Why does the PIC16F723A fail to work when I program on it with my computer?

[Autamay]

I am working with a PIC16F723A chip and I am trying to program it to toggle a pin (RA1) on and off. I am pretty sure I have the circuit setup correctly (below is what I have setup), but for some reason I get an error when trying to program it....

So, I am using MPLAB X IDE v1.70 on OS X version 10.8.2. The project configuration in MPLAB X is setup with the device of PIC16F723A, hardware tools of ICD 3, and compiler toolchain as XC8 (Location: /Applications/microchip/xc8/v1.12/bin). There is no supported plugin board. It is NOT setup to power the target circuit from the ICD 3.

The error I am getting is "Connection Failed.If the problem persists, please disconnect and reconnect the ICD 3 to the USB cable. If this does not fix the problem verify that the proper MPLAB X USB drivers have been installed."

The warning I am getting is "CAUTION: Check that the device selected in MPLAB IDE (PIC16F723A) is the same one that is physically attached to the debug tool. Selecting a 5V device when a 3.3V device is connected can result in damage to the device when the debugger checks the device ID. Do you wish to continue?"

Here is how I have the circuit setup...
PIC16F723A PIN 1 is connected to ICD3 MCLR PIC16F723A PIN 28 is connected to ICD3 ICSPDAT PIC16F723A PIN 27 is connected to ICD3 ICSPCLK PIC16F723A PIN 1/ICD3 MCLR is connected to external VDD (+3.3V) through a 10K resistor (I have also tried a 4.7K) PIC16F723A PIN 8 is connected to PIC16F723A PIN 19 PIC16F723A PIN 19 is connected to GND PIC16F723A PIN 20 is connected to VDD (+3.3V)

I am checking the chip using a Tektronix Oscilloscope and when I continue from the warning message, I see data being transfered on the ICSPDAT pin, but nothing has changed for the RA1 pin.

Here is the code I am using:

Code: [Select]

#include <stdio.h>
#include <stdlib.h>
#include <pic16f723.h>

void main(void){
     int i = 0;
     TRISAbits.TRISA1 = 0; // RA1 to output
     ANSELAbits.ANSA1 = 0; // RA1 to Digital I/O

     while(1){
         PORTAbits.RA1 = 1;
         for(i = 0; i < 1000; i++);
         PORTAbits.RA1 = 0;
         for(i = 0; i < 1000; i++);
     }
}
I have checked the circuit design several times, I have checked to make sure the chip is correct (the silkscreen on it says PIC16F723A-I/SP 1142D3V). I have also tried programming it by supplying +3.3V from an external supply and a +5.0V from an external supply.

Here is the schematic:



Where I have attached an oscilloscope to SCOPE

I have tried the ICD3 test interface board and it came back saying everything is working correctly:

Code: [Select]

Test interface PGC clock line write succeeded.

Test interface PGD data line write succeeded.

Test interface PGC clock line read succeeded.

Test interface PGD data line read succeeded.

Test interface LVP control line test succeeded.

Test interface MCLR level test succeeded.

ICD3 is functioning properly. If you are still having problems with your target circuit  please check the Target Board Considerations section of the online help.
I have been able to successfully program a PIC16F1824 chip with this programmer and computer. I am using a PIC16F723A because I needed more I/O pins than the PIC16F1824 has. I have also used this computer to successfully program a Cerebot MX4cK. For some reason the PIC16F723A doesn't want to work. If I haven't mentioned it before, I have tried multiple chips.

[DaveLembke]

Have you been in contact with chip manufacturer to see if this is compatible with instruction sets your using.

I have seen before where you can initialize a chip that is similar but unable to control its I/O and its because while the handshake is there to initialize the chip that is similar but different, the instructions are different in controlling the I/O. I had issues like this a long time ago with the BASIC STAMP 2 chip, and the code I was trying to use to work with this chip was for BASIC STAMP ( original chip ) and someone else wrote the code for the STAMP chip and the STAMP 2 which I saw as being a better purchase wasnt 100% backwards compatible. The software to initialize seemed to work, but the instructions didnt work correctly because there was a difference in the chips internals between STAMP and STAMP 2. I contacted Parallax and they shared some info with me. It came down to that I had to rewrite a lot of instructions for the STAMP 2 chip that were different from the STAMP 1 chip which is just called BASIC STAMP.

Here is the BASIC STAMP chip info in case your curious and havent heard of it. It came out about 25 years ago and I messed with mine back in college around 1998 in a computer electronics course where I was messing with robotics. https://en.wikipedia.org/wiki/BASIC_Stamp

    (1992) BASIC Stamp 1 (BS1)
    (1995) BASIC Stamp 2 (BS2), with six sub-variants:
        BS2e
        BS2sx
        BS2p24
        BS2p40
        BS2pe
        BS2px
    (2002) Javelin Stamp
    (2006) Propeller\Spin Stamp

The BS2 sub-variants feature more memory, higher execution speed, additional specialized PBASIC commands, extra I/O pins, etc., in comparison to the original BS2 model. While the BS1 and BS2 use a PIC, the remaining BASIC Stamp 2 variants use a Parallax SX processor.