MAX1234EVKIT [MAXIM]

Evaluation System/Evaluation Kit for the MAX1233/MAX1234 ; 评估系统/评估板MAX1233 / MAX1234\n


型号：	MAX1234EVKIT
厂家：	MAXIM INTEGRATED PRODUCTS
描述：	Evaluation System/Evaluation Kit for the MAX1233/MAX1234 评估系统/评估板MAX1233 / MAX1234\n
文件：	总12页 (文件大小：263K)
中文：	中文翻译
下载：	下载PDF数据表文档文件

19-2680; Rev 0; 10/02

MAX1234 Evaluation System/Evaluation Kit

General Description

Features

o Proven PC Board Layout

o Complete Evaluation System

The MAX1234 evaluation system (EV system) consists

of a MAX1234 evaluation kit (EV kit) and a Maxim

68HC16MODULE-DIP microcontroller (µC) module. The

MAX1234 is a complete PDA controller with an integrat-

o Convenient Test Points Provided On Board

o Fully Assembled and Tested

o 4 ✕ 4 Keypad Included

ed touch screen and keypad interface. Windows

95/98/2000 software provides a handy user interface to

exercise the MAX1234’s features.

o Interfaces to Common 4-Wire Resistive Touch

Screens

Order the complete EV system (MAX1234EVC16) for

comprehensive evaluation of the MAX1234 using a per-

sonal computer. Order the EV kit (MAX1234EVKIT) if

the 68HC16MODULE-DIP module has already been

purchased with a previous Maxim EV system or for cus-

tom use in other µC-based systems.

Component Lists

Table 1. MAX1234 EV System

PART

QTY

DESCRIPTION

MAX1234 EV kit

68HC16 µC module

MAX1234EVKIT

68HC16MODULE-DIP

MAX1234 Stand-Alone EV Kit

The MAX1234 EV kit provides a proven PC board layout

to facilitate evaluation of the MAX1234. It must be inter-

faced to appropriate timing signals for proper opera-

tion. Connect 5V and ground return to terminal block

TB1 (see Figure 8). Refer to the MAX1234 data sheet

for timing requirements.

Table 2. MAX1234 EV Kit

DESIGNATION QTY

DESCRIPTION

C1, C2

C3,C4

10µF, 10V tantalum capacitors

0.1µF, 10V X7R ceramic capacitors

Open

FB1

Ferrite bead

MAX1234 EV System

H1, H2, H3, H4

7-pin headers

The MAX1234 EV system operates from a user-sup-

plied 7VDC to 20VDC power supply. Windows

95/98/2000 software running on an IBM PC interfaces to

the EV system board through the computer’s serial

communications port. See the Quick Start section for

setup and operating instructions.

0.100in header, 2 ✕ 10

0.5mm ZIP SMT flex cable connector

Digi-Key HKF20CT-ND

Hirose FH12A-20S-0.5SH

2 ✕ 20 right-angle socket

SamTec SSW-120-02-S-D-RA

JU1

3-pin jumper

Ordering Information

Socket pins for 4 ✕ 4 keypad

Digi-Key ED5009 pin receptacles

The MAX1234 software is designed for use with the

complete EV system MAX1234EVC16, which includes the

68HC16MODULE-DIP module together with MAX1234

EVKIT. If the MAX1234 EV software is not used, the

MAX1234EVKIT board can be purchased by itself, with-

out the µC module.

4 ✕ 4 keypad, Grayhill Series 96,

front mount

Digi-Key GH5003-ND

Digi-Key GH5004-ND

MAX1234EGT (28-pin QFN)

MAX1615EUK

Ordering Information

U3, U4, U5

TB1

MAX1840EUB or MAX1841EUB

0.200in screw terminal block

PC board

PART

TEMP RANGE

0°C to +70°C

INTERFACE TYPE

User supplied

None

MAX1234EVKIT

MAX1234EVC16

3.5in software disk

Windows software

MAX1234 data sheet

MAX1234 EV kit data sheet

68HC16MODULE-DIP data sheet

Windows is a registered trademark of Microsoft Corp.

________________________________________________________________ Maxim Integrated Products

For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at

1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.

MAX1234 Evaluation System/Evaluation Kit

9) Connect the 4-wire resistive touch screen to the X+,

Quick Start

Y+, X-, and Y- pins of the header. For convenience,

Before you begin, the following equipment is needed:

a 20-pin 0.5mm flex cable breakout is provided by

headers H5 and H6.

• MAX1234EVC16 (contains MAX1234 EV kit board

and 68HC16MODULE-DIP)

10) Click Demo Touchscreen. The software tracks the

• A small DC power supply, such as a 12VDC 0.25A

motion of a stylus on the touch screen (see Figure 1).

plug-in transformer, or a 9V battery

11) Click Demo Keypad. The software tracks key

• An IBM PC-compatible computer running Windows

presses (see Figure 5).

95/98/2000

Detailed Description

of Software

The EV software’s main window configures the interrupt

handler and displays the internal registers in binary.

• A spare serial communications port, preferably a 9-

pin plug

• A serial cable to connect the computer’s serial port

to the 68HC16MODULE-DIP

To aid development of custom interrupt-driven soft-

ware, the Interrupt Handler tab (see Figure 1) handles

interrupt request (IRQ) response. Both PENIRQ and

KEYIRQ can be polled, and a set of checkboxes select

the desired response.

• Standard 4-wire resistive touch screen.

Do not turn on the power until all connections are

made:

1) Ensure that the MAX1234 EV kit’s JU1 jumper has a

shunt installed in the MAX1234 position.

The low-level registers are grouped by function. The

ADC regs tab (see Figure 2) controls the analog-to-dig-

ital converter, including the touch-screen digitizer. The

DAC regs tab controls the digital-to-analog output. The

KEY regs tab is for the keypad, and the GPIO regs tab

is for the general-purpose input/output (GPIO) pins.

Each register can be read or written by clicking the cor-

responding Read or Write button. (Registers that can-

not be written do not have a write button.)

2) Carefully connect the boards by aligning the 40-pin

header of the MAX1234 EV kit with the 40-pin con-

nector of the 68HC16MODULE-DIP module. Gently

press them together. The two boards should be

flush against one another.

3) Connect a 7VDC to 20VDC power source to the µC

module at the terminal block located next to the

on/off switch, along the top edge of the µC module.

Observe the polarity marked on the board.

The ADC, DAC, KEY, and GPIO buttons open an appli-

cation-oriented view of their respective functions.

Interrupt response is also handled by the main screen.

4) Connect a cable from the computer’s serial port to

the µC module. If using a 9-pin serial port, use a

straight-through, 9-pin, female-to-male cable. If the

only available serial port uses a 25-pin connector, a

standard 25-pin to 9-pin adapter is required. The

EV kit software checks the modem status lines

(CTS, DSR, DCD) to confirm that the correct port

has been selected.

Analog-to-Digital Converter Window

The MAX1234: Analog to Digital Converter window con-

trols the touch-screen digitizer, the auxiliary voltage

inputs, the temperature measurement, and the refer-

ence voltage. By default, the software automatically

waits for BUSY and then reads updated data after writ-

ing to the ADC control register (see Figure 3).

5) Install the EV software on your computer by running

the INSTALL.EXE program on the floppy disk. The

program files are copied and icons are created for

them in the Windows Start menu.

For improved accuracy, measure the reference voltage

and enter its value into Actual REF Voltage. This only

affects the BAT1, BAT2, AUX1, AUX2, and temperature

voltage reporting. The MAX1234 code outputs are not

affected. When the REFV control bit is changed, the soft-

ware automatically resets the Actual REF Voltage to 1.0V

or 2.5V, unless Ask before changing REF is checked.

6) Turn on the power supply.

7) Start the MAX1234 program by opening its icon in

the Start menu.

8) At the prompt, connect the µC module and turn on

its power. Slide SW1 to the ON position. Select the

correct serial port, and click OK. The program auto-

matically downloads its software to the module.

The temperature measurement can be further calibrat-

ed by adjusting Room Temperature centigrade and

“TEMP1 Vroom” for TEMP1 measurements, or by

adjusting “Temp2-Temp1 K/delta V” for Temp2-Temp1

measurements. Refer to the MAX1234 data sheet for

more information on temperature measurement.

_______________________________________________________________________________________

MAX1234 Evaluation System/Evaluation Kit

Note: The evaluation software’s main window provides direct access to all registers, and controls the interrupt response.

Figure 1. EV Software’s Main Window

Click Read KPDATA1 to read data masked by the col-

umn mask. Click Read KPDATA2 to read keypad data

masked by the key mask and column mask. Active key

presses are highlighted on the keypad display.

Digital-to-Analog Converter Window

The MAX1234: Digital to Analog Converter window con-

trols the voltage at the DACOUT pin. Enter the DAC

code value between 0 and 255, and click Write DAC.

The DAC can be powered off by clicking DAC Off (see

Figure 4).

Mask individual keys using the appropriate

R1C1...R4C4 checkboxes and clicking Write key

mask. Or mask an entire column using the C1–C4

checkboxes and clicking Write column mask. Masked

keys are grayed on the keypad display.

For improved accuracy, set the DAC output code to

255 and measure the actual DACOUT voltage. Enter

the full-scale voltage into DAC Full-Scale Voltage to

adjust the reported ideal DAC output voltage.

GPIO Window

The GPIO screen reassigns the keypad pins to general-

purpose input and output. Keypad pins R1–R4 and

C1–C4 can be individually assigned to GPIO. The

Write GPIO button writes all of the GPIO registers from

the checkboxes. Each GPIO pin can be configured as

an input, a totem-pole output, or an open-collector out-

put (see Figure 6).

Keypad Window

The Keypad window controls the 4 ✕ 4 keypad scanner.

Use the drop-down combo boxes to set up the keypad

control register, then click Write KEY Control. Refer to

the MAX1234 data sheet for suggested usage details

(see Figure 5).

_______________________________________________________________________________________

MAX1234 Evaluation System/Evaluation Kit

Note: The evaluation software’s main window provides direct access to all registers, and controls the interrupt response.

Figure 2. EV Software’s Main Window

inputs test measures the ADC analog inputs BAT1,

BAT2, AUX1, and AUX2. The ADC touch-screen inputs

test checks the PENIRQ interrupt pin, the BUSY pin, the

X+/X- and Y+/Y- drivers, and the analog inputs.

Diagnostics Window

The Diagnostics screen performs a battery of tests on

the system. From the main window’s View menu, acti-

vate Diagnostics. To select individual tests, change the

mode from EV Kit Production Test to Diagnostics.

Scroll to the desired test, check the appropriate boxes,

and click its Test button (see Figure 7).

Detailed Description

of Hardware

The Download test downloads the operating code to the

µC module, if it is not already running. The Initialize test

verifies power-on defaults values of the MAX1234 regis-

ters. The Readback test verifies the DIN, DOUT, SCLK,

and CS pins of the serial interface by writing test patterns

to the registers, and then reading back those test pat-

terns. The Keypad test checks the KEYIRQ interrupt pin,

the R1–R4 and C1–C4 pins, and the keypad controller.

The DAC analog output test uses the AUX2 pin to mea-

sure the DAC analog output. (Note: AUX2 should be tied

to DAC when performing this test.) The ADC analog

The MAX1234 device under test (U1) requires no sup-

port components except the supply bypass capacitors

(C1, C2). The 4 ✕ 4 keypad (K1) interfaces directly to

U1. Other styles of keypad can be evaluated by

unplugging K1 and installing a user-supplied keypad.

Commonly available touch screens using 20-pin 0.5mm

flex ribbon cable can be plugged into H6 and then

wired from H5 to the X+, X-, Y+, and Y- pins on the

breakout header. See Figure 8, the MAX1234 EV Kit

Schematic, and refer to the MAX1234 data sheet.

_______________________________________________________________________________________

MAX1234 Evaluation System/Evaluation Kit

Note: The ADC window controls the touch-screen digitizer, the auxiliary voltage inputs, the temperature measurement, and the

reference voltage.

Figure 3. Analog-to-Digital Converter Window

The EV kit includes a MAX1615 3V/5V linear regulator

and a set of MAX1840/MAX1841 level shifters to sup-

port using the 3V MAX1233 with the 5V µC.

Touch-Screen Equivalent Circuit

For prototyping purposes, a 4-wire resistive touch

screen can be simulated using two variable resistors

connected by a resistor and a switch. Variable resistor

X, connected between X+ and X-, should be approxi-

mately 100 to 500 . Variable resistor Y, connected

between Y+ and Y-, should be approximately 100 to

500 . Connect the center wipers of the two variable

resistors using a fixed resistor of approximately 300 ,

simulating the touch resistance. See Figure 9.

Evaluating the MAX1233

The MAX1233 is the 3V version of the MAX1234. Request

a free sample of MAX1233EGT. Using the MAX1233,

replace U1, and move the JU1 shunt to the MAX1233

position. In the software’s DAC window, change DAC

Full-Scale Voltage to 2.97V (90% of 3.3V).

Note: The DAC window controls the voltage at the DACOUT pin.

Figure 4. Digital-to-Analog Converter Window

_______________________________________________________________________________________

MAX1234 Evaluation System/Evaluation Kit

Note: The Keypad window controls the 4 ✕ 4 keypad scanner.

Figure 5. Keypad Window

Problem: Measurements are erratic, unstable; poor

accuracy.

Troubleshooting

Problem: No output measurement. System seems to

report zero voltage, or fails to make a measurement.

Check the reference voltage using a digital voltmeter.

Use an oscilloscope to check for noise. When probing

for noise, keep the oscilloscope ground return lead as

short as possible, preferably less than 1/2in (10mm).

Try increasing the acquisition time or settling time. Try

forcing measurements using ADC or KEY mode 00. Try

connecting a good quality 0.1µF ceramic capacitor

between the affected input and ground.

Check VDD and VLOGIC supply voltages. Configure

the ADC power-up settings to “always on” by writing

binary code 00-0000-01-xx-xx-xxx-x to the ADC

Control Register (see Figure 2). Then check the refer-

ence voltage using a digital voltmeter. Use an oscillo-

scope to verify that the BUSY pin is strobed low,

indicating that a measurement is performed.

_______________________________________________________________________________________

MAX1234 Evaluation System/Evaluation Kit

Note: The GPIO window reassigns the keypad pins to general-

purpose input and output.

Figure 6. GPIO Window

_______________________________________________________________________________________

MAX1234 Evaluation System/Evaluation Kit

Note: The Diagnostics window performs a battery of tests on the system. To select individual tests, switch the mode from EV Kit

Production Test to Diagnostics.

Figure 7. Diagnostics Window

_______________________________________________________________________________________

MAX1234 Evaluation System/Evaluation Kit

CS SCLK DIN BUSY DOUT

PENIRQ KEYIRQ

0.1

10V

DVDD

CS SCLK DIN BUSY DOUT PENIRQ KEYIRQ

DVDD

AVDD

X+

AVDD

0.1

10V

X+

Y+

X-

Y-

Y+

MAX1234

X-

Y-

GND

BAT1 BAT2 AUX1 AUX2 REF DACOUT R4

TERMINAL BLOCK

OPEN

TB1-1

TB1-2

AVDD

CONNECTOR

N.C.

X1 X2 X3 X4

SHDN

+12V

J1-5

J1-9

J1-10

J1-11

J1-12

J1-13

J1-14

J1-15

J1-16

J1-17

J1-18

J1-19

J1-20

J1-21

J1-22

J1-23

J1-24

J1-25

J1-26

J1-28

J1-30

J1-32

J1-33

LOGO

N.C.

J1-6

J1-1

J1-2

J1-3

J1-4

DVDD

MAX1615

GND

H5-1

H5-2

H6-1

H6-2

JU1

AVDD

DVDD

5/3

(FB)

H5-3

H6-3

FB1

OUT

H5-4

H6-4

H5-5

H6-5

10V

H5-6

H6-6

J1-36

J1-7

DATA

I/O

H5-7

H6-7

DIN

+5V

H5-8

H6-8

DVDD

SCLK

J1-8

CIN

CLK

RST

H5-9

H6-9

MAX1840

RIN

H5-10

H5-11

H5-12

H5-13

H5-14

H5-15

H5-16

H5-17

H5-18

H5-19

H5-20

H6-10

H6-11

H6-12

H6-13

H6-14

H6-15

H6-16

H6-17

H6-18

H6-19

H6-20

J1-37

J1-38

J1-31

J1-35

J1-27

J1-29

SHDN

+5V

GND

SHDN

RIN

DVDD

KEYIRQ

DOUT

RST

CLK

CIN

MAX1840

DVDD

+5V

DATA

I/O

N.C.

J1-34

J1-39

J1-40

GND

SHDN

RIN

DVDD

BUSY

RST

CLK

CIN

PENIRQ

DVDD

MAX1840

+5V

DATA

I/O

Figure 8. MAX1234 EV Kit Schematic

_______________________________________________________________________________________

MAX1234 Evaluation System/Evaluation Kit

X+

Y+

300

100 TO 500

X-

Y-

Figure 9. Touch-Screen Equivalent Circuit

Figure 10. MAX1234 EV Kit Component Placement Guide—Component Side

10 ______________________________________________________________________________________

MAX1234 Evaluation System/Evaluation Kit

Figure 11. MAX1234 EV Kit PC Board Layout—Component Side

______________________________________________________________________________________ 11

MAX1234 Evaluation System/Evaluation Kit

Figure 12. MAX1234 EV Kit PC Board Layout—Solder Side

Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are

implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.

12 ____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600

Printed USA

is a registered trademark of Maxim Integrated Products.

MAX1234EVKIT [MAXIM]

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