DIY four channel logic analyzer

Logic analyzers are handy when dealing with multiple channels of digital signals. You may want to find failures in data lines, hack unknown devices and many more. So logic analyzer should place a decent place on your workbench. As logic analyzer isn’t a device for everyday use especially if you have a two channel oscilloscope – buying it shouldn’t be necessary. It is more fun to build one. Here is a pretty low budget logic analyzer built around PIC18F4580 microcontroller.

It has four channels operating at 200Hz to 2MHz sampling frequency. Its voltage input range is up to 5V. Each channel can hold 1024 samples in memory. Traces are displayed on standard 64×128 graphical display. Whole design is powered from standard 9V PP3 battery what makes it handy little device.

Low budget 4/8 channel logic analyzer

Probably logic analyzer isn’t a “must have“tool for most hobbyists. You won’t need it probably at all if you are dealing with simple projects. But if one day you will miss it – don’t rush to buy one. Build one!

If you have a scope on a table – let it do the job. All you need is to build a simple PIC18F26K20 based circuit that takes 4 or 8 logic inputs and converts them to oscilloscope signal. Logic analyzer uses one scope channel and TRIGGER input for triggering display.

NES On-A-Chip – The Embedded System in VHDL

First of all, did you know what VHDL is? For your information, VHDL is commonly known as a design-entry language for field-programmable gate arrays and application-specific integrated circuits in electronic design automation of digital circuits. VHDL is derived from VHSIC hardware description language, where VHSIC stands for “Very-high-speed-integrated circuit”.

Based on the information, VHDL was originally developed at the US Department of Defense. The main purpose of the mission is to document the behavior of the ASICs that supplier companies were including in equipment. This means, VHDL was developed as an alternative to huge, complex manuals, which were subject to implementation-specific details.

Original_FPGA_Interface

Well, this NES On-A-Chip’s main goal is to implement an older embedded system entirely in VHDL. In this case, you might want to choose the NES, as its complexity and variety of subsystems. The whole idea is to prove that chips can be modeled in VHDL and synthesized on an FPGA. Furthermore, it can be used to replace, either single ICs in old systems or the systems themselves.

You have to prepare the Altera UP3 development board to implement the design. In addition, you must use an Intronix LogicPort USB logic analyzer as well.

The 32 Channel Logic Analyzer

You’re working in the electronic field that require you to observe and check out the digital system with precision, but you didn’t know the proper way to build it? If you’re having the difficulty, then today’s your lucky day, as we’re going to develop a 32 Channel Logic Analyzer!

For those who never get in touch with logic analyzer before, it is an electronic instrument displays signals in a digital circuit. Practically, they’re used for capturing data in systems, which is having too many channels to be examined with an oscilloscope. The software that running on the logic analyzer can be used to convert the captured data into timing diagrams, protocol decodes, assembly language and much more.

The 32 Channel Logic Analyzer

For your information, the logic analyzer that we’re building today is a 32 channels with 4K sample memory up to 100HMz and 16 channels up to 200MHz. Beside that, it included Java client application and allows waveform exploration (As well as SPI and I2C protocol analysis). The project has been optimized, so that it can run on the Butterfly Platform hardware without problem.

The logic analyzer is building on a FPGA technology, but it has the downfall, where it can only sample 1.2V, 2.5V and 3.3V. Hence, please keep in mind that any higher voltages can damage the input pins of the FPGA!

The Marvelous Mega Meter

You can’t get enough with the current electronic bench test instrument and you’re wishing for a more powerful multifunction bench tester? Then, you’re the lucky person, as today you’ll have the chance to look into this Multifunctional “Mega Meter”…

For your information, this Mega Meter is based on an ATMega128, where the microcontroller programming is fully done under GCC 3.2 and the PC interface was being programmed by using VB 6.

mega-meter

If you refer to the above figure, you can see that there are many electronic components have been used here, such as:

  1. Two 0-10 VDC voltmeters (The basic ADC inputs),
  2. A 0 – 30 VDC Hi-Z autoranging voltmeter with x10 jumper to give 0 -300 VDC range,
  3. A 0 – 3 Amps high side ammeter,
  4. 4 channel logic analyzer,
  5. Frequency generator (The frequency can be adjusted by modifying the value in OCR1A),
  6. Frequency counter (It uses 16 bit TCNT3 in external clock mode to count incoming pulses),
  7. Waveform generator that based on a MAX038.

Beside that, the board also includes the RS-232 interface, ISP interface, 14.7 MHz crystal, 5V supply and much more. However, all the included functions can be implemented on lower level devices, although it’s not at the same time! This Mega Meter is what you’re looking for, so don’t waste your time anymore. It’s time to kickstart the project right now…

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