A reader of this blog, Frans Stevens, pointed out that the schematic for my Build Your Own PICkit 2 schematic had an error. The USB connections to D+ and D- were backward. I quickly looked over the schematic and also the PCB layout because I've built many of these and they all worked. But I found out he was right, the schematic was wrong. Luckily the PCB was correct and that is why all my PK2 programmers work fine.
Pin 2 of the USB needs to connect to D- and pin 3 needs to connect to D+. I had them backwards in the schematic. So I immediately updated the schematic and uploaded to the Build Your Own PICkit 2 page. Its awesome to have such supportive readers with the willingness to share any errors they find. I want my information to be accurate but I'm human and do make mistakes. Thanks Frans.
I had a little bit of free time after the Thanksgiving Holiday so I created a few 3D printer projects. One was an Advent Calendar Christmas Tree. This took all the space my Davinic 3D printer could support and took two print runs to finish it.
The blocks slide out and can be flipped so the number is hidden. Everyday you take one number and flip it until only #1 is left and that is Christmas Eve. The design was done in Tinkercad and the full build is shown on my YouTube Channel and in the video below.
I did it as a count-down to 1 but you can reverse the blocks and make it show the calendar day so place the #1 in the bottom and the #24 at the top. The blocks slide out easily and can be pushed from the back. At some point I could print one of these and put LEDs on the blocks so a Microcontroller can do the count-down automatically.
All the files are open source on Tinkercad and the .stl's are available at Thingiverse.
I've returned as a columnist for Nuts & Volts Magazine. My column titled "Getting Started with 3D Printing" started today in the December issue of Nuts and Volts Magazine. I wrote the "Getting Started with PICs" column from 2006 thru 2009 and it ended for reasons beyond my control but I'm happy to be back.
The idea behind the column is to help anybody just getting started with 3D printing with tips and tricks that I've learned or will soon learn as I get deeper into 3D printing myself. There is so much to learn beyond downloading a thingiverse file and printing it. And with the various low cost printers available, I thought the timing was right to help others get started.
If you are a regular reader of this blog though, you know I've been writing about my 3D printer adventures for some time. But the N&V column is written for the electronics hobbyist who wants to design that custom case or special mount for their electronic project. There is so much 3D printing can offer and I feel like it's just getting started. Reminds me of the early days of the PC. I think we are still waiting for that killer app or killer print that will make everybody want a 3D printer the same way Visicalc did for the early PCs.
I've also added some new videos to my YouTube Channel that weren't posted here. I'm trying to separate this blog and the YouTube Channel a bit because I still want to help those who still are looking for my help with their electronics hobby. If you are a subscriber to N&V then check out the column. If not, maybe find it on the newsstand and see if it something you'd like to read. I hope to keep that column running for a long time.
I recently bought a CLOUDBIT kit from littleBits and it's expected to arrive in a few days. What interested me the most is the application they advertise for a doorbell switch that will send you a text message when the switch is pressed. The idea is to indicate someone is at your door even if you aren't home at the time.
I found this idea interesting because there are so many projects where I'd like to receive a text message indicating something timed out or a process completed. That way I don't have to sit and monitor it or check back often. One such process is 3D prints. When a print is done I'd like to receive a text message letting me know.
I've read about multiple different modules that allow you to connect to the internet but I found most of them very confusing. That was until I found littleBits. The module has a linux computer on-board so this is more than just a little plug and play module, it's a very complicated module that reduces the internet access down to a high/low signal.
The module relies on an internet service called IFTTT which stands for If That Then This. I've visited the site and it appears to be some kind of scripting language setup that allows you to easily create actions based on various inputs and outputs all connected through the internet. I hope to understand it a lot better when I get the CLOUDBIT running on my Davinci 3D printer so stay tuned if you have any interest in this type of project.
In the Make Magazine November 2012 issue, they ran a 3D print competition with many of the existing available 3D printers. They ran a test print that had some unique features. It had an unsupported arch, round and hex holes, posts and a box with walls of different thickness. Then each printer created it at default settings.
I decided to try the same print on my Davinci 3D printer and the results were great. I printed with and without supports so the arch failed in the non-support but everything else was fine. It's still not clear to me if support would have been permitted or not. I produced a YouTube video showing the steps and the results.
The .STL file is available on Thingiverse for anybody to try. I printed it at different levels or 0.2 layer and 0.4 layer. The default on my XYZware is 0.4 layer, 10% fill and standard shell and standard speed. The support was low fill. Both the 0.2 and 0.4 looked great.
It's true that the Davinci had two years of development over the printers in the magazine, since it wasn't released until two years later, but a sub $500 printer wasn't available back then either. So I'm once again sold on the quality of this Davinci printer.
I found a really interesting 3D print file of a single-print hinged box. Not two pieces snapped together, but rather a single print. The design was created by a user name anewsome on thingiverse. The design prints both halves of the hinge together so the 3D printer needs to be able to print very tight tolerances. The question was, would my Davinci 1.0 3D printer be up to the challenge.
I've fixed a few flaws on my printer such as a broken bearing and a wobbly base. With that my 3D prints were coming out excellent. So my guess was the Davinci could deliver and it did. The video above from my YouTube Channel shows the steps to create the hinged box.
This just shows that a low cost 3D printer can deliver as well as the higher priced units. It also shows you don't need to hack the hardware or software to get great results.
In my book Programming the BASIC Atom Microcontroller and also in my book Getting Started with PIC's - Volume 2, I wrote about creating large characters on a 4x20 LCD. It was also printed in the 2007 September issue of Nuts & Volts Magazine for my column Getting Started with PICs that ran from 2006 thru 2009. I used the trick of creating custom characters on the first 8 locations of the Character RAM in the LCD HD44780 driver chip to build the large digits. The topic of creating custom characters came up recently on the Great Cow Basic forum so I thought I would repost the article here on my website under the download page.
It was written to run on the Basic Atom microcontroller but the concepts and description in the article explain how to create the effect, so it should be easy to adapt it to any microcontroller. I know I've done it with PICBASIC but I could not find any sample code in the ever expanding list of code samples on my computer.
Hopefully this repost of the article will be helpful to somebody out there in my audience. I may repost all the Getting Started with PIC's articles over time as a bonus to my readers. They are a bit dated, but not out of date. So they may be helpful. If you are interested in that, please comment below.
My father was a mechanic and later an auto body repairman who performed miracles to bring back vehicles that were smashed in traffic accidents. So I guess the fact I grew up around cars and the fact I live in the MotorCity was a natural path to get an electrical engineering degree and work for Ford. I spent a good part of my younger years working on, and racing stock cars. But somewhere along the way my electronics hobby, and profession, took over and I spent more time build circuits and writing code than I did modifying engines and fixing sheet metal.
So the fact I've been spending more time with my 3D printers may not be what you come to this blog for but they will come together more as time goes on. But for now I'm just having fun learning everything I can about this interesting tool.
My YouTube Channel seems to get a lot of people who build 3D projects for kids. And since as a kid I loved playing with race cars, I decided to build one for the kids out there.
I used Tinkercad once again to create a Bugatti style racer but with a twist. I made it with plastic bolts that screw into the chassis. This allows the child to replace a tire the same way they change tires in a NASCAR race. And since the source files are all available on Tinkercad and also the .stl files on Thingiverse, anybody can easily recreate this. That is one of features of 3D printing that I really like. You can easily share the complete design and also easily edit it and share back. Software isn't even quite this easy.
I spent the weekend creating a YouTube video showing how I made the project so hopefully it helps others learn a few tricks. I know I learn a lot from looking at others designs. I've been studying some very creative plastic cases for Arduino/chipKIT/CHIPINO style boards that people have shared on Tinkercad. From there I can easily modify them to fit my needs.
So in the end, this column and my YouTube Channel will evolve to merge the 3D printing with electronics on future projects. That's when the fun will really begin.
I recently donated some of my shield files to the CHIPINO.com website. They are just files from my kickstarter projects that I was sharing anyway but this way the CHIPINO team or anybody looking for CHIPINO support shields can get them at one location. I helped create the CHIPINO with a group of friends because I wanted to see a Microchip PIC based option to easily use the various Arduino shields. From there CHIPINO has grown on its own.
The desire to make CHIPINO completely open source and not just the current non-commercial version is still something I'm pushing for. It worked out great for Arduino though maybe not the Arduino creators. The Arduino kind of took on a life of it's own and the originators kind of lost control. That is the scary part for some of the CHIPINO team.
Because CHIPINO was designed to work with a Programmer, and not a bootloader, it allows CHIPINO to use any 28 pin PIC16F or 18F device that operates at 5v. That offers a lot of options. This also made the CHIPINO automatically grow with all the advancements in the Microchip PIC world. Programming a CHIPINO from a PICkit 2 or PICkit 3 with MPLAB or MPLAB X or any third party IDE and any compiler that produces a .hex file for PICs is possible with the current setup and thus makes it universal for developers of all types. From hobbyist to professional.
It's one of the advantages I see to the CHIPINO has over Arduino which locks you into a crude IDE and only a couple chip options. But its clear that Arduino has taken over the electronics world so I'm clearly in the minority. But that is why I'd like to see the complete open source so others can take CHIPINO further. Time will tell. I'm also looking at changing my shield designs to completely open source as well (remove the non-commercial portion) as soon as the agreement I have with Howtronics.com expires.
I have other designs to clear out of my lab which I'll be releasing open source over time. Each will probably be a project on my YouTube Channel. I have just so many designs I've worked on over the years and its time I just let them go for others to fully enjoy and possibly take them further than I ever could.
My 2nd Davinci 3D printer had an issue that I didn't see on my first one. It was shifting the prints during the build. At first I thought maybe it was the software file, but the same file built fine on my original machine. Everything pointed to a defective machine and we considered taking it back. But a little bit of investigation into the issue led to a discovery that the print bed was loose.
As the video above shows, the glass on top of the heated bed was loose and could move around in its frame. This allows the print to shift as the extruder moved around. When the plastic is extruded, it sticks to the previous layer and as it moves, it would pull the print along and the loose base would move with it. This made for some really ugly prints. The bearing on the lower part of the base frame was also loose in its socket. All this caused a shifting print bed and the prints showed the crappy results.
I made a few crude fixes to test out the theory that the loose bed was the culprit. To start I jammed an Exacto blade between the loose bearing and its mount. The to secure the glass top over the heated bed, I squeezed folded sandpaper between the edge of the glass and its frame. As amazingly crude as the fix was, it worked excellent. In fact the sandpaper is still in place and running well. I used epoxy to hold a broken piece of the exacto blade in place as a more permanent bearing brace. Watch the video to see more detail on this issue. Maybe it will help others who are having this issue with their Davinci.