PIC16F88 senior design

[skimask]

DEFINE OSC 8
TRISA.1 = 1
TRISA.2 = 0
LOOP:
IF PORTA.1 = 1 THEN HIGH PORTA.2
GOTO LOOP

END

Also if the PIC is outputing a high and I remove the high input I would expect the output to drop as well, but it doesn't. Do I need to include a second IF, THEN statement to achieve this result?

If you read the code inside your 'LOOP', there's nothing there to tell the pin to go low if the input goes low...therefore...

DEFINE OSC 8
TRISA.1 = 1
TRISA.2 = 0
LOOP:
PORTA.2 = PORTA.1
GOTO LOOP

Also, check your datasheet regarding PortA and analog settings, section 12.0 of the PIC16F88 datasheet. You might see something there that might throw a wrench into your master plan!

[AlaskanEE]

I switched up to using B.1 as an input and B.2 as an output along with the portb.1=portb.2 and it worked well. After about 13 seconds, however, it stops working. Is this due to the fact that I'm relying on the internal oscilator or is there additional code that I don't know about. Also I looked over 12.0 and I see that PORT A pins would need additional lines of code to work, but I'm not fully understanding what their saying. Do the pins for PORTA have to be used for A/D conversion?

[skimask]

I switched up to using B.1 as an input and B.2 as an output along with the portb.1=portb.2 and it worked well. After about 13 seconds, however, it stops working. Is this due to the fact that I'm relying on the internal oscilator or is there additional code that I don't know about.

Common stuff:
Pullup on MCLR to Vdd?
.1uf cap across Vdd and Vss?
Power supply solid and smooth?
WDT config set to Off?

Also I looked over 12.0 and I see that PORT A pins would need additional lines of code to work, but I'm not fully understanding what their saying. Do the pins for PORTA have to be used for A/D conversion?

Keep reading past the first couple of paragraphs, read all about the registers relating to the A/D converter and the ports...You'll figure it out.

[rhino]

AlaskanEE -
Hint....
Read Section 12.0 as Skimasks suggests, review table 12-1. Now go to pg. 52 and review table 5-2. Look at the column that tells you what the POR, BOR and value after all other resets is. What does it tell you about the default setting of the registers in table 12-1?
Here's another good tool. Use this LINK to search the forums. It seems to work better than the built in search tool.

[mackrackit]

Look at this for PORTA setup

http://www.picbasic.co.uk/forum/showthread.php?t=561

and

http://www.picbasic.co.uk/forum/showthread.php?t=562

These are in the FACT section.

[skimask]

These are in the FACT section.

True that they are FACTs, but don't you mean FAQ section?

[AlaskanEE]

So if I want to use an analog input for port A I need to include a line of code such as this:

ANSEL = %00001111

if I want PORTA.0-PORTA.3 to be analog inputs, but if I'm getting serial data in through these pins can I keep them as digital input/output ports and just use the first digital high that comes in from the serial information to activate some output on another pin? Also I found a project that used the code 'ADCON1.7 = 1' to align bit 7 to be right justified and then 'ADCON1.4 = 0' and 'ADCON1.5 = 0' to default to using Vref. When I'm not doing any analog to digital conversion I shouldn't need any of these commands should I?

[mackrackit]

True that they are FACTs, but don't you mean FAQ section?

Details,Details,Details. FACTs in the FAQ section.

So if I want to use an analog input for port A I need to include a line of code such as this:

ANSEL = %00001111

Check the data sheet for the PIC you are using. I have not used the 16F88 yet, some PICs are a little different.

if I want PORTA.0-PORTA.3 to be analog inputs, but if I'm getting serial data in through these pins can I keep them as digital input/output ports and just use the first digital high that comes in from the serial information to activate some output on another pin? Also I found a project that used the code 'ADCON1.7 = 1' to align bit 7 to be right justified and then 'ADCON1.4 = 0' and 'ADCON1.5 = 0' to default to using Vref. When I'm not doing any analog to digital conversion I shouldn't need any of these commands should I?

Something like that.
Each analog pin can be set to digital or analog.
If you use serial the pin will have to be set as digital - true.
If you are not using any analog, set all as digital.

first digital high that comes in from the serial information to activate some output on another pin?

NO, serial does not work that way. When a serial signal say XYZ comes in something could be made to happen. If serial ABC comes in something else could happen. If serial QST comes in it could be ignored.

A digital LOW state is 0 to around 2 volts. Digital HIGH is around 3.6 to 5 volts.

In between is FUZZY