OneWireViewer和iButton?快速使用

Introduction

Maxim's iButton products are designed so that a personal computer (PC) can easily read from or write to an iButton device. The OneWireViewer is a convenient demonstration software program that allows users to easily read from and write to iButtons with a Windows-based PC that has a USB port. (The Getting Started section discusses limitations when writing to EPROM-based iButtons.) The PC must also support Sun Microsystems' Java? program.

The OneWireViewer requires additional software drivers to allow the PC to communicate with the adapter. Both OneWireViewer and the required 1-Wire? drivers are bundled together and available for free download.

The OneWireViewer and 1-Wire drivers work with Windows XP? (SP2 or higher), Windows Vista?, and the Microsoft server operating system, Windows 2008. This application note gives detailed installation instructions for PCs using Windows Vista or Windows XP operating systems.

Getting Started

To communicate with your iButton, you need all of the items shown in Figure 1.


Figure 1. Required setup components.

Maxim? provides two iButton kits that include the adapter, reader, and iButtons for evaluation:

• DS1921K#—iButton Temperature Logger Starter Kit
• DS9092K#—iButton Starter Kit

All the components required for iButton evaluation are included in the kits. However, if the end application requires production quantities, then the adapters and reader/probes can be purchased separately by their individual part numbers. The DS9490R# adapter plugs into your PC's USB port. Most users find the adapter and the reader/probe in the starter kits useful for their evaluation and end use. Maxim sells other adapters separately for applications that require a serial-port interface instead of USB. To view other available adapters, go to our Adapters page.

Important Note: If you intend to program EPROM-based iButtons (DS1982, DS1985, or DS1986), you must use a serial-port adapter: the DS9097U-E25 with an external 12V power supply. This adapter has a 25-pin serial connector and requires a 9-pin to 25-pin serial converter to work with most PCs. The USB adapter can read these EPROM devices, but not program them.

The reader/probe has an RJ-11 modular connector that plugs into the adapter. Most users find the DS1402D-DR8# network cable useful for evaluation purposes. Maxim offers other alternate versions here.

All iButton devices communicate using the 1-Wire protocol. For designers doing printed circuit board design, 1-Wire devices in plastic packages may be more suitable than the iButton form factor. To evaluate 1-Wire plastic packaged devices, use the DS9090K 1-Wire Device Evaluation (EV) Kit.

Step 1. Java Installation

Many PCs have Java software installed at the factory. The OneWireViewer requires Java (version 5, update 8 or higher). To check if you have Java installed or what version you have, go to the Java website. Click on the appropriate links that autodetect and verify the version of Java installed on your PC. If your version is out of date, follow the links to download and install the latest version.

Step 2. Download Bundled OneWireViewer and 1-Wire Drivers

NOTE: DO NOT INSERT THE DS9490R# USB ADAPTER INTO THE PC YET. THIS SHOULD NOT BE DONE UNTIL STEP 4, AND WILL USUALLY CAUSE INSTALLATION PROBLEMS IF DONE BEFORE STEP 4.

Download the bundled OneWireViewer and 1-Wire drivers here. These pages have pulldown menus to help select the correct file for the operating system that you are running. Microsoft operating systems come in 32-bit and 64-bit versions. If you are not certain which version you have, the download page has a link to an applet that autodetects the correct version. Click on the hyperlink for the text, "Is my computer running a 32-bit or 64-bit operating system?" to run this autodetect applet.