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20 

 

2.

 

Instead of using the white wire you could put a pull-down resistor between the PGM/LVP 
pin of your target chip and ground. A value of 10 .. 100 k

 should work fine. 

 
 

3.

 

If your Wisp648 was bought ready-made you can contact me to have it replaced by a 
corrected version. 
 

4.

 

You could repair the PCB. This requires cutting two traces and soldering one wire. The 
pictures below show the steps. This is probably best done after the board is assembled. 

 
Cut the two PCB traces at the 
indicated places.  

 

 

 

Now only the diagonal trace 
connects to the PCB pad. 

 

Use a short piece of wire to 
connect the two pads that were 
previously connected.  

 

This is what the result should look 
like. 

 

 

Содержание Wisp648

Страница 1: ...ts target circuit There is no need to extract the chip from its circuit put it in a programmer and put it back in the circuit after programming Instead you make a connection a few wires between the pr...

Страница 2: ...PIC pin functions not the pin numbers because the numbers of the pins used vary from chip to chip The table below works for most DIL chips but the chip s datasheet is the final authority Especially th...

Страница 3: ...d PGD pins and the rest of the target circuit is connected via a two resistors of 1k or higher The programming mode used by Wisp648 is called HVP for High Voltage Programming because a high voltage on...

Страница 4: ...onnector which is commonly used for wall warts The centre pin is positive which seems to be the most common polarity Unfortunately about 10 other connectors and 1 other polarity are also commonly used...

Страница 5: ...uivalent chip is the standard way to interface between the TTL signals and the RS232 signals But some dirt cheap PIC circuits interface the PIC pins directly to the RS232 signals This violates all des...

Страница 6: ...6F648A chip Remove the 16F648A chip from the Wisp648 Use that second programmer to program the new firmware into the chip Put the 16F648A chip back into the Wisp648 If you don t have a second programm...

Страница 7: ...t is open drain only it can not pull itself high only low The LED can be activated permanently by closing solder jumper J2 This could be done when the PCB is mis used as 7805 power supply only The 16F...

Страница 8: ...6 provide a minimal level of protection against misuse by limiting the current that could result They also damp ringing effects that could be caused by long wires Three connectors and a row of PCB pad...

Страница 9: ...nse to have them all point in the same direction Trim the wires Place and solder the four 1N5819 diodes The white band on the diodes must be at the side of the white band in the PCB silkscreen white p...

Страница 10: ...ader The latest version of the PCB uses a three pin header Place and solder the screw connector Place and solder the centre pin power connector I find it convenient to bend two of the pins before sold...

Страница 11: ...nserted in the hole with the square copper pad and marked with a Or all electrolytic capacitors must have their white bands towards the DB15 connector The capacitor nearest to the four diodes has a ve...

Страница 12: ...over the wires and the solder cups The picture shows white tubes but the color can vary Apply heat to shrink the heat shrink The fumes from the heat shrink are not healthy so do this in the open air A...

Страница 13: ...ake sure that it is really 5 0 V certainly not 4 5Vor 5 5V In either case you must put a 100nF capacitor over the power pins of the target PIC A larger capacitor 22 uF or more electrolytic is OK must...

Страница 14: ...in connector and screw connector wall wart The Wisp648 has two power connectors you can use the one you prefer The black 2 5 mm centre pin connector is convenient and matches the connector often found...

Страница 15: ...ound 4 PGD 5 PGC 6 Not connected The Wisp648 has a PICkit2 compatible pin header connector You can use this connector connect to a target board that has a PICkit2 compatible pin header connector The t...

Страница 16: ...3 26 PGM 4 25 5 24 PGM 6 23 7 22 GND 8 21 9 20 VCC 10 19 GND 11 18 12 17 13 16 14 15 28 pin skinny DIP 1 18 2 17 3 16 MCLR 4 15 GND 5 14 VCC 6 13 PGD 7 12 PGC 8 11 PGM 9 10 PGM 18 pin DIP The picture...

Страница 17: ...No build in 7805 power supply No build in TIP122 circuit could be added externally as dongle No LED No ICD2 and PICkit2 compatible connectors MCLR Vpp was forced to 5V via diodes and 1k resistor The W...

Страница 18: ...protection is a feature that the author of a program can enable if he chooses to do so If he did you are out of luck and you probably have no business copying that chip There are companies that will r...

Страница 19: ...ftware is modified to accept the identification Wisp648 Programming 18F fuses does not work Some PIC fuses settings in particular the enabling of the PLL in 18F chips require a power up to take effect...

Страница 20: ...it replaced by a corrected version 4 You could repair the PCB This requires cutting two traces and soldering one wire The pictures below show the steps This is probably best done after the board is a...

Страница 21: ...cant current MCLR Master CLear and Reset The reset pin available on most PIC chips This pin also serves to enable the PIC programming mode when the pin is quickly raised from 0V to the Vpp level On mo...

Страница 22: ...hip Vss Name for the negative or ground 0V power supply connection of an IC The dd part might in analogy with Vcc be derived from common source WISP Wouter s In System PIC Programmer My first PIC prog...

Страница 23: ...tight fit Aat Koch 2007 12 15 FAQ added Wisp648 identifies itself as Wisp628 Fris Kieftenbelt DB15 connector on the PCB must be male Rikard Bosnjakovic 18F PLL fuse FAQ added some textual refinements...

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