Dwayne, I can't give you an exact answer as I use CCS ICD-U64, Load 'n Go or Mach-X programmers for all my PIC programming and debugging, however I can tell you that scenario you outline will work perfectly as I've done literally 100's of thousands of production PIC boards using the local on-board power to program the board (power supply and battery powered both). In fact, I setup all my PIC designs that way if at all possible for numerous reasons. Powering a PCB from the programmer is always problematic, so I make sure all of my designs have the MCLR/VPP line uncommitted (except for pull up resistor) and my local VDD is connected directly to the ICSP VDD pin as well as direct connections to the PGC/PGD lines of the CPU. I can't speak for the PICKit3 or ICD3 (although I do occasionally use an ICD3 so I'm pretty sure it works this way, the VDD supply output might be software enabled/disabled or have a hard jumper) but the CCS programmers have an internal jumper to supply VDD to the target, which I leave disconnected, requiring the target board to supply VDD during programming. The VDD pin on the target ICSP is connected to the programmer output buffers which drive the PGC/PGD lines so the logic level of the signals will match the target board. As a side benefit, this setup works extremely well for in circuit debugging= .. I've done target board voltages from 5V down to the low voltage programming limit of the particular PIC involved. That might be your only concern -- that the battery voltage on your target device meets the lower VDD programming voltage specification. I've seen this bite other people's designs I've reviewed before -- the PIC will run at 2.5V but it won't program there! Again, not sure of the PICkit3 or ICD3 but he CCS programmers actually reads the target VDD and displays it on their standalone programming application so it makes a good sanity check. Hope that helps a little. I'm almost positive you can do what you asked about. Matt Pobursky Maximum Performance Systems On Mon, 21 Dec 2015 10:40:58 -0700, Dwayne Reid wrote: > Good day to all. > > I'm working on a project that uses a 16F1782 that is always connected to > a battery. It is necessary that I be able to reprogram the chip after it > has been sealed into its enclosure. To that end, I am leaving a series > of small holes in the enclosure such that I can use pogo pins to touch > pads on the PCB within the case. The holes are sealed with a removable > covering (Kapton tape under adhesive velcro). > > I want to use standard chip programming hardware: PICkit3 or ICD3 in > standard High-Voltage programming mode. However, I don't know if it is > necessary for power to be removed from the PIC before the programming > sequence starts. > > Does anyone know if removing power is necessary before programming the > chip? If not, can anyone point me towards resources that will tell me? > > Many thanks! > > dwayne > > -- > Dwayne Reid > Trinity Electronics Systems Ltd Edmonton, AB, CANADA (780) 489-3199 > voice (780) 487-6397 fax www.trinity-electronics.com Custom > Electronics Design and Manufacturing --=20 http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .