122-28176 Parallax Inc, 122-28176 Datasheet - Page 225

• Manufacturer Part Number: 122-28176
• Description: GUIDE STUDENT PROCESS CONTROL
• Manufacturer: Parallax Inc

Specifications of 122-28176

• Accessory Type: Manual
• Product: Microcontroller Accessories
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• For Use With/related Products: Propeller Education (PE) Kit
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Contains lead / RoHS non-compliant

SetADC:
ReadADC:
CalcTemp:
PlotTemp:
Figure 6-23 is our test of the incubator using open-loop control. Note that we allowed
temperature to stabilize somewhat prior to changing the drive. With your experience of
the system curve you can begin to approximate whether drive is too much or too little
after a short while.
NEXT
RETURN
PWM ADC_Vminus, V_Offset * 255/500,100 ' PWM ADC offset voltage
PWM ADC_Vref, V_Span * 255/500,100
RETURN
LOW ADC_CS
SHIFTIN ADC_Dout, ADC_Clk, MSBPOST,[ADC_ByteValue\9] ' Clock data from ADC
HIGH ADC_CS
RETURN
TempF = (V_Span * 100)/255 * ADC_ByteValue + (V_Offset * 100)
RETURN
DEBUG "[", DEC TempF,",/,100]",CR
DEBUG IBIN Fan,CR
DEBUG "!O txtPWM = ", DEC PWM_Drive,CR
RETURN
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Close the Debug Terminal.
Open StampPlot macro sic_pc_incubator_open_loop.spm.
Connect and plot.
Adjust the PWM drive slider to achieve a stable temperature in the desired band
of 101.5 °F +/− 1 °F (yellow band in plot).
Once stable for 2 minutes, lightly blow continuously on the incubator test tube.
The fan may also be used if moved the farthest possible distance away. The fan
will also draw down the power supply voltage, causing heat output of the resistor
to drop in addition to increased losses.
' PWM ADC Span voltage
' Read ADC 0831
' Enable chip
' Disable ADC
' Calculate temp in 100ths
' Plot temperature/100
' Plot state of Fan as Digital
' Update PWM text