uart

70 Articles

Giving The MSP430 A GUI

October 7, 2012 by 30 Comments

Sometimes you need to toggle or read a few pins on a microcontroller for a project so simple (or so temporary) that coding some firmware is a rather large investment of time. [Jaspreet] had the same problem – wanting to read values and toggle pins without writing any code – so he came up with a rather clever solution to control an MSP430 through a serial connection.

[Jaspreet] calls his project ControlEasy, and it does exactly as advertised: it provides a software interface to control ADC inputs, PWM outputs, and the state of output pins via a desktop computer. ControlEasy does this with a matching piece of code running on any MSP430 with a hardware UART (like the TI Launchpad) sending and receiving data to the computer.

Right now ControlEasy can read analog values, generate PWM output, and set individual pins high and low. [Jaspreet] plans on expanding his software to allow control of LCDs and I2C and SPI devices.

In the video after the break you can see [Jaspreet] fiddling around with some pins on his LaunchPad via the GUI. The software is also available for download if you’d like to try it out, but unfortunately it’s a Windows-only build at this point.

Continue reading “Giving The MSP430 A GUI” →

Getting A Console And Quake II Running On A Raspberry Pi

July 2, 2012 by 14 Comments

Those Raspberry Pi boards are flying into the mailboxes of tinkerers all around the globe, so our tip line is currently awash in a deluge of Raspi hacks. Here’s two that came in over the weekend:

First up is [reefab]’s port of Quake II for the Raspberry Pi. The build is based of Yamagi Quake II and is mostly playable. The Quake III port for the Raspberry Pi is old hat, but we’re happy to relive the pulse-pounding action of Quake II any day.

Next up is [Joonas]’ take on getting a serial console up and running with the Raspi. The Raspberry Pi has a UART serial console on its 26-pin header, but you can’t just connect those pins to a serial port. To shift the +/- 12V down to the 3.3 Volts the Raspi can understand, [Joonas] used a MAX3232 – the 3.3 Volt version of everyone’s favorite RS-232 transceiver. With a breadboard and a couple of caps, it’s easy to connect your Raspi to a serial console. Neat.

Controlling Raspberry Pi Expansion Pins With A Web Interface

May 5, 2012 by 61 Comments

For the lucky few who have a Raspberry Pi board in their hands, you can now use the GPIO pins as a web interface (German, google translation). [Chris] is turning this magical board is turning a small device that can play 1080p video into something that can blink LEDs via the web.

The build started with an example of driving GPIO pins under Linux. [Chris] cobbled together a bit of PHP and Javascript on the Raspberry pi. Whenever he goes to the website hosted on the Pi, he’s greeted with the status and direction of a couple of expansion IO pins.

On a semi-related note, [Tony] is building a GPIO MIDI interface for his Pi. Yes, he could just get a USB to MIDI adapter and call it a day, but this is a far more professional looking solution to all the MIDI goodness the RasPi will deliver. If you’ve got any info on other RasPi breakout boards you’ve seen, send them in on the tip line.

Vintage VT100 Terminal Computing…with A Beaglebone

March 7, 2012 by 25 Comments

decbox

A cool little project came our way, which we thought might be of interest to some of you vintage computer buffs. [Joerg Hoppe] wrote in to share a DEC VT100 terminal he resurrected in a novel fashion.

His “DECBox” system was created with a Beaglebone, which he uses to run a wide array of PDP11/VAX terminal emulators, thanks to the SIMH project. [Joerg] constructed an expansion shield for the Beaglebone that provides several UART connections, enabling him to connect it to his DEC terminal over a serial interface. Since he added several serial plugs to the Beaglebone, he can even run multiple emulator installations in parallel on different terminals without too much trouble.

[Joerg’s] efforts are mainly for a vintage computer display he is constructing, but setting up such a system of your own should be no problem. If you happen to have one (or more) of these boxes sitting around collecting dust, this would be an easy way to get them all up and running without bulky external hardware, since the Beaglebone tucks nicely into the rear expansion slot on a VT100.

Be sure to check out his site for more details on how his DECBox software package works as well as for more pictures of vintage terminal goodness.

AltSoftSerial Looks To Speed Up Arduino Software UART

February 13, 2012 by 42 Comments

So let’s say your using an Arduino in your project. You already have the hardware-based serial interface working with one portion of the project and need a second serial port for unrelated hardware. The obvious solution is to write one in software. But this is a place where working in the Arduino environment gets really hairy. Since there’s a layer of abstraction between the code and the hardware interrupts, it can be difficult to know if you are going to have timing problems. But there’s a new library available which seeks to reduce the latency of software-based serial communications so that you don’t have to worry about it.

It’s named AltSoftSerial because it is a software-based serial library that is an alternative to the NewSoftSerial package. The former can function with just  2-3 microseconds of latency, while the latter has as much as a 174 microsecond hit. If it functions as advertised that’s quite an improvement. It’s not hard to put together a hardware test platform, and the example program is only about a dozen lines of code (which is the beauty of working in this environment) so give it a try if you have a free hour here or there.

Throw Together A Temperature Logger In Minutes

October 18, 2011 by 17 Comments

[Rajendra] found an easy way to make a USB temperature logger. He already had a USB to UART adapter that takes care of the heavy lifting. On one end it’s got the USB plug, on the other a set of pins provide a ground connection, 3.3V and 5V feed, as well as RX/TX lines.

To get the hardware up and running all he needed was something to read a temperature sensor and push that data over the serial connection. An 8-pin microcontroller in the form of a PIC 12F1822 does the trick. It runs off of the 5V pin on the USB-UART, and uses the ADC to get temperature data from an MCP9701A sensor.

The sample rate is hard-coded into to the PIC’s firmware, but adding a button, or coding some serial monitoring could easily make that configurable. [Rajendra] used Processing to write an app which displays the incoming temperature info and uses the computer to time-stamp and log the inputs. We could see this as a quick solution to tracking wort temperature during fermentation to make sure your beer comes out just right.

Getting More Information From Your Battery Charger

July 18, 2011 by 9 Comments

echo_6_battery_charger_serial_hacking

[Dane] bought a reasonably cheap ($17) Hobbyking Echo-6 battery charger and wanted to see what sort of information he could pull from the unit. Since the charger is designed for a variety of battery chemistries and sports an LCD screen, he figured that it contained a fairly decent microcontroller which he could tap into for some useful data.

He disassembled the unit and started looking around for any useful items. He discovered that it used an ATMega32 microcontroller and had quite a few unpopulated areas on the PCB, which led [Dane] to believe that the Echo-6 shared its main board with a more robust charger. He tapped into the ATMega’s UART and began seeing data immediately. Once he figured out what was coming over the serial line, he piped the data into LogView, resulting in some nice graphs showing off the charge/discharge processes in detail.

Tapping into the Echo-6 seems easy enough for any skill level, and we assume that just about anyone would benefit from getting kind of information out of their battery charger.