DM163035+TEFLCST3 Microchip Technology, DM163035+TEFLCST3 Datasheet - Page 102

• Manufacturer Part Number: DM163035+TEFLCST3
• Description: KIT, PICDEMLAB+FLOWCODE-HOME BUNDLE/
• Manufacturer: Microchip Technology

Specifications of DM163035+TEFLCST3

• Kit Contents: Component Kit, PICDEM Lab Development Board, PICkit 2 Programmer/ Debugger, CD Containing User Guide
• Svhc: No SVHC (15-Dec-2010)
• Development Tool Type: Hardware / Software - Dev
• Silicon Manufacturer: Microchip
• Core Architecture: PIC
• Core Sub-architecture: PIC10, PIC12, PIC16
• Silicon Core Number: PIC10F, PIC12F, PIC16F
• Silicon Family Name: PIC10F2xx, PIC12F6xx, PIC16F6xx
• Rohs Compliant: Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

PICDEM
DS41381A-page 96
TM
speaker. Any change to the PWM frequency will result in a change in the frequency of
the tone emitted by the speaker. The PWM waveform is generated by simply toggling
the RC0 voltage level high-to-low or low-to-high each time through the main Software
Control loop. The frequency of the PWM will be determined by a delay that will tie up
the main Software loop for a period of time based on the value of the ADC result from
a voltage divider implemented using the thermistor and a 1KΩ resistor. The ADC result
captured will be decremented each time through the loop. Once the value reaches
zero, the loop will break and the Software Control loop will continue to execute. There-
fore, a higher resulting ADC value will generate a longer delay, decreasing the fre-
quency of the toggling RC0 pin. A smaller ADC result will generate a shorter delay,
thereby increasing the frequency of the toggling RC0 pin.
The schematic for this lab is shown in Figure 4-11.
FIGURE 4-11:
Referring the schematic in Figure 4-11, the RC0 pin connects directly to the gate of the
IRFD010 N-Channel MOSFET Q1. Notice that the PIC16F690 output pins can directly
drive MOSFET gates without the need of any driver circuitry. Resistor R4 pulls the gate
input low ensuring the transistor will remain OFF until a high voltage level is present on
the RC0 output. When the PWM transitions high, Q1 is ON and current flows through
the 8Ω speaker. The 100Ω R3 resistor is used to limit the current through the speaker
to manufacturer specified power ratings.
4.2.4.2
Using the firmware developed in the previous lab, make the following changes:
1. Create a new project in Flowcode using steps 1 through 9 from GPIO_Lab1 sav-
Lab Flowcode Companion Guide
ing the project as ADC_Lab2.fcf in the
C:\PICDEM_Lab\flowcode\ADC_Labs\ADC_Lab2 directory.
J8
PROCEDURE
Thermistor
10
1
2
3
4
5
6
7
8
9
SCHEMATIC FOR ADC LAB 2
V
RB4/AN10
U2
DD
V
R1
1KΩ
SS
RC0
R2
10 KΩ
20
19
18
17
16
15
14
13
12
11
J9
V
R4
10 KΩ
SS
V
DD
V
R3
100Ω
SS
Q1
IRFD010 N-Channel
MOSFET
© 2009 Microchip Technology Inc.
SP-
SP+
J19
8Ω
LS1