Datasheet

dsPICDEM™ 80-Pin Starter Development Board User’s Guide

3.5 BOARD SELF-TEST

The board self-test is provided for completeness only. Users do not need to run this

test.

1. Power the board using a 9V DC supply and the barrel power connector.

The LED marked D1 turns ON.

If D1 does not light:

- the LED is dead, or

- the regulator is dead, or

- the DC supply is not connected to the AC wall plug

2. Using a DMM set for DCV, check that 3.3V or 5.0V is available at location marked

DD and GND on the 80-pin header.

3. Connect a shorting plug on the RS-232 connector J1. This shorting plug should

have pins 2 and 3 connected to one another.

4. Short pins 2 and 3 on line connector J9 using a 0.1″ jumper.

5. Make sure J4 has a 0.1″ jumper on it.

6. To enter the Self-Test mode, hold down S1, press and release MCLR

, then

release S1.

The following four tests should run:

Test Description

UART Test This automatic test transmits 5 characters and receives them through

the serial port. During the test, LED RD4 blinks at a very fast rate

(8 blinks/sec). However, this test completes so quickly that, in most

instances, no noticeable blink of RD4 will occur.

Keypad Test During this test, LED RD5 blinks very fast. You must respond by pressing

S1 and S2. When you press S1, RD4 lights. When you press S2, RD7

lights. If both key presses are acknowledged by the dsPIC

DSC, then

the test passed. If you get no response or an incorrect response within 4

seconds, then the test is considered failed. In either case the test

automatically proceeds to the Potentiometer test.

Potentiometer Test During this test, LED RD6 blinks rapidly. You must first respond by turn-

ing Potentiometer R13 fully clockwise (RD4 will light) and then fully coun-

terclockwise (RD7 will light). Then you must move the potentiometer

wiper to a center position causing RD5 to light up. When this happens,

the test is complete. This test must be completed in 8 seconds or else the

test is considered failed.

Tone Test This procedure automatically tests the digital potentiometer and analog

operational amplifier. A sine wave, generated using the digital potentiom-

eter, is sent through the Op Amp circuit to the ADC of the dsPIC DSC

device. The sine wave is analyzed to determine if a smooth sine wave

has been generated. If all works well, the test passes. If there is a fault in

the op amp or digital potentiometer, then this test fails.