Controlling a Color TFT Display with PIC32

Sometimes it feels like everyone out there is using Arduino. It’s easy to find tutorials and libraries to get things working with Arduino, but if you want to use another platform you might have more trouble. [Tahmid] ran into this problem when he decided to try using a PIC32 to control a 2.2″ color TFT display from Adafruit.

Adafruit is really good about providing tutorials and Arduino libraries for their products. It makes it really easy to get up and running… if you are using Arduino. All of their libraries are open source, which means that the community can take them and modify them as needed. [Tahmid] decided to do exactly this and fork the Adafruit libraries over to the PIC32 platform in C. It’s a great learning experience. You get to see how (good or bad) other people code, and it immerses you in the differences between two different chip families.

He’s released the libraries online for others to use. He says that he’s heavily commented the code to try to make as self-explanatory as possible. The display interfaces with the PIC32 using SPI. The demo video below shows the screen up and running and demonstrates the crisp color graphics. Continue reading “Controlling a Color TFT Display with PIC32”

The Dan64: A Minimal Hardware AVR Microcomputer

[Juan] sent us his writeup of a microcomputer he built using an Arduino UNO (AVR ATmega328p) and some off-board SRAM. This one’s truly minimalistic.

Have a look at the schematics (PDF). There’s an Arduino, the SPI SRAM, some transistors for TV video output, and a PS/2 connector for the keyboard. That’s it, really. It’s easily built on a breadboard in a few minutes if you have the parts on hand. Flash the Dan64 operating system and virtual machine into the AVR and you’re good to go.

Now we’ve seen a few 6502-based retro computers around here lately that use a 6502 paired with a microcontroller for the interfacing, but they’ve all been bulky three-chip affairs. [Juan] wins the minimalism prize by using a 6502 virtual machine implemented in the AVR to reduce the parts count down to two chips for the whole shooting match.

Using a 6502 virtual machine was a crucial choice in the design, because there are 6502 cross compilers that will let you compile and debug code for the microcomputer on your macrocomputer and then load it into the micro to run. This makes developing for the micro less painful.

How does it load programs you ask? The old-fashioned way of course, using audio files. Although rather than using the Kansas City Standard as in days of yore, he encodes the data in short and long pulses of square waves. This might be less reliable, but it sure saves on external hardware.

Continue reading “The Dan64: A Minimal Hardware AVR Microcomputer”

How To Properly Crimp Electronics Connectors

Putting crimp connectors on wires is one of the most tedious things you’ll do. It’s not easy, either, unless you have some practice. Before you start digging in to a pile of connectors, crimp terminals, and wire, it’s a good idea to know what you’re getting into and Gogo:tronics has a great tutorial on how to crimp electronics connectors.

Crimping connectors onto wires requires the right tool, and the most important for this task is – surprise – the crimping pliers. These pliers press the crimping wings of the connector into each other, a task made much easier on the non-ratcheting pliers if you use a rubber band to hold the jaws of the crimping pliers open just enough to hold a crimp connector.

The general theory for crimping all types of connectors is to strip a little bit of insulation off the wire. Then, put the connector into a suitably sized space in the jaws, insert the wire, and crimp it down. For non-ratcheting pliers, it’s suggested the connector be re-crimped with the next smallest hole in the jaws.

There are a few connector-specific tips for the most common connector types, too. Dupont connectors – those flat, black connectors with a 0.1″ pitch – go together like you think they would, but for larger connectors – VH and XH-style – it’s important to use the right wire gauge and not to squish the square female part of the connector.

Retrotechtacular: The Bessemer Converter

Here’s a rose-colored look into the steelworks at Workington, Cumbria in northern England. At the time of filming in 1974, this plant had been manufacturing steel nonstop for 102 years using the Bessemer process. [Sir Henry Bessemer]’s method for turning pig iron into steel was a great boon to industry because it made production faster and more cost-effective.

hot ingotsMore importantly, [Bessemer]’s process resulted in steel that was ten times stronger than that made with the crucible-steel method. Basically, oxygen is blown through molten iron to burn out the impurities. The silicon and manganese burn first, adding more heat on top of what the oxygen brings. As the temperature rises to 1600°C, the converter gently rocks back and forth. From its mouth come showers of sparks and a flame that burns with an “eye-searing intensity”. Once the blow stage is complete, the steel is poured into ingot molds. The average ingot weighs four tons, although the largest mold holds six tons. The ingots are kept warm until they are made into rail.

The foreman explains that Workington Works would soon be switching over to a more modern process. As it was, Workington ran a pair of Bessemer converters on a 40-minute schedule, ensuring constant steel production from ore to rail. Between 1872 and 1974, these converters created an estimated 25 million metric tons of steel.

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Time for the Prize: Big Water

I inadvertently started a vigorous debate a few weeks ago with the Time for the Prize post about a shower feedback loop. That debate was on the effect of curbing household water since households make up a relatively small percentage of total use. I think we should be thinking of solutions for all parts of the problem and so this week we’ll be looking for ideas that can help conserve water in large-scale use cases. Primarily these are agricultural and industrial but if you know of others feel free to make your case.

According to the United States Department of Agriculture, about 80% of all ground and surface water is used in agriculture. I’m not particularly interested in hearing a debate on water rights and the like (there’s a rather interesting article here if you want more on that). The agriculture industry produces food, and employs a lot of people. The conflict is of course long growing season versus lack of water compounded by severe drought. Even if we could move our food production elsewhere it would be a monumental undertaking to also relocate the infrastructure supporting it. Of course we need to look to the future, but can we leverage our engineering prowess now to conserve the water that is being used right now?

Enter with an Idea

Write down your ideas for agricultural and industrial water conservation as a project on Tag the project 2015HackdayPrize. Do this by next Monday and you’re in the running for this week’s awesome prizes.

You aren’t necessarily committing yourself to finishing out the build. At this point we want to get the idea machine rolling. One good idea could spark the breakthrough that makes a real difference in the world.

This Week’s Prizes


We’ll be picking three of the best ideas based on their potential to help alleviate a wide-ranging problem, the innovation shown by the concept, and its feasibility. First place will receive a DSLogic 16-channel Logic Analyzer. Second place will receive a an Adafruit Bluefruit Bluetooth Low Energy sniffer. Third place will receive a Hackaday robot head tee.

The 2015 Hackaday Prize is sponsored by:

Aging in Place Prize Projects that Made us say Wow

The 2015 Hackaday Prize is all about solutions to problems affecting a large number of people, and aging touches everyone. This week we were on the lookout for the entries best addressing the problem of Aging in Place. This means being able to live in your home and community independently and comfortably as one ages. It is as important to the aging as it is to their friends and family; a topic well worth your hacking skills and engineering brilliance.

Monitor Warning Signs

There were several entries that focused on monitoring for out-of-the-ordinary behavior. The Personal Medical Assistant seeks to leverage the sensor array and computing power of smartphones combined with ancillary data harvesting from things like an ECG chest band or a pulse oximeter watch. The idea is to watch for a series of precursors to health emergencies and warn both the person being monitored and their support network of family or caretakers.

The whimsically title Ye Oldie Monitor focuses on a similar idea with a more passive role. The concept suggests a base-station and a series of remote monitors throughout the living area, like PIR motion sensors, to alert for notable variations on a person’s normal day-to-day activities. In a similar vein the LiteHouse project would retrofit the household lighting fixtures with motion detectors. These automatically light each area to help prevent low-light accidents like falls, while also monitoring for signs of duress.

Solving the Communication Barrier

being-thre-with-pi-thumbWatching out for each other is complicated by distance.  We saw a few entries that try to alleviate that, like the Being There with Pi project. Smartphones and computers are a great way to communicate, until you need help making your smartphone or computer work in order to do so. This project looks at developing a dedicated video conferencing system based around the Rasperry Pi. The point is to develop an excruciatingly simple, robust form of live video communications.

julias-speakerphoneContinuing on the note of simplified communications is Julia’s Speakerphone project. [Julia] is living with multiple sclerosis that has resulted in her being bed bound for almost a decade. Making phone calls has been both rare and leaves us wondering why this sort of solution isn’t already in wide adoption. The solution is a combination of a Bluetooth hands-free calling module, Android tablet, Skype a pay-as-you-go cellphone, and an interesting button hack for [Julia] to activate the hand’s free. It is crafted with leaf switches and polymorph and worn as a bracelet. The proof of concept is there and we can’t wait to see this evolve into a more robust and extensible solution.

This Week’s Winners


First place this week goes to the Personal Medical Assistant and will receive a RE:load Pro programmable constant current load.

Second place this week goes to Julia’s Speakerphone and will receive a Sparkfun Microview.

Third place this week goes to Being There with Pi and will receive a Hackaday CRT-android head tee.

Next Week’s Theme

We’ll announce next week’s theme a bit later today. Don’t let that stop you from entering any ideas this collection of entries may have inspired.

The 2015 Hackaday Prize is sponsored by:

Build a Phased-Array Radar in Your Garage that Sees Through Walls

Until recently phased array radar has been very expensive, used only for military applications where the cost of survival weighs in the balance. With the advent of low-cost microwave devices and unconventional architecture phased array radar is now within the reach of the hobbyist and consumer electronics developer. In this post we will review the basics of phased-array radar and show examples of how to make low-cost short-range phased array radar systems — I built the one seen here in my garage! Sense more with more elements by making phase array your next radar project.

Phased array radar

In a previous post the basics of radar were described where a typical radar system is made up of a large parabolic antenna that rotates. The microwave beam projected by this antenna is swept over the horizon as it rotates. Scattered pulses from targets are displayed on a polar display known as a Plan Position Indicator (PPI).

Block diagram of a conventional radar system using a parabolic dish.
Block diagram of a conventional radar system using a parabolic dish.

In a phased array radar (PDF) system an array of antenna elements are used instead of the dish. These elements are phase-coherent, meaning they are all phase-referenced to the same transmitter and receiver. Each element is wired in series with a phase shifter that can be adjusted arbitrarily by the radar’s control system. A beam of microwave energy is focused by applying a phase rotation to each phase shifter. This beam can be directed anywhere within the array’s field of view. To scan the beam rotate the phases of the phase shifters accordingly. Like the rotating parabolic dish, a phased array can scan the horizon but without the use of moving parts.

Continue reading “Build a Phased-Array Radar in Your Garage that Sees Through Walls”