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Picture of Analog Experiments Anywhere
Two DIY micro-controller based USB connected electronic units which along with the Texas Instruments Analog System Lab Starter kit and a laptop permit you to conduct analog experiments anywhere.

It would be wonderful  if senior students and laboratory supervisors built these units so that they could be used in their laboratories by freshers.




Aj-SigGen-PS     http://ajoyraman.in/DDS_SigGen_PS.html

Aj-Simple-Scope      http://ajoyraman.in/USB_Simple_Oscilloscope.html

Analog System Lab Starter Kit ASLKv2010    http://www.uniti.in/teaching-material/analog-system-lab-starter-kit
 
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Step 1: Aj-SigGen-PS

Picture of Aj-SigGen-PS
This unit is designed to compliment the Aj-Simple-Scope and serve as a teaching aid for budding engineers, electronic enthusiasts and hobbyists.

This USB connected unit implements a microcontroller based DDS Signal Generator providing Sin and Triangular waveforms with adjustable magnitude and offset up to 50 kHz. TTL and 1 V square waves are simultaneously provided. Additionally ± 12V and a variable +2 to 7V output with a total capacity of  1W is provided to power external circuits under test.


Step 2: Block Schematic and Function Description of Signal Generator and Power Supply Unit

Picture of Block Schematic and Function Description of Signal Generator and Power Supply Unit
 For ease of portability the unit is powered and controlled from the USB port of a PC.


Two PIC18F14K50 microcontrollers are used to provide the functionality of the unit.

The first PIC microcontroller implements the following functions:

• Communicates with the host PC for enumeration as a USB to UART device

• Sets up the unit as a 500mA device

• Switches on power to the DC-DC converter

• Provides the complimentary square wave drive to the DC-DC converter

• Acts as a USB communication interface to the second PIC

• Provides the Amplitude reference for DAC2

• Provides the digital word for DAC1 giving the offset value.


The second PIC microcontroller implements the remaining DDS functions

• Direct Digital Synthesis (DDS) signal generation

• Sin/ triangle word output to DAC2

• TTL and 1 V square reference output


The DC-DC converter is a driven 1W, 5V to ± 12V operating at 100 kHz. The +12 V output is fed to a linear regulator to provide a variable +2 to 7 V output controlled by a variable potentiometer.

The DC-DC converter provides full protection to the host PC USB port as its outputs are short circuit and current limit protected.

The circuit under test can be rigged up on a standard breadboard and powered from the power sockets provided.

Step 3: Aj-Simple-Scope

Picture of Aj-Simple-Scope
This unit is designed to compliment the Aj-SigGen-PS and serve as a teaching aid for budding engineers, electronic enthusiasts and hobbyists.

This USB connected unit implements a microcontroller based 2-Channel Oscilloscope providing continuous sampling rates up to 100 ksps and 20 Msps using equivalent time sampling. Common DSO features such as spectrum analysis, waveform capture and data saving are provided. The input range is ± 12V with additional gain settings of X2 and X5. Trigger and sweep options are also provided.

Step 4: Block Schematic and Function Description of the Simple-Scope Unit

Picture of Block Schematic and Function Description of the Simple-Scope Unit
For ease of portability the unit is powered and controlled from the USB port of a PC.


A PIC18F14K50 and dsPIC30F4011 microcontrollers are used to provide the functionality of the unit.

The first PIC microcontroller implements the following functions:

• Communicates with the host PC for enumeration as a USB to UART device

• Sets up the unit as a 200mA device

• Switches on power to the DC-DC converter

• Acts as a USB communication interface to the second PIC


The second PIC microcontroller implements the main Oscilloscope Functions

• Analog to Digital conversion of the CH1 and CH2 signal conditioned inputs at the required sampling rates

• Trigger interrupt handling

• Responding to serial commands from PIC1 and sending back the acquired data.

• A  Busy signal is  also generated


The dual-charge pump circuitry of the MAX232 is used as a DC-DC converter to provide a nominal ± 10V to all the analog circuitry.

Step 5: Typical Test Results Using the ASLK

Refer to the Analog Systems Lab Manual from Texas Instruments

http://www.uniti.in/images/teaching-material/aslk-lab-manual-2edition.pdf

It is extremely easy to setup the analog experiments in the lab manual on the kit and test them using the Aj-SigGen-PS and Aj-Simple-Scope units.

The kit is powered from the Aj-SigGen-PS which also provides test signal inputs as required. The wave-forms at selected test points on the circuits are captured using the Aj-Simple-Scope and saved as image files on the laptop.

Typical wave-forms which have been captured are shown.

These demonstrate the capabilities of the ASLK and how to test the circuits using the two DIY units presented here.

For further details of the Hardware and freely downloadable Software kindly visit http://www.ajoyraman.in


apizano2 years ago
Hi Ajoy – I work for TI in Worldwide University Relations, and must say that our entire team truly enjoyed your Instructable! On a personal note, I was very impressed with your project’s innovation, your engineering expertise, and the driving passion you have to help students learn.

That said, I’d love to invite you to be a guest blogger on TI’s University Blog to continue the conversation about your experience with our Analog System Lab Starter Kit. Please also feel free to visit our E2E community forum and comment on the ASLK PRO or ASLK starter kit tool folder pages. Your input would be highly valued!

If I may, I would also like to add a comment about our other Analog kit that is available worldwide: the Analog System Lab Kit PRO (ASLK PRO). It is the perfect platform to test almost any analog system using general-purpose ICs such as op-amps and analog multipliers.

Are you familiar with this product? It comes with 14 step-by-step experiments. In fact, if the ASLK PRO kit would be helpful to you as you continue investing in your hands-on student learning endeavors, we would like to talk to you about this as well.

I hope to hear from you soon regarding the invite to post on the guest blog and chat further. Please message me initially through Instructables.

Best,

Amber Pizano
Texas Instruments Incorporated
ajoyraman (author)  apizano2 years ago
Thank you for your encouraging comment ! I must acknowledge the interactions with uniTI, Bangalore, India which have have helped in focusing my efforts. Best Regards, Ajoy
Outstanding.