Sunday, July 3, 2011

Troubleshooting Pickit 2 Clone

Pickit 2 is a multipurpose tool : PIC programmer, debugger, UART and Logic analyzer provided by Microchip and the schematics is provided in Pickit 2 datasheet.

Schematics:



Specifications:



  1. Easy to use Windows® programming interface for programming Microchip's Flash family of microcontrollers

  2. UART Tool software for direct serial communications with a microcontroller RX/TX pins through the PICkit 2.

  3. Logic Tool software for simple logic signal stimulus and monitoring, with a 3-channel logic analyzer.

  4. PICkit 2 Programmer-To-Go support for programming devices without a PC.

  5. Code Examples in assembly and C.


Test methods:


Hardware – based:



  1. Ensure that PIC18F4550 is programmed.

  2. The VPP generated voltage should be about 11V to 13V while VDD is 5V.

  3. The P MOS used need to be IRLML6402 to provide enough power to programming.


Software-based:


Pickit 2 Troubleshoot can be found in TOOLS -> TROUBLESHOOT.. After you have clicked on the button, a pop up menu as shown below will appear. Click on NEXT.


The first step of troubleshooting is to verify the VDD. For PIC18F, the VDD is 4.5V, while for PIC16F, it is about 3.6V. Click on TEST to measure the VDD. The VDD can be further verified by using a multimeter at pin 2 and pin 3 of the ICSP.


Once the TEST button is clicked,  there will be a message whether it passed the VDD test or failed. If the VDD test failed, then, it is necessary to check whether the installation of components is correct.



Assuming the VDD test has passed, we will go on to verify the VPP now. The VPP for PIC18F is about 12V. This can also be verified further using a multimeter. For PICKIT 2 clones, it is often caused by the MOSFET( BS250) which is most likely used as a substitute for IRLML6402. Here, you can also test for MLCR 'high' and 'low'.


Once the VPP test has passed, we will move on to troubleshoot the PGC and PGD using a frequency counter or frequency measurement equipment. The range of the frequency when it is toggled at 30kHZ is about 26 – 28kHz. You may also try to pull the PGC and PID pin to 'high' or 'low' and measure it with your multimeter.


After everything has been done, click on the FINISHED button. Now, you are ready to use your pickit 2.

Conclusion


Pickit 2 is a great multipurpose tool that enables you to program and debug a PIC microcontroller. In addition, it also has a UART tool, and logic analyzer.

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