Olimex MOD-USB-RS232 User guide

MOD-USB-RS232 development board

Users Manual

All boards produced by Olimex are ROHS compliant

Revision Initial, May 2011

Copyright(c) 2011, OLIMEX Ltd, All rights reserved

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INTRODUCTION:

MOD-USB-RS232 is module board with PIC18F14K50 microcontroller. It is
a simple USB to UART converter that features UEXT. It can be used to add Virtual
Com Port to other Olimex's module, or development board, with UEXT, but
without Com Port. The board can be configured in both device and host mode, de­pending on jumpers 3_RX/3_TX and 4_TX/4_RX (see Jumper Description below).
For using MOD-USB-RS232 with some of our modules, it's jumpers has to be
configured for host mode. For using MOD-USB-RS232 with some of our
development boards, it's jumpers has to be configured for device mode.

BOARD FEATURES:

• MCU: PIC18F14K50 20-Pin USB Flash Microcontrollers with nanoWatt

XLP Technology.

• mini USB connector

• status led

• male UEXT connector plus 10 pin cable for it

• RESET circuit

• FR-4, 1.5 mm, red soldermask, component print

• Dimensions: 35.70 x 25.83 mm (1.41 x 1.02")

ELECTROSTATIC WARNING:

The MOD-USB-RS232 board is shipped in protective anti-static packaging. The
board must not be subject to high electrostatic potentials. General practice for
working with static sensitive devices should be applied when working with this
board.

BOARD USE REQUIREMENTS:

Cables: The cable you will need depends on the programmer you use. If you use

PIC-ICD2-POCKET, or PIC-Kit3, you will need USB A-B cable. For PIC-ICD2­TINY, you will need RS232 cable. For PIC-ICD2, you will need USB A-B cable, or

RS232 cable. You will need adapter PIC-ICSP for programming, because the
board's ICSP connector is not Microchip's standard connector, it is a mini type one.

Hardware: Programmer PIC-ICD2-POCKET, PIC-ICD2, PIC-ICD2-

TINY, PIC-Kit3, or other compatible programming tool.

Software: MPLAB IDE

Note: This microcontroller does not support debug functionality.

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PROCESSOR FEATURES:

MOD-USB-RS232 board use USB Flash microcontroller PIC18F14K50 from

MICROCHIP Technology Inc. with these features:

− Flash Program Memory (words): 8k

− SRAM (bytes): 512

− Universal Serial Bus Features:

− USB V2.0 Compliant SIE

− Low Speed (1.5 Mb/s) and Full Speed (12 Mb/s)

− Supports Control, Interrupt, Isochronous and Bulk Transfers

− Supports up to 16 Endpoints (8 bidirectional)

− 256-Byte Dual Port RAM (DPRAM) for USB

− On-Chip USB Transceiver

− Flexible Oscillator Structure:

− Four Crystal modes, including High-Precision PLL for USB

− Two External Clock modes, up to 48 MHz

− EC Low, Medium, and High-Power modes

− Internal 31 kHz Oscillator

− HF-INTOSC 16 MHz

− Secondary Oscillator using Timer1 @ 32 kHz

− Fail-Safe Clock Monitor:

− Allows for safe shutdown if any clock stops

− Peripheral Features:

− Three Programmable External Interrupts

− Seven Interrupt-on-Change (IOC) Configurable for Rising, Falling or

Both Rising/Falling Edge Detection

− One Enhanced Capture/Compare/PWM (ECCP) module with Auto-

Shutdown and PWM Steering

− Master Synchronous Serial Port (MSSP) module supporting SPI mode,

and I2C. mode with Address Mask Capability

− Enhanced Universal Synchronous Asynchronous Receiver Transmitter

(EUSART) module:

− Supports RS-485, RS-232 and LIN compatibility

− Auto-wake-up on Start bit

− Auto-Baud Detect

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− Analog Features:

− 2 Analog Rail-to-Rail Comparator modules with:

− Programmable rail-to-rail reference voltage (% of VDD) or 1.024V

(nominal) band gap reference

− Comparator inputs and outputs externally accessible

− SR Latch mode

− 10-Bit, 9-Channel Analog-to-Digital (A/D) Converter module

− Special Microcontroller Features:

− Power-on Reset (POR)

− Power-up Timer (PWRT) and Oscillator Start-up Timer (OST

− Programmable Brown-out Reset (BOR)

− Software enable feature

− Configurable shutdown in Sleep

− Low/high-power configurable

− Four selectable trip points

− Self-Reprogrammable under Software Control

− Programmable Code Protection

− Single-Supply In-Circuit Serial Programming. (ICSP.) via Two Pins

− Operating Voltage Range of 1.8V to 5.5V

− Priority Levels for Interrupts

− Low-Power, High-Speed CMOS Flash Technology

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BLOCK DIAGRAM:

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