I have a mindstorms nxt compass that I am trying to interface to my picaxe(18x) but when I do I get random values that dont change when I turn it. I have verified the wireing is correct. It was working at one point but now it is not. Did I fry it? I am using the example code provided with PE. Any Ideas. Thanks.
NXT Compass
- Thread starter D396
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If it was working and now isn't then something has gone wrong or changed, perhaps you have fried it but it could be something else. The supplied example code is written for the 20X2 so perhaps post your full circuit and the code you have modified for use with the 18X.
Have you tested if the 18X works with other I2C devices ?
Here is the code
Ill post the circuit in a minute.
Code:
' Hitechnic NXT Compass Sensor (part MS1034)
symbol heading_2degree = b0
symbol heading_adder = b1
symbol heading = w1
' Wires on NXT jack plug.
' Wire colours may vary. Pin 1 is always end nearest latch.
' 1 White No connect
' 2 Black 0V
' 3 Red 0V
' 4 Green V+ (4.5V or 5V)
' 5 Yellow SCL
' 6 Blue SDA
' Do not use i2c pullup resistor - already provided within sensor.
init:
'Slave address is $02
hi2csetup i2cmaster $02, i2cslow, i2cbyte
'Optional configuration
hi2cout $41,($00) ; normal mode
'hi2cout $41,($43) ; hard iron calibrate mode
pause 100
main:
; read values
hi2cin $42,(heading_2degree) ', heading_adder
heading = heading_2degree * 2 '+ heading_adder
; debug display
debug
; wait 1 second then loop
pause 1000
goto main
A proper schematic would help, or at least remove wires and components which don't connect to anything or aren't used. The problem with photos is that they don't show everything; power supply, reset pull-up.
What power supply are you using ? If batteries it may be worthwhile trying with a fresh set.
Quite probably. At least that would be a fair bet if I were placing money on it.