- 您现在的位置：买卖IC网 > Sheet目录321 > DM163035 (Microchip Technology)KIT DEVELOPMENT PICDEM LAB
PICDEM TM Lab Development Board User’s Guide
The Initialize() configures the peripherals as follows:
? Ports
- Configure pin 13 as an analog input (using TRISB4).
- Clear the PORTC register.
- Configure RC0, RC1, RC2 and RC3 pins as digital output.
? ADC
- Select ADC conversion clock F RC.
- Configure voltage reference using V DD .
- Select channel 10 as the ADC input channel (Pin 13: RB4/AN10).
- Select result format left justified (10-bit result in ADRESH<7:0> and
ADRESL<7:6>).
- Turn on ADC module.
Note:
The ADC conversion clock is the time that will be used to convert the analog
voltage present on pin 13 to a 10-bit value in the ADRESH:ADRESL regis-
ters. It takes 11 of these conversion clock cycles to perform a complete
ADC. If the conversion clock period is insufficient, an incomplete ADC result
will occur. The electrical specifications for the PIC16F690 state that the
conversion clock must have a period of at least 1.5 μ Seconds or a fre-
quency of approximately 667 kHz. The ADC Module section of the data
sheet specifies acceptable conversion clock frequencies depending on the
main oscillator used to drive the microcontroller and should be referenced.
In this application, a dedicated internal oscillator for the ADC module is
used ensuring a conversion clock frequency of between 2-6 μ Seconds.
(see Table 17-16 in Section 17 of the PIC16F690 Data Sheet).
Next, the Get_Inputs() performs an ADC on the voltage present on pin 13. The
internal capacitor connected to the input of the ADC peripheral needs time to charge to
the voltage present on the pin. Therefore, software will need to implement a short delay
to allow for this charging time. The ADC Module section “A/D Acquisition Require-
ments” of the data sheet goes into great detail and includes an equation for selecting
an appropriate acquisition time. For the purposes of this lab, a simple 1mS delay
should be more than sufficient. These parameters become important in high-speed
applications where every μ S counts.
The GO/DONE bit in ADCON0 is used to start the ADC process when set to ‘ 1 ’. This
bit also serves as a flag that indicates when the ADC is completed (GO/DONE = 0 ).
Therefore, the Get_Inputs() initiates an ADC by setting GO/DONE then sits and
waits for the bit to clear indicating a completed conversion.
DS41369A-page 78
? 2009 Microchip Technology Inc.
发布紧急采购，3分钟左右您将得到回复。
相关PDF资料
DM164120-1
BOARD DEMO PICKIT 2 LP COUNT
DM164120-3
BOARD DEMO PICKIT2 28-PIN
DM164120-5
BOARD DEMO PICKIT 2 64/80-PIN
DM164123
KIT MANAGEMENT SYSTEM PICDEM
DM180021
KIT STARTER MPLAB FOR PIC18F MCU
DM183022
BOARD DEMO PIC18FXX22 64/80TQFP
DM183032
BOARD EXPLORER PICDEM PIC18
DM240001
BOARD DEMO PIC24/DSPIC33/PIC32
相关代理商/技术参数
DM163035+TEFLCST3
制造商:Microchip Technology Inc 功能描述:KIT PICDEMLAB+FLOWCODE-HOME BUNDLE/ 制造商:Microchip Technology Inc 功能描述:PICDEM, FLOW CODE, LAB, DEV KIT
DM163045
功能描述:开发板和工具包 - PIC / DSPIC PICDEM Lab Dev Kit (with PICkit 3) RoHS:否 制造商:Microchip Technology 产品:Starter Kits 工具用于评估:chipKIT 核心:Uno32 接口类型: 工作电源电压:
DM1-63-C
功能描述:端子 Metric Fem Disc non-insulated
RoHS:否 制造商:AVX 产品:Junction Box - Wire to Wire 系列:9826 线规:26-18 接线柱/接头大小: 绝缘: 颜色:Red 型式:Female 触点电镀:Tin over Nickel 触点材料:Beryllium Copper, Phosphor Bronze 端接类型:Crimp
DM1-63M-C
功能描述:端子 Metric Male Disc non-insulated, 0
RoHS:否 制造商:AVX 产品:Junction Box - Wire to Wire 系列:9826 线规:26-18 接线柱/接头大小: 绝缘: 颜色:Red 型式:Female 触点电镀:Tin over Nickel 触点材料:Beryllium Copper, Phosphor Bronze 端接类型:Crimp
DM164
制造商:SITI 制造商全称:SITI 功能描述:8x3-CHANNEL CONSTANT CURRENT LED DRIVER
DM1640
制造商:SANYO 制造商全称:Sanyo Semicon Device 功能描述:16 characters x 4 line Liquid Crystal Dot Matrix Display Module
DM1640-0AL1
制造商:未知厂家 制造商全称:未知厂家 功能描述:Optoelectronic
DM1640-0BL1
制造商:未知厂家 制造商全称:未知厂家 功能描述:Optoelectronic