He may not look like much right now, but STEVE is an evolving project I’ve been wanting to start for quite some time. He is a robot, into which I will combine software, hardware, and mechanical design.
Currently STEVE is an AVR microcontroller and LM298 dual motor driver, strapped to a circa 1985 remote control car. Over the last few days, I began laying the foundation with serial communication, motor control, and power. In the next few weeks, I should receive the first order of parts to give STEVE senses.
- Ultrasonic range sensor
- 9-Degrees-of-freedom Intertial Measurement Unit (with compass)
- DS18B20 Temperature Sensor
- USB WiFi Adapter
- LM298 Motor Driver (a better unit)
- Servo (to pivot ultrasonic range sensor)
- Current Sensing
This is a great wish list, but without the software to tie it all together, not very useful. Therefore, I’m assigning my Raspberry Pi 2 B+ as STEVE’s brain. My vision is for the Pi to do all the heavy processing such as navigating, making decisions, and hosting the user interface for mission planning. That way, the AVR is only a hardware controller that manages Input/Output, and communicates bi-directionally with the Pi.
Over the last week the project has evolved very rapidly, and a new body is in the works. My 3D printer has some serious overtime coming up, as I begin designing and printing STEVE’s mechanical components. The ability to print new wheels, mounts, gears and body components is critical to the success of this project, and will also mean I can be very flexible with how everything is implemented.
I have a lot of freedom to do really cool things with this, and I look forward to posting regular updates on STEVE’s progress here!
The other day, my Denon AVR-1801 home theater receiver stopped working. It would power on, reach the point where it normally enabled the speaker outputs, but then it would shut off. The status LED would rapidly blink on and off.
The user manual suggested that the device was overheating, or that the speaker terminals were being shorted. The device was not hot, as it was just turned on. I unplugged all input and output cables, but that didn’t fix it either. Time to dig deeper.
A quick Google search revealed the following gem. There are four “surge” resistors in line with the ±15 VDC regulators: R141, 142, 148, 149. These 1 Ohm resistors weaken over time with every power-on surge, and the resistors from the factory were not strong enough. Armed with this knowledge, I opened my receiver to test these resistors.
The majority of external hard drives are nothing more than a case, a USB-SATA adapter, and a standard 3.5″ or 2.5″ hard drive. Despite having this extra hardware, they sometimes actually cost less than their bare counterparts. Why might this be? External drives usually only carry a 1 year warranty, while the average desktop drive today might get 2 years of coverage.
Above is a 3TB Seagate Expansion external hard drive. It has a USB 3.0 interface, and accepts 12VDC for power. I bought this a few years ago for $10 less than a bare 3TB SATA desktop drive.
Western Digital released a line of external hard drives where, when you take it apart, you don’t find a normal drive inside. Instead, the control board is actually a USB interface, not SATA.
Out of curiosity, and because I might put this drive inside my server in the future, I decided to tear it apart to see what I was working with.
8 months between posts is possibly a record on this site. That isn’t to say nothing interesting happened during all that time. Here is a quick recap to keep this site going:
This summer I studied German for 5 weeks in Germany. The entire trip was documented in great detail over here: danjoannis.com/heidelberg
A few videos have come out on my YouTube channel, some technical ones and a more artistic one to play with my new DSLR.
It seems someone made (another) viral video of their 3d printer playing the Imperial March, so here’s my take on it.
I’ve been putting more time into my Ecksbot, and keeping it maintained and improving print quality. I’ve expanded my filament collection thanks to Matt Durr, and been doing some work with original creations.
Ikea Roller Blind Mounts
Last week I uploaded my first public design to Thingiverse – I hope to create and share more projects soon!
In 2012, one of my posts were featured on Hackaday, a globally read and frequently updated aggregator of projects that modify, create, and otherwise hack. The traffic this garnered was enough to throw a couple 500 Server errors, but it also resulted in getting the attention of someone at Farnell/Newark.
I was contacted through the comments by a member of the Farnell team, who spent quite some time on my site and was “loving the content”. After further communications, he asked if I would be interested in reviewing products for them. Of course I said yes!
The question was, what would I review? After looking through some of their enormous catalog, I realized I’d rather create something out of the components I reviewed, and discovered the LM3886, a relatively inexpensive 68-watt audio amplifier. This is where the adventure began!
Do you have an old laptop whose battery struggles to reach 30 minutes? I used to.
An aftermarket 6-cell pack would have cost me around $40, which isn’t expensive, but the laptop was old (circa 2006) and not worth putting money into. I happened to have a fair number of Lithium-Ion battery cells “lying around”, and decided to upgrade my pack, not just with new cells, but with more cells.
This project was completed about a year ago, and I’m surprised I never posted it before!
Recently I was asked to configure a WiFi access point for a small business, who needed to have both a private internal network, and a public guest network.
There are many privacy concerns when having guests share your network. Specifically, it is desirable to:
- Disallow access to any computers on the private network
- Prevent network abuse (such as P2P file sharing)
- Secure the access point itself from tampering or unauthorized access
Of course, all this needs to be done without impacting the desired service: Internet access.
Although I found many guides online for setting up a guest network when the access point was also the primary router, I didn’t find any that worked for the intended network. So, after some trial, error, and research, I managed to get it to work.
This has been a long time coming. To summarize, Bell Aliant’s FibreOP Internet service includes a wireless router that has proprietary, limited firmware. It tends to suffer from latency and WiFi issues. So, I sought to replace it with my own wireless router! I ended up first building an overpowered but very functional pfSense Linux Firewall/Router.
Despite my monstrous UPS, I was not happy with the 1 hour run-time. The whole reason for the pfSense router was that FibreOP “hides” its Internet on a VLAN, which means a standard, consumer router will not be able to access the Internet. And from some forum posts I had read, it seemed DD-WRT was also incapable of it.
Finally, today, I pushed through and realized it takes only 4 simple steps to connect a DD-WRT router directly to the FibreOP modem.
Atlantic Canada is very fortunate to have access to Bell Aliant FibreOP Internet. It is a legitimate Fibre-to-the-Home (FTTH) service, in the same price range as cable and DSL offerings. Speeds start at 50/30 (download/upload in Mbps) for $70/month without any promotions.
As great as the Internet itself is, the wireless router they include is the bottleneck. It is an Actiontec R1000H. Our biggest headaches with it were low WiFi throughput and frequent WiFi drop, but the interface was a little lacking in advanced features.
The logical solution is to use another router. Unfortunately, Bell has configured the service in a way that simply swapping in a new router will not work at all!
Through some research and my own trial and error, I was able to install pfSense to a spare computer, and take control of my Internet.
Disclaimer: Do not follow these steps if you have Bell’s IPTV service, as it will no longer work. There are other sites that describe how to keep those services working, but mine does not. As well, though there should be no impact, I advise against doing this if you have FiberOP Home Phone and rely on it for emergency communications.
This is not an easy task. It requires a very good understanding of computer networking, basic understanding of Linux networking terminology, and availability of network equipment (switches, wireless access points, cables, NICs). Chances are you found this page because you meet some of that description. Just know that if it isn’t working out, you can plug in the Actiontec and pretend it never happened.