Instrument control package: Difference between revisions
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m (Add mandatory parameter "lang", avoid error category https://www.mediawiki.org/wiki/Extension:SyntaxHighlight#lang.) |
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! i2c | ! i2c | ||
| bgcolor="green" | v0.1.0 || - || - || bgcolor="skyblue" | stalled || - | | bgcolor="green" | v0.1.0 || - || - || bgcolor="skyblue" | stalled || - | ||
|- | |||
! spi | |||
| bgcolor="green" | v0.6.0 || - || - || - || - | |||
|- | |- | ||
! TCP | ! TCP | ||
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{{Code|Check for interface support|<syntaxhighlight lang="octave" style="font-size:13px"> | {{Code|Check for interface support|<syntaxhighlight lang="octave" style="font-size:13px"> | ||
pkg load instrument-control | pkg load instrument-control | ||
supportedinterfaces = instrhwinfo().SupportedInterfaces | |||
if ( | if ! isempty(strfind (supportedinterfaces , "serial")) | ||
disp("Serial: Supported") | disp("Serial: Supported") | ||
else | else | ||
| Line 48: | Line 52: | ||
#similarly with: | #similarly with: | ||
# | # ! isempty(strfind (supportedinterfaces , "parallel")) | ||
# | # ! isempty(strfind (supportedinterfaces , "i2c")) | ||
</syntaxhighlight>}} | </syntaxhighlight>}} | ||
| Line 360: | Line 364: | ||
== i2c == | == i2c == | ||
i2c | Example with a Si7021 i2c breakout board (https://www.sparkfun.com/products/1376) connected to a i2c master interface. | ||
To work out the devices available (assuming i2ctools are installed) run the i2cdetect command from a terminal window. | |||
<syntaxhighlight lang="bash" style="font-size:13px"> | |||
$ i2cdetect -l | |||
i2c-1 i2c i2c-ch341-usb at bus 002 device 008 I2C adapter | |||
i2c-0 unknown SMBus I801 adapter at 4000 N/ | |||
</syntaxhighlight> | |||
In the example case the temperature sensor is connected to the i2c-ch341-usb device, and it is assumed the user has sufficient permissions to access the device. | |||
According to the datasheet, the temperature device uses address 0x40, so create a i2c device using the linux device and address: | |||
<syntaxhighlight lang="octave" style="font-size:13px"> | |||
i2cdev = i2c("/dev/i2c-1", 0x40) | |||
</syntaxhighlight> | |||
To read the temperature, register 0xF3 must be addressed and read (2 bytes of data): | |||
<syntaxhighlight lang="octave" style="font-size:13px"> | |||
TEMP_MEASURE_NOHOLD = hex2dec("F3"); | |||
fwrite (i2cdev, uint8([TEMP_MEASURE_NOHOLD])); | |||
pause (0.02); | |||
data = fread (i2cdev, 3); | |||
</syntaxhighlight> | |||
The data must be converted to a deg K value by making 16 bit number of the value and masking out unused bits. | |||
<syntaxhighlight lang="octave" style="font-size:13px"> | |||
value = uint16(data(1))*256 + uint16(data(2)); | |||
value = bitand (value, hex2dec("FFFC")); | |||
temp_Code = double(value); | |||
</syntaxhighlight> | |||
Now convert the temperature to degrees C and display: | |||
<syntaxhighlight lang="octave" style="font-size:13px"> | |||
C = (175.72*temp_Code/65536)-46.85; | |||
printf ("temperature read %f C\n", C); | |||
</syntaxhighlight> | |||
== TCP == | == TCP == | ||
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* Every read or write command opens and closes a new gpib session, since the linux-gpib session pointer is only valid for single command. | * Every read or write command opens and closes a new gpib session, since the linux-gpib session pointer is only valid for single command. | ||
[[Category:Octave Forge | [[Category:Octave Forge]] | ||