A customer was kind enough to share an example project for the U401/U421 centered around the 1-wire temperature device. The project was written in Delphi and is available for download (source and executable) here: https://www.circuitgizmos.com/files/u401delphi.zip
You can get the DS1822 from CircuitGizmos along with the U401 USB Interface and the U421 USB interface
Program and example features:
Port A is INPUTPort
A.7 is set for DS1822.
Port B is OUTPUT
Programmable scan rate
Programmable temperature threshold controls PortB.1
Option to log data to a local file
Optional choice of units
On-Demand temperature read
The example code is very readable, even if you don’t know object pascal. You can see just in this small part of code that reading a 1 wire device only takes resetting the bus and a few read and write commands. Easy-peasy.
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<span style="color: #008000;"> // Reset device USBm_Reset1Wire( dev, pin ); // Write "SkipRom" and "Conversion" USBm_Write1Wire( dev, $CC); USBm_Write1Wire( dev, $44); sleep(100); pin := $7; USBm_Reset1Wire( dev, pin ); // Write "SkipRom" and "Read Scratch Pad" USBm_Write1Wire( dev, $CC); USBm_Write1Wire( dev, $BE); // Process Family Code "22" (DS18B22) // Read two bytes of temperature result := USBm_Read1Wire( dev, data[0]); temp := inttostr(data[1]); val(inttostr(data[1]),T2,result); comb := T2; </span> |
This example code is provided AS-IS without warranty for distribution as example coding for the U4x1 in Delphi. It is easy enough to implement similar projects using Visual Basic, C, REALbasic, or the free RobotBASIC.
Enjoy!
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