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Part II: Advanced Hacks, Tools, and Techniques

6. Test out the hardware

Plug the probe assembly into the ADC circuit board, plug a live Ethernet

cable into the SitePlayer board, and connect the SitePlayer power supply.

You should see a power LED light up on the SitePlayer board. If you have a

multi-meter handy, check the voltage across the power and ground pins of

the ADC chip. It should read +5V; if it does not, check your wiring. Follow

each wire from the SitePlayer board over to the ADC board to ensure that

each one is connected according to the schematic diagram. Disconnect

the ADC board and use a multi-meter to measure the voltage between the

ground and +5V pins.

If you are connecting the SitePlayer’s Ethernet port to a hub, use a straight-

through cable. If you are connecting the SitePlayer directly to your PC, use a

crossover cable.

Software Setup Instructions

The SitePlayer is a single-board computer that includes a complete TCP/IP

network protocol stack and a 10BaseT Ethernet port. It needs only a small

amount of code to fetch the data from the ADC and display it on a web

page.

The basic software that runs on the SitePlayer mini web server is a set of

special configuration files and a set of HTML web pages that are served up

when an external browser makes a request. The web pages provide a simple

user interface and contain embedded commands that read the temperature

and water levels from the ADC circuit board you just constructed.

First, you’ll download and test the pages and configuration files to the

SitePlayer using the tools provided with the SitePlayer board. Next, test out

the complete system.

The user interface HTML provided in Exhibit C that runs on the SitePlayer

is functional but simple. Feel free to hack up the code yourself to add

desired features.

1. Program the mini web server

The web pages and configuration files for the SitePlayer are loaded using an

RS-232 serial port. Make sure you have a spare cable if you did not purchase

the evaluation board. Connect the serial cable from one PC Com port to the

SitePlayer serial port.

For the PC you’ve connected to the SitePlayer, load all of the SitePlayer tools

according to the instructions included with it (or download them from the

SitePlayer web site).

Software Setup Instructions

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297

Chapter 15, How to Build an Internet Coffeemaker

Determine if your network runs a DHCP server. The SitePlayer is config-

ured to work by default in this environment. If your network uses static IP

addresses, you will need to set the SitePlayer for this mode. Connect a serial

cable between the SitePlayer and the PC, then start the SitePlayer Serial

Tester program. Set the new static address in the IP/Status window and

press Set IP Address.

Run the Serial Port Tester tool (included with the SitePlayer tools) and set

the IP address manually.

Place these files on your PC in a single directory:

• Listing 1: coffee.spd

• Listing 2: Index.htm

• Listing 3: SitePlayer index.spi

• Listing 4: refresh_index.htm

• Listing 5: refresh_index.spi

• Listing 6: water.htm

• Listing 7: water.spi

• Listing 8: pcadef.inc

• Listing 9: UDPsend_def.inc

These files can be found in Exhibit C of this chapter and on this book’s web

site at http://www.oreilly.com/hardwarehacking.

coffee.spd is the file used by the SitePlayer tools to build the data for the

web server. refresh_index.htm is the page that the server provides when you

first connect to it. refresh_index.spi forces a page refresh when the button

triggering the ADC read is selected. water.htm is a web page that shows

the water temperature. water.spi also forces a page refresh. pcadef.inc is

required by the SitePlayer to define the temperature/water sensor interface.

UDPsend_def.inc is used to define UDP functions on the board.

Launch the SiteLinker tool and the open the coffee.spd file. Next, under

Download, select “Make Download File.” If no errors are generated and

the SitePlayer board is connected to the PC and powered on, select the

“Download SitePlayer” option under the Download menu.

2. Test out the complete system

When the programming is complete,

test out the server to make sure that it

responds with a web page. To do this,

open a web browser on the machine

connected to it, and open the IP

address you specified for the SitePlayer

board. You should see a web page that

looks like Figure 15-16.

Figure 15-16:

Internet coffeemaker web page

Software Setup Instructions

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