to me that next is adding the parse code to the servo code.
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