New PICkit 2 Clone
Completed this a while ago, but was too lazy to write a post. Anyways, here it is, my new and (aesthetically) improved PICkit 2 clone. As I’ve mention in this post, I didn’t come up with the circuit but got it from MCU Hobby.
What I did was redo the layout. Everything is surface mounted, even the header that’s not supposed to be.
First, let’s look at how my old PICkit 2 clone looked like:
If you’re observant, you’ll notice that I used an ink tube from a cheap pen as an extension of the switch. The tube had little protrusions near one end (originally kept the pen’s spring in place) which prevented it from slipping out from the casing. The PCB was made via toner transfer method, and there’s even silkscreen, though not very visible in the pics. It was a mistake to use clear-lens LEDs, way too bright. Anyways, this had served me well but I gave it to my brother. So, I needed a new one.
The heart of this programmer is no other than the PIC18F2550. I’ve kept the silkscreen to a minimum, only labelling the header pins and the indicator LEDs. The colors of the LEDs are green (POWER), yellow (TARGET), and red (BUSY). I really should have taken a photo with the LEDs on. The green isn’t true green, more of kelly-green, and the yellow seems to lean more towards orange.
The USB connector is a Mini B instead of the standard Type B on my old clone. This is actually pretty handy when powering a target circuit with the programmer. If you own a portable hard drive, you probably have one of those Y-shaped USB cables. This means the programmer and/or target circuit can draw current from two USB ports simultaneously.
However, I made an error with the pad layout for the USB connector. One pair of the support leads don’t line up with the pads. How did this happen? Long story short, I found a cheaper USB connector but forgot to change the layout.
Hehe…… Noticing a pattern? I like symmetry, hence the layout of the components seen in the photos. The MOSFETs are FDN335N and FDN302P, with a current rating of 1.7A and 2.4A respectively. Got a bunch of these from eBay, great stuff.
Errrr…… just more pictures to share… nothing interesting to say here.
The Eagle layout for this board (plus BOM and original schematic from MCU Hobby) can be found here.