Jon Titus Blog

Titus regularly contributes articles on electronics and measurement. He has extensive experience designing with microprocessors and microcontrollers, and developed data-acquisition and instrument-control systems and taught many courses on software and hardware design. A recipient of the George R. Stibitz Computer & Communications Pioneer Award, he holds a BS from Worcester Polytechnic Institute, an MS from Rensselaer Polytechnic Institute, and a PhD from Virginia Polytechnic Institute.


Monday, February 8, 2010

One Extra Component and Two Dumb Mistakes

Feb 8 2010 11:34AM | Permalink | Email this | Comments (3) |

I breadboarded a microphone pre-amplifier circuit and it worked well until I added a circuit that used the audio output to drive an LED bar-graph display. Now, as the LEDs turned on or off, I could hear a click on the audio output. The audio and bar-graph circuits had plenty of decoupling capacitors, and I had used short connections, so coupling of the digital switching signal into the audio circuit seemed unlikely. My wife got tired of hearing me repeat "Test 1 2 3, test 1 2 3..," so I disconnected the microphone's output signal and fed the preamp directly with a low-frequency triangular wave that exercised the bar-graph display. Now I could hear the clicks without talking. Still I couldn't find their source.

But I had reviewed only the audio portion of the circuit and overlooked the +5V power for the LEDs that also supplied the bias current for the electre...Read More

 


Related entries in: Audio | DEV-monkey | EMI | Power Supply Noise | 


Tuesday, February 2, 2010

A Cool Tool for Remote Serial-Port Control

Feb 2 2010 4:46PM | Permalink | Email this | Comments (1) |

Ed Sutter, the fellow who created MicroMonitor (uMon), an open-source embedded-system boot platform, sent me a note about his newest software, uCon, an embedded system console. Although many people think of serial ports as old fashioned, or even dead, those involved with embedded systems consider them much alive and useful.

To help developers take better advantage of serial ports, Ed's uCon acts like a terminal emulator that also works with remote networked computers, or "backends," to let them connect with a development system or prototype as a telnet or ssh client.

According to Sutter, uCon can operate as a telnet server on a host PC and then let remote clients connect to the PC and virtually connect to the same COM port that the local uCon session has connected to. This technique lets a developer or engineer work locally with a development system thro...Read More

 


Related entries in: Code development & Debugging | Debugging | DEV-monkey | Embedded Design Software | Innovators | 


Monday, January 25, 2010

Why is Programming So Primitive?

Jan 25 2010 9:34AM | Permalink | Email this | Comments (38) |

I learned to program when I took a course on FORTRAN II in the mid '60's. My college friends and I punched cards, put them in small mailboxes in the computer room, and came back a day later to pick up results--usually error reports.

In over forty years the major programming change I see amounts to getting error messages faster. We still type code a line at a time and we still use a low-level language such as C/C++.  The intellectual property (IP) you license for an FPGA design might as well come on punched cards as in a listing or as hooks to connect to your own VHLD or Verilog code. The same goes for open-source code. It's all so primitive.


"What the heck is 'WRITE OUTPUT TAPE?'"  Courtesy of IBM.

Consider for a moment how we design multilayer ...Read More

 


Related entries in: Debugging | Design Methodology | DEV-monkey | Programming Languages | Simulation | Software Engineering | 


Wednesday, January 20, 2010

Don't Skimp on Product Details

Jan 20 2010 4:03PM | Permalink | Email this | Comments (1) |

An old economist gave some sage advice to a young grad student. "Son," he said, "give people numbers and dates, but never both at the same time." Information from many manufacturers must come from economists-turned-marketers because it often lacks important details.

Here's a case in point, with names removed to protect the guilty. I received a press release about new measurement devices. The release contained almost as much information about the company as about the new products. And the release came with no link to a product data sheet and no block diagram or photograph.

I asked for and received a link to a 2-page data sheet, but it lacked critical information such as the size and voltage of the battery used as an optional power source. Although the data sheet explained users can "configure" the device in several ways, it doesn't ex...Read More

 


Related entries in: Design Engineering | DEV-monkey | Electronics Systems | Marketing | 


Monday, January 11, 2010

Cameras as Debug Tools, and the Gerber Ruler

Jan 11 2010 11:49AM | Permalink | Email this | Comments (9) |

I started to work with some new FPGA-design software that seemed to take a long time to "build" a simple LED-flasher demonstration project. I let it run for about 45 minutes while I answered emails and had a conference call.

When I took another look, I saw something flash in the corner of the software's display area, but it appeared only briefly every 15 seconds or so. That made it impossible to see what the short message said. The message also appeared superimposed on other information, which increased the difficulty to read it.

That's when I thought about using my camcorder to record the display so I could play it back and see what the message said. I recorded about 15 seconds of video, loaded the video into my iMac's iMovie software and slowly scanned through the frames. Then I saw the brief superimposed image of "Scanning JTag ports..."...Read More

 


Related entries in: Board & Subsystem Test | Programmable Logic Design | Software Engineering | 


Tuesday, January 5, 2010

Who Forgot the UAV Video Security?

Jan 5 2010 10:21AM | Permalink | Email this | Comments (18) |

In mid December 2009, headlines such as "Insurgents Hack U.S. Drones" and "Pentagon: Insurgents Intercepted Drone Spy Videos," appeared in newspapers and on Web sites. Stories suggested US military people knew others could intercept the video streams from unmanned aerial vehicles (UAVs) and view them. Apparently insurgents in Iraq--perhaps with help from Iranians--used the SkyGrabber software that, according to the SkySoftware Web site, "... accepts free to air (FTA) satellite data (movie, music, pictures) and saves information in your hard disk. So, you'll get new movie, best music and funny pictures for free." You'll need a satellite receiver or dish-TV system to get the signals. The software costs 21 Euros, or about $US 30. Sounds like a bargain.

Today, developers must create a complete security plan for a new product from the outset. Th...Read More

 


Related entries in: DEV-monkey | Encryption and security | Security Applications | 


Monday, December 21, 2009

Silicon Labs' 8051 Pushes Power Performance

Dec 21 2009 9:36AM | Permalink | Email this | Comments (3) |

I hesitate to guess how many 8051-based MCUs go into products every day. This MCU architecture lives on in many forms. Silicon Labs has good news for 8051 aficionados. The latest low-power C8051F91x/0x MCUs can greatly increase battery life in RFID tags, remote sensors, healthcare devices, wireless controls, and other power-sensitive equipment. According to the company's 14 December 2009 announcement, these MCUs offer the lowest active-mode current at 160 μA/MHz. Current drops to 300 nA in sleep mode (with an active real-time clock and brown-out-detect circuit) or to 10 nA without these circuit powered.


Silicon Labs C8051F912 development kit ($US 99).

When designers look at low-power sleep or standby modes for MCUs, they might forget to also determ...Read More

 


Tuesday, December 15, 2009

What the Heck is Wavenis?

Dec 15 2009 5:16PM | Permalink | Email this | Comments (4) |

A recent announcement explained that Essensium, a Belgian supplier of system-on-a-chip ICs joined the Wavenis Open Standard Alliance (Wavenis-OSA). I hadn't heard of Wavenis, so I investigated. A company called Coronis developed the Wavenis technology for low-power long-distance wireless communications between machines such as remote monitors and controllers. In June 2008, Coronis gave the Wavenis specs to the Wavenis-OSA that now manages standardization activities for the royalty-free technology. The largest Wavenis network covers 100,000 nodes and several million sub-GHz RF transceivers now operate throughout the world. (Technically, the core Wavenis technology is royalty free. Companies can license Wavenis IP that goes beyond the MAC and PHY layers.)

You can find the Wavenis OSA at: ...Read More

 


Related entries in: Communications Engineering | Electronics Systems | Intellectual Property | Technical Standards | 


Wednesday, December 9, 2009

Apply for This Engineer's Dream Job

Dec 9 2009 9:17AM | Permalink | Email this | Comments (20) |

Today's Wall Street Journal (9 December 2009) included a classified ad for the position of National Science Center Director.  The ad's information follows:

An opportunity to lead the most unique business organization in the Department of the Army.  Formulate the strategic vision, with emphasis on growing the business to deliver educational products that support Science, Technology, Engineering and Mathematics.  Responsible for assessing the NSC's strategic direction, leading the execution of strategy, building the teams and programs to support growth.

For details on how to apply, go to: www.cpol.army.mil.  Click on "employment" then "search for jobs" then go to the bottom of the page & enter Job Announcement: SCDZ09608594D1.

I followed these instructi...Read More

 


Monday, November 30, 2009

An MSP430 MCU Dev Kit You Can Wear

Nov 30 2009 10:35AM | Permalink | Email this | Comments (6) |

Yes, you can wear the eZ430-Chronos development kit Texas Instruments introduced on November 23, 2009. The kit looks like, and works like, a sports watch that includes functions for temperature and altitude, and by using an external wireless sensor, heart rate, distance, speed, and calories burned. Users also can take advantage of the built-in RF link to control external actions--such as change PowerPoint slides or operate remote equipment via buttons on the watch case. The eZ430-Chronos costs only $US 49, so even if you want only a neat sports watch, this product looks like a steal. (Order the eZ430-Chronos-915, the 915-MHz version--from the TI Store at www.ti-estore.com. The eZ430-Chronos comes in versions for the 433-, 868- and 915-MHz bands.) For general information and links to hardware and software, visit: ...Read More

 


Related entries in: DEV-monkey | Home Network | Microcontroller | Silicon | 





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