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 Page 1
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.
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.
− Analog Features: − 2 Analog Rail-to-Rail Comparator modules with: − Programmable rail-to-rail reference voltage (% of VDD) or 1.
BLOCK DIAGRAM: Page 5
MEMORY MAP: Page 6
D2 BAT54C VBUS DD+ ID GND USB GND1 GND2 USB Page 7 R8 390R/1% R9 240R/1% 3.3V 3 RXD SCL MISO SCK OPEN 2 1 1 RXD 2 TXD R6 20k 33k USB_POWER D-/PGC D+/PG D MICRO _B C5 10nF GND3 GND4 R5 4.7k 10uF/6.3V 3.3V C6 OUT ADJ/GND IN 1 3 5 7 9 BH10S 2 4 6 8 10 TXD SDA MO SI #SS UEXT_MALE UEXT USB C7 10uF/6.3V USB_DETECT R7 USB_POWER GND VUSB VR1(3.3V) LM1117IMPX-ADJ 3.3V POWER SUPPLY TXD 2 RXD 3.3V R4 4.7k 100nF C1 3.
BOARD LAYOUT: POWER SUPPLY CIRCUIT: MOD-USB-RS232 can take power from two sources: 5 VDC via pin holes VUSB and GND. 5 VDC via USB connector. The programmed board power consumption is about 20 mA with all peripherals enabled RESET CIRCUIT: MOD-USB-RS232 reset circuit includes R1 (4.7k), R11(240Ω/1%), D1 (BZV55C8V2), PIC18F14K50 pin 4 (RA3/MCLR/VPP). CLOCK CIRCUIT: Quartz crystal 12 MHz is connected to PIC18F14K50 pin 2 (RA5/OSC1/CLKIN) and pin 3 (RA4/AN3/OSC2/CLKOUT).
JUMPER DESCRIPTION: USB_PWR_3.3 This jumper, when is closed, connects PIC18F14K50 pin 17 (VUSB) – signal USB_VBUS, to VCC (3.3V). Default state is opened. UEXT_PWR_3.3 This jumper, when is closed, connects UEXT pin 1 to VCC (3.3V). When MOD-USBRS232 is used in host mode – this jumper must be closed, because the other module will be power supplied via MOD-USB-RS232. Default state is opened. 3_RX/3_TX This jumper, when is in position 3_RX, connects UEXT pin 3 to PIC18F14K50 pin 12 (RB5/AN11/RX/DT).
EXTERNAL CONNECTORS DESCRIPTION: UEXT: Pin # Signal Name 1 VCC 2 GND 3 RXD 4 TXD 5 SCL 6 SDA 7 MISO 8 MOSI 9 SCK 10 #SS USB Pin # Signal Name 1 USB_POWER 2 D-/PGC 3 D+/PGD 4 Not Connected 5 GND Page 10
MECHANICAL DIMENSIONS: Page 11
AVAILABLE DEMO SOFTWARE: USB to UART converter with Windows drivers for Serial Port Page 12
ORDER CODE: MOD-USB-RS232 - assembled and tested board How to order? You can order to us directly or by any of our distributors. Check our web www.olimex.com/dev for more info. Revision history: Board's Revision: Rev. A, created May 2010 Manual's revision: Rev.
Disclaimer: © 2011 Olimex Ltd. All rights reserved. Olimex®, logo and combinations thereof, are registered trademarks of Olimex Ltd. Other terms and product names may be trademarks of others. The information in this document is provided in connection with Olimex products. No license, express or implied or otherwise, to any intellectual property right is granted by this document or in connection with the sale of Olimex products.
