Pickit 3 and MPLAB IDE

Thread Starter

RodneyB

Joined Apr 28, 2012
697
I believe With a PICKIT 3 you can supply voltage to the target via PICKIT 3. But you must manualy turn this on in MPLAB.

HOW is this done 12 hours now and I cant get the demo project to work on the pickit 3 de bug express I just keep getting the following

PICkit 3 detected
Connecting to PICkit 3...
Firmware Suite Version...... 01.28.56
Firmware type......................PIC18F
PICkit 3 Connected.
PK3Err0045: You must connect to a target device to use PICkit
3.
 

Thread Starter

RodneyB

Joined Apr 28, 2012
697
Ok thanks very much I still don't know how to get it to switch on in MPLAD IDE 8.9

This is all so confusing. I dread to think how hard its going to write routines in C
 

Thread Starter

RodneyB

Joined Apr 28, 2012
697
Thank you so much, what a sense of satisfaction to basically flip a switch and get the demo board routine working.

Now to learn how to actually work in c
 
The PICKit3 will only supply 30mA to your target board so disconnect all peripherals, in and out or you will be sure to exceed current limits!

This may be all the problem is.
 

takao21203

Joined Apr 28, 2012
3,702
The PICKit3 will only supply 30mA to your target board so disconnect all peripherals, in and out or you will be sure to exceed current limits!

This may be all the problem is.
How do you know it will supply only 30mA?

It will supply much more.

I can run a 18F board at full speed and power a TFT as well.

It depends on the output voltage how much it can supply.
You can examine the schematic for that.

It has overcurrent sense as well, but that is not tripping at 30mA sharply.
 

ErnieM

Joined Apr 24, 2011
8,377
How do you know it will supply only 30mA?
Probably because he's RTFM:

PICkit 3 In-Circuit Debugger-Programmer Users Guide said:
2.5.3 Target Powered
...The recommended source of power is external and derived from the target application...

2.5.4 Debugger Powered
The internal debugger power is limited to 30 mA. This can be helpful with very small applications that have the device VDD separated from the rest of the application circuit for independent programming. However, is not recommended for general usage because imposes more current demands from the USB power system derived from the PC.
Skating along from "recommended conditions" towards "well it worked last time" is why the Space Shuttle blew up.
 

takao21203

Joined Apr 28, 2012
3,702
Probably because he's RTFM:

Skating along from "recommended conditions" towards "well it worked last time" is why the Space Shuttle blew up.
And these lines are useful how much so far?

It is a supporting pair of wheels for people who can not read schematics.

The most esoteric explanation I have read at another place: Silicon chip traces would degenerate from electromigration if currents are slightly exceeded.

While at the same time it is not clear if the current in the datasheet is a self contained limit, or the max. rating.

Things like space shuttles blow up because people believe things just because they are printed or they believe following all rules set out in print as such would lead to safety.

Really mixing a 2 Amps MOSFET with another which blows up at 35mA (if such MOSFETs do exist as logic level p-ch) makes how much sense whatshowever?
 

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tshuck

Joined Oct 18, 2012
3,534
Things like space shuttles blow up because people believe things just because they are printed or they believe following all rules set out in print as such would lead to safety.
The space shuttle Challenger blew up because management didn't listen to the engineers and cited previous success as being grounds to fly the shuttle anyway. They exceeded recommendations.

Just because the shuttle didn't blow up before doesn't mean they were safe. Likewise, exceeding values is not a safe bet, it may work for a while, but just add likely, you burn something out...
 

t06afre

Joined May 11, 2009
5,934
Oh well, at least I do not think any of the 12 lessons included in the PICKIT debug express package will blow up the PICKIT 3 programmer. However I do think the PICKIT 3 programmer is made to settle with 100mA. As it is the current limit for a USB 2 device. If it do not ask for more current. Microchip recommends using external power supply, and as a tip an old 5 volt cell phone charger may in most cases do the job just fine
 

ErnieM

Joined Apr 24, 2011
8,377
Oh well, at least I do not think any of the 12 lessons included in the PICKIT debug express package will blow up the PICKIT 3 programmer. However I do think the PICKIT 3 programmer is made to settle with 100mA. As it is the current limit for a USB 2 device. If it do not ask for more current. Microchip recommends using external power supply, and as a tip an old 5 volt cell phone charger may in most cases do the job just fine
By that logic you cannot make low power LED lighting since the line you plug it into can supply some 10 or 20 amps, making the LEDs take some 1,200 watts minimum.
 

takao21203

Joined Apr 28, 2012
3,702
The space shuttle Challenger blew up because management didn't listen to the engineers and cited previous success as being grounds to fly the shuttle anyway. They exceeded recommendations.

Just because the shuttle didn't blow up before doesn't mean they were safe. Likewise, exceeding values is not a safe bet, it may work for a while, but just add likely, you burn something out...
Yes problems with these O rings the engineers were aware of problems at low temperature.

Normally the PICKIT3 is used for flashing, and to run for a very short time. Sometimes for debugging. Easy to add a USB socket, regular or mini, and supply power from that.

This is what you normally should do for larger boards. They will often have USB anyway these days.

So far I never had problems even to run LED displays and small LED matrix. Sometimes for hours.

I don't have problems with MPLABX, only the menu is dropping off sometimes. One solution is to use the keys to navigate.

When I leave MPLABX running after a few days, I sometimes get all the memory clobbered up, and really 5 minutes disk activity with unresponsive system. It is a fast SATA drive, so I am wondering about this a bit. Java!
 
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