Welcome to our site! EDAboard.com is an international Electronics Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.
The question: Where's the ASSY_ID0, ASSY_ID1 connected to the GND? I thing is a risc to leave this pins flying.
Second thing. Isn't the saturation voltage of the ULN2003 too high i.e. for the voltage pump? Isn't the choke too small? 100uH compare to 680uH is pretty low.
The MOSFET symbol on the schematic is wrong
Did someboty check the FLASH SPI memory? What kind of chip is mounted in oryginal PICkit3? Does the SST25VF040B work?
I've prototyped the PicKit 3 clone before doing a full layout. I built a breakout board for the PIC24 QFP in KiCAD then added the surrounding circuitry on a breadboard. Right now I don't have the VPP generation or the level shifting buffers as I wanted to prove to myself that I could program a 3.3 volt device before I had board built.
Using the firmware image above (and a few others I found off the web), I can successfully load the bootloader, RS, and AP for PIC18s through MPLAB, but I get an error of "PK3Err0026: Download program exec failed." when trying to do the same for PIC24 or PIC32. In all cases the firmware RS and AP loads initially seem to work OK before giving the error when the PK3 tries to re-connect after reporting a successful update. I can read the VDD voltage correctly in MPLAB even after the error occurs. I'm not sure if my problems are due to a bootloader hex that is not valid, taking too many shortcuts on my prototype, or just that the PK3 firmware is flaky even in production devices.
I too would be interested in what SPI memory is mounted on the PicKit 3. Does anyone have one that they can look at? I currently have the SST25VF040B on order but have not used it yet. I'm using the 25X40BV from Winbond right now as I had it already - that may be part of my problem.
I hope to prototype the VPP generation shortly as well as hook up a logic analyzer to the SPI memories to see if the PK3 is trying to read/write those. If anyone has made more progress on a clone, I'd be interested if they had any similar problems.
So I did some work on my clone. I am able to successfully program and verify a 24F device from the standalone programmer, but MPLAB is still having issues.
The more critical concern is that the SST25VF040B part. I looked at the SPI bus with a logic analyzer and it looks like the PicKit3 uses the UTIL1 (U3 on the Microchip schematics) operationally. The UTIL2 (U4) seems to only be exercises if you try to set up the programmer-on-the-go function).
When the PicKit3 powers up it does some reads and writes. The problem is that it is using the byte write command (0x02) and sending multiple data bytes. From what I see, the SST25VF040B supports only writing one byte of data with the 0x02 command. Even if you use the AAI command, you need to toggle CE after each byte you write. The PicKit3 does not toggle the CE during the byte writes.
It is my believe that the PicKit3 does not use the SST25VF040B part as I can't see that the PicKit3 would ever be able to program it. (Transactions on the bus appear to try to write the part and then later read the same address only to find it still at 0xFF.) Does anyone know what part is used on the real PicKit3?
no, the pickit2 pickit3 is a product of microchip , and the code in micro-controller( firmware ) is available , only making the circuit with there own circuit or with easily available parts
I was able to find that the original parts are Microchip's 25LC256I SN (U3) and Atmel's 25DF041A SH (U4). I haven't fully checked out the programmer-on-the-go features yet, so I can't speak too much to U4, but as soon as I started using the 25LC256 for U3, the board was able to program and verify a PIC24 without any problems. (Do not use the SST25VF040B for U3 as it will not work.)
Hi, I'm projecting a development board for the 32MX,24F and 33F family's. I would like to put a programmer/debugger on-board, PICkit 3 seamed to fit pretty well.
But I have a question, does the firmware supplied in the microchip website (together with the standalone application) contains the bootloader and AP on it ? If it doesn't what firmware have you fisrt programmed on it to get it working?
Hi.
I realized the schematic found by Taner (Altium project).
I have used 25LC256 and 25DF041A parts instead SST25VF040B.
I found a bug in the schematic (and in the PCB): UTIL_SDI and UTIL_SDO signals (pin 46 and 45 of PIC24FJ256GB106) are inverted.
I tried to program a dsPIC30 and its works!
Regards.
This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
By continuing to use this site, you are consenting to our use of cookies.
