PIC-P28 development board
Users Manual
All boards produced by Olimex are ROHS compliant
Rev. D, February 2008
Copyright(c) 2008, OLIMEX Ltd, All rights reserved
Page 1
INTRODUCTION:
PIC-P28 board is development board which allow you to prototype and
develop code for all Microchip’s PIC microcontrollers with 28 pins.
What you can do with PIC-P28? A lot of stuff let’s see what we have:
PIC-P28 have RS232 connector and driver, so you can interface your
PIC microcontroller to other embedded or PC with RS232. The RS232
driver have 4 lines Tx, Rx, CTS and jumper selectable RTS or DTR.
The pin labeled RX is output and should be connected to PIC UART Tx.
The pin labeled TX is input and should be connected to PIC UART Rx.
Note that MAX232 driver on the socket is 5V device, so if you decide
to run your PIC on 3.3V you should replace it with MAX3232 which
works on 3.3V
The on-board ICSP connector allow you to program the PIC on the
board without pulling it of the socket, by ICSP programmer like PIC-
MCP, PIC-MCP-USB, PIC-PG1, PIC-PG2, PIC-PG3, PIC-PG4 or to
program and debug it with PIC-ICD2, PIC-ICD2-POCKET or PIC-ICD2-
TINY.
IMPORTANT: all programmers provide power supply through
ICSP connector during the programming PIC-P18 should not be
powered via the external power jack!
The power supply circuit have diode bridge after the power supply jack
which allow you to power this board with both AC and DC power
supply adapters. The input voltage could be anything within the range
+7.5 – 15V DC or 6-12V AC.
Voltage regulator is made with LM317 adjustable voltage regulator and
have jumper which selects what voltage you supply to the PIC
microcontroller +3.3V or +5V, so you can work with PICs on both low
and normal voltage.
The oscillator circuit is made with 20 Mhz crystal oscillator, so you
can run your PIC at maximum performance.
The RESET circuit is made with simple RC circuit and RESET push
button, the reason to not use RESET IC is that the board should
support both 3.3V and 5V operation while RESET ICs are on fixed
voltage.
PIC-P28 have user button for user input connected to PIC
microcontroller’s RA5 port. When RA5 port is initialized as INPUT you
will read “0” when the button is pressed and “1” when it is depressed.
Status LED is connected via jumper to PIC microcontroller’s RA0 port.
When your RA0 port is initialized as OUTPUT and set to “0” LED will
go ON, when RA0 port is set to “1” LED will go OFF.
PIC-P28 have handy GND pin for connection to oscilloscope.
Page 2
Page 3
FEATURES:
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•
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ICSP/ICD connector for programming and debugging
RS232 interface with MAX232 IC on socket
DIL28 microcontroller socket
Quartz crystal 20Mhz
LED to RA0 through jumper
user Button to RA5
Reset button and circuit
Power plug-in jack, accept AC and DC input
selectable +3.3V / +5V power supply voltage regulator (3.3V when jumper is
closed)
Extension slot on every uC pin
Gird 100 mils
GND bus
Vcc bus
Four mounting holes 3,3 mm (0,13")
FR-4, 1.5 mm (0,062"), green soldermask, white silkscreen component print
Dimensions 100x80 mm (3,9x3,15")
Page 4
PWR
IN
ADJ
OUT
G1
VR
LM317
+5V
SCHEMATIC:
B-DIL
R4
240/1%
6VAC
9VDC
390/1%
C8
100n
C7
100uF/16VDC
RST
C12
NA
LED_J
U1
1
MCLR#/THV
ICSP
R3
C6
470uF/16VDC
3.3V
R2
10K
C11
100n
20
D1
1N4004
1
2
3
4
5
6
VDD
330/1%
+5V
R1
R6
10k
LED
330
R5
+5V
Page 5
U2
C1+
1
C1
C4
4.7uF/25VDC
BUT
22p
C10
22p
C9
Q1
4-20MHz
2
3
4
5
6
7
4.7uF/25VDC
C1-
C2+
C2-
5
4
3
RA0/AN0
RA1/AN1
RA2/AN2
RA3/AN3
RA4/T0CKI
RA5/AN4
9
10
OSC1/CLKIN
OSC2/CLKOUT
PGD/RB7
PGC/RB6
RB5
RB4
PGM/RB3
RB2
RB1
INT/RB0
28
27
26
25
24
23
22
21
2
V+
C2
C3
4.7uF/25VDC
CTS
RX
TX
Rev. D
6
V-
4.7uF/25VDC
RS232
11
10
12
9
11
12
13
14
RC0/T1OSO
RC1/T1OSI
RC2/CCP1
RC3/SCL/SCK
RX/RC7
TX/RC6
SDO/RC5
SDI/SDA/RC4
VSS
18
17
16
15
8
19
6
7
8
9
1
2
3
4
5
14
7
13
8
T1IN
T1OUT
T2IN
T2OUT
R1OUT
R1IN
R2OUT
R2IN
PIC-P28
COPYRIGHT(C) 2008, Olimex Ltd.
http://www.olimex.com/dev
PIC28pin
J1
3
MAX232
16
U2P
GND
15
VCC
2
1
+5V
RTS/DTR
C5
12-RTS
23-DTR
4.7uF/25VDC
传感器
