Operations and setup
Specifications on PIC24FJ256GA110 100 pin-out
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Figure 12.1 � Pin-out specifications� on
100 pin package of the PIC24FJ256GA110 μProcessor.
PIC24 Datasheet � page 6. http://ww1.microchip.com/downloads/en/DeviceDoc/39905e.pdf |
Pins used:
�
A/D Input Pins: AN0-AN11 � 25, 24, 23, 22, 21,
20, 26, 27, 32, 33, 34, 35
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UART Pins: RP10 (U2RX), RP17 (U2TX) � 49,50
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A/D Reference Pins: VREF-, VREF+
� 28, 29
Serial Communications Setup
Communications between the Hong Kong PIC24 Board and a
computer running terminal requires the following settings and wiring.
Terminal 1.9b Settings:
1. Baud
rate: 28800
2. Data
bits: 8
3. Parity:
None
4. Stop
bits: 1
5. Handshaking:
None
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Figure 12.2 � Screenshot of Terminal
program settings. |
Cabling wiring:
Wiring between a computer and the PIC24 is typically done
with a DB9F to DB9M straight through cable. The minimum wiring required is the
following
|
DB9F Pin |
Pin Name |
DB9M Pin |
|
2 |
Receive (RX) |
2 |
|
3 |
Transmit (TX) |
3 |
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5 |
Ground |
5 |
|
7 |
Request to Send (RTS) |
7 |
|
8 |
Clear to Send (CTS) |
8 |
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Figure 12.3 � Example of DB9F to DB9M
serial cable. |
Compiler Setup
The compiler used within the MPLab X IDE was the C30 compiler from Microchip, which is
based on the standard Linux gcc compiler.
The directory structure used in
developing this project used the following format:
|
Directory |
Description |
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C:\cclass\ |
Base directory for C programming
project files. |
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C:\cclass\headers\ |
Base directory for SSEL developed
include files used by projects. |
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C:\cclass\imu-2011-xx-xx\ |
Project directories with Year/Month/Day
in the name to differentiate between various milestones while developing the
project. (Ie. Imu-2011-12-12) |
The directory structure used within
the project:
|
Project Sub-directories |
Description |
|
\ |
main.c and various files during debugging phase. |
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\headers\ |
Header include
files for the project. |
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\drivers\ |
Driver files for the project. |
The settings required for the program to compile when
setting up the project for the C30/gcc compiler:
|
Include
Directories for Project |
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C:\cclass\imu-2011-xx-xx\headers\ |
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C:\cclass\headers\drivers\ |
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C:\cclass\headers\modules\ |
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C:\cclass\headers\os\ |
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C:\cclass\headers\pic24\ |
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Compiler
Directive |
Description |
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-std=c99 |
Allows for newer gcc
C compiler functionality |
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Figure 12.4 � Screenshot showing some
of the compiler settings required by this project. |
Serial Command Formats to Send to the PIC24F
The following commands have been
designed for controlling the IMU μProcessor:
|
Command |
Description |
|
MM00NN |
Switch System into pre-launch mode
(default startup). |
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MM11NN |
Switch System into data acquisition
mode (automatic when launch detected). |
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MM22NN |
Switch System into command mode for
data retrieval operations |
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FF00GG |
Turn on output during data
acquisition of ASCII formatted output for debugging purposes. |
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FF11GG |
Turn on output during data
acquisition of Hexadecimal formatted output for debugging purposes. |
|
FF22GG |
Turn on output during data
acquisition of Binary formatted output for debugging purposes. |
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FFxxGG |
Turn off output during data
acquisition (default). |
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DDxxxxxxxxEE |
Request data using retrieval using
two 32-bit long integers. |