One tool that I’ve been missing at my lab at home is function generator. They tend to be a bit expensive, so I haven’t bought one. I thought this might be a good opportunity to try and make one myself. I found a pretty common DDS (direct digital synthesis) chip, called AD9833. Then just strap a USB-enabled AVR micro there and maybe some analog electronics.
This board doesn’t do any of the special analog magic to allow for variable amplitude or offset for the signal. The output is fixed to 0-4v. I’m planning to make another completely analog board for adjusting amplitude and offset.
AD9833 – based USB Function Generator - [Link]
AKTAKOM’S AWG-4151is the latest in the series of innovative waveform generators
Miami Fl., July 27, 2012 – T&M Atlantic., distributer of the test and measurement equipment, today unveiled Aktakom AWG-4151 150 MHz single-channel digital generator.
This generator was designed using the technology of direct digital synthesis (DDS) based on 14-bit DAC and is distinguished by high functionality and specifications. The new model of AKTAKOM AWG-4151 generator has maximum oscillation frequency up to 150 MHz (for a sine wave) at the maximum frequency resolution of 1 Hz. In addition to a sine signal, AWG-4151 can generate such standard signals like square wave, pulse, noise and user signals with a frequency range from 1 µHz to 10 MHz: rising and falling exponentially, Sin (x)/x and DC signal. In addition the new AWG-4151 generator allows users create and save arbitrary shape signals into the internal memory.
AKTAKOM AWG-4151 universal generator can work not only with harmonic signals, but also has modulation opportunities and other special modes including: amplitude modulation (AM), frequency modulation (FM), phase modulation (FM), frequency-shift keying (FSK), and also operation in pulse width modulation (PWM), sweep mode, frequency and pulse bursts.
For the majority of new AKTAKOM generator models it has become traditional to use a color graphic display to display a signal waveform. The same can be seen in AKTAKOM AWG-4151 generator with color (65536 colors), 3.9 inch LCD with TFT matrix and resolution of 480×320 pixels. The use of a color graphic display simplifies users’ operation process making a generator control simple and clear. Also it helps to see a currently specified value not only in digital form but also to understand what it’s responsible for on a displayed signal form.
More info available at www.tmatlantic.com
Universal Digital Arbitrary Waveform Generator - [Link]
Well, our meetings take place on wednesdays at 10:30 (sharp). A radio controlled clock is used to determine whether you are late (and must bring a cake next time) or not. Unfortunately the identical radio controlled clock in my office always shows a different time
After baking a lot of cakes, I thought about synchronising these disreputable clocks …
Homebrew DCF-77 Signal Generator - [Link]
Having done half a dozen V-USB tutorials I decided it’s time to whip up something cool. As USB keyboards were an area untouched, I decided to make a small USB HID keyboard device that types a password stored in EEPROM every time it’s attached. A new password can be generated just by tabbing CAPS LOCK a few times (4 times to start password regeneration and one tab for each password character generated, 10 is the default password length)
DIY USB password generator - [Link]
Dilshan developed a 8 channel USB digital signal generator and an open source Windows application called Kidgo Player to drive it. The hardware is basically just a PIC18F2550 USB breakout board used to provide 8 digital outputs for his software. The Kidgo Player’s source is available on GitHub, and has the following features – [via]
- Save waveforms and settings as binary file (KDF file) or export waveform as a text file
- Playback controls such as “Play to segment”, “Play from segment”, “Step back”, “Step next” and “Clear”
- Shifting and rotating waveforms
- Invert, Reset, Clocking and Binary Generator functions
- Copy and Paste waveforms
- Mute function to each individual channel
- Launch without any installation or configuration (design to work as portable Windows application)
Kidogo: 8 channel USB Digital Signal Injector - [Link]
Sergei Bezrukov writes:
This project is based on the Function Generator described on Mondo Technology web site. I just did very slight changes and fixed some obvious typos in schematic. The code is rewritten for the Microchip MPLAB IDE syntax.
- Frequency range: 11Hz – 60KHz
- Digital frequency adjustment with 3 different steps
- Signal forms: sine, triangle, square, pulses, burst, sweep, noise
- Output range: ±15V for sine and triangle, 0-5V for others
- Sync output for pulses
The device is powered from 12VAC which provides a sufficiently high (over 18V) DC voltage needed for a normal operation of 78L15 and 79L15. The 12V power supplies are replaced with 15V ones. This is done in order to LF353 Op-amp could output the full range of signals to a 1K load. By using a ±12V supply this resistor must be at least 3K.
60kHz PIC Function Generator - [Link]
Charalampos Andrianakis writes:
When i was using operational amplifiers at school lab i wanted a function generator at home to play with and work on circuits with Op Amps for better understanding. So i found on the internet a free function generator circuit which uses the IC XR-2206, i printed the PCB with my UV epxosure box, i bought an enclosure box, i put everyhting inside and here is the result.
The function generator can generate Square, TTL, Sine and Triangle waveforms from 1Hz to ~1Mhz with Voltage regulation to Square Sine and Triangle waveforms.
XR-2206 Function Generator - [Link]
Here is my homemade function generator that can produce a square, triangle, and sign wave. This is all done with a few bucks worth of parts. The heart of the function generator is a LM324N quad OpAmp. I got the schematic off of a site where they were also selling kits to build the signal generator.
DIY Function (Signal) Generator – [Link]
This project didn’t look complicated but it was. The MCU part is really simple: just some code for the Display, Keypad and DDS Communication.
A DDS is a chip that is driven by a hi-frequency oscillator. I used a 50 Mhz clock. Inside this IC there is a big divider that goes down to less than 1Hz. The resulting clock is passed to another counter which is connected to a Sine ROM table. If you need a triangle wave, the counter is directly connected to the output.
Function Generator – [Link]
In this video, we’re demonstrating how to measure component signatures using a digital storage oscilloscope, signal generator, and a solderless breadboard.
How to Use an Oscilloscope and Signal Generator as a Component Tester / Curve Tracer – [Link]