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USB connected TI TMS320F28027 based ZRLC Tweezers with

Most Digital multi-meters measure Resistance and Capacitance and LC-meters can measure Inductance and Capacitance. Presented here is a ZRLC meter which can measure Resistance, Capacitance, Inductance and Complex Impedance.

The hardware is built around a TMS320F28027 micro-controller an 8-port-analog-switch ADG714 from analog-devices and a Microchip rail-to-rail dual operational-amplifier MCP6022.

The hardware details, .Hex file for the TMS320F28027 micro-controller and the VS2013 .Net 2.0 files for the PC GUI are provided in this Instructable.

The Source-Code ( TI CCS5.5 C-Code and VS2013 VB.Net-Code) is shared at the GitHub repository: https://github.com/ajoyraman/Aj_ZRLC_Tweezers .

A manual Impedance mode permits experiments and teaching of magnitude, phase and complex impedance concepts.

This hardware will form an invaluable tool for electronics students and hobbyists working with SMD components.



It should be possible to build this unit for less than $ 25.0

Step 1: Principle of Operation

This application is based on the principle of measuring the voltage (amplitude and phase) across an unknown Impedance when fed a sin-wave of known frequency and amplitude through a known resistance.

The hardware is built around a TMS320F28027 micro-controller an 8-port-analogue-switch ADG714 from analogue devices and a Microchip rail-to-rail dual operational-amplifier MCP6022.

A High-Frequency PWM waveform is generated in the micro-controller and modulated by a 64-Bit sin-wave sequence. This when filtered and buffered forms a sin-wave source ( select able 300Hz, 3kHz, 30kHz). The sin-wave source is connected to one of 4-resistors (100, 1k, 10k, 100k) using the analogue-switch. The selected resistor being connected to the unknown Impedance whose second terminal is connected to ground.

Once a frequency and resistance have been set the sin-wave is generated on command and 128 10-Bit samples of Vout (signal-source) and Vin (Voltage at unknown Impedance) are A/D converted and stored in internal memory.

This data is transferred to a PC through an USB port using an USB-to-TTL converter, which also powers the hardware.

Suitable digital-signal-processing on the PC using the VS2103 GUI software displays the real and imaginary part of the unknown Impedance. This is interpreted as Resistance, Capacitance, Inductance or Complex Impedance.

<p>Very cool. Beautiful tester!</p>
<p>Thank you for sharing your excellent design. Your scheme provides a multi-function meter without need in a PC for GUI. I am also impressed with your other projects and will study them in detail. </p>
<p>Hey</p><p>If you are interested in PCBs made with Kicad (looks like Eagle-level functionality but not limited) it also displays a 3D view of the circuit you have achieved and you can create your 3D Fi separates Wings3D thanks to software that is also free.</p><p>Here is the link to Kicad:</p><p>http://www.kicad-pcb.org/display/KICAD/KiCad+EDA+Software+Suite</p><p>the community also created no components to enrich the original library Kicad here is the link:</p><p><a href="http://www.kicadlib.org/" rel="nofollow">http://www.kicadlib.org/</a></p><p>the bottom of the page there is complete realization of a PCB which I did a few years there is a logic probe very simple but very functional,</p><p>Logic probe is &quot;Vampire&quot; by Mic **.</p>
Thanks Mic100, I also saw your POLLED VAMPIRE PROJECT, great! I currently use a mix of Eagle, Orcad and DesignSpark for my PCB's. I'll consider KICAD for the next project with 3D visualization.
<p>Hey</p><p>I know only the free version of Eagle, it is very efficient Kicad I use for 3D is very precise, Wings3D allows for very fine components when well mastered, you can look at this link:</p><p>http://smisioto.no-ip.org/elettronica/kicad/kicad-en.htm</p>
<p>GreatJob very useful, </p><p>Thank You :)</p><p>I also made a probe of this kind whose author is Heli website is in Spanish, but you can download the project full (PCB made with Eagle)</p><p><a href="http://heli.xbot.es/?p=40" rel="nofollow">http://heli.xbot.es/?p=40</a></p><p>on my link in the project is made with Kicad and I translated the documentation in </p><p>English and French.</p><p><a href="http://1drv.ms/1mEdoZc" rel="nofollow">http://1drv.ms/1mEdoZc</a></p><p>the bottom of the page there SuperProbePIC16F870 2 file (this is the super simple probe) and SuperProbePlusPIC16F876 is most useful I attached the screenshot in Kicad of SuperProbePlus</p>
Nice idea!!!
Smart idea! I really like this project. Thanks for shearig :)
<p>Awesome make ! Thanks for sharing !</p>
<p>Very cool!!</p>

About This Instructable

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Bio: I am a retired Electronic Systems Engineer now pursuing my hobbies full time. I share what I do especially with the world wide student community.
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