The AD is a chip that can produce a sinusoidal wave from about 1hz to 40mhz.
AD9850 DDS VFO
Without going into too much detail you are required to send a set of serial or parallel data to the chip to set the frequency. However it has been hard to find a good AD Pinout so here you go. For me, the easiest way to manage the AD is with an Arduino Uno. I have been playing with the Arduino for only a couple of months and I already have found it to be a fantastic development platform.
A little quick work with a protoboard and I have a nice working VFO. You can watch my video on YouTube showing how it works. I also have another video of the VFO attached to my oscilloscope. This project is ongoing. You should be able to deduce the pin outs on all items from the Arduino Sketch but if you have questions just contact me.
My schematic is a little rough as I do not tend to create them that often so let me know if you catch anything out-of-place! Because of a lot of requests I have also created a version for IF superhet type receivers. The IF can be anything you wish and can be additive or subtractive.
The code is well documented and for those of you who modified my original sketch it should be easy enough to adapt as you see fit. If you build something from my design please send me a picture or a video of your creation. I love to see what others do! I will need some kind of amp to bump up the output to 4v ptp, manual calls for 12v on 15 meter band for some reason. Anyhow I like what you have here and let me know what you think. Typically 1v or. I built This VFO and it works great.
If you need more power try this site. The main difference is going to be the Interrupt pins. Yes, it will work with nano. I build it. You mentioned that when using a Nano, connect to data not d7 on the dds module.
I see D0-D7.Add the following snippet to your HTML:. Inexpensive to build but a very useful tool for every electronics laboratory. Project tutorial by Mirko Pavleski. Please log in or sign up to comment. Arduino TEA radio with analog meters for showing frequency and signal strength.
The soldering iron controller based on arduino that implements PID method to keep the temperature of the iron. This tutorial will show you how to control servo motor using Arduino Nano and an easy to use Servo motor driver.
Project tutorial by Jithin Sanal. When a Nerf gun doesn't have a scope, add a movable one with an Arduino and a servo!Подробно о синтезаторе v. 2.0
Project tutorial by Michael Darby - Reactor. This project will show you how to transmit variables to control a servo motor. A small device that will help you sorting resistors without wasting time with their color code. Project tutorial by Federico Vivaldi. Sign In. My dashboard Add project. Project tutorial. Soldering iron generic. Arduino IDE. Must be interrupt pins. This only loads once. To force load again see ForceFreq variable below.
You can make 'slight' tuning variations here by adjusting the clock frequency. Yes, it's cheating but it works! Author Mirko Pavleski 47 projects followers Follow.
Respect project.I wanted to further save some cost and build it using a bare AtmegaP chip, where Pravin had been a great help. I used this diagram for reference. Burn the sketch to a bare AtmegaP IC and build the circuit. My dongle seems to be a couple of KHz off the frequency :and the DDS works just as it is intended! Do let me know how you find this circuitor if you have any questions or suggestions to improve this design, leave your comments below.
But, now a days the world has become digital with precise commercial equipments. Mechanical vfo dont stand a chance, even the 50hz shift is pointed out by others. I mounted your dds vfo works up to 44Mhz at the D7 output as verified on the frequency meter. Can you help solve the problem? I am Brazilian and my English is from Google. Your email address will not be published.
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Amogh Desai. He uses this blog to share his views and ideas with people sharing similar interests. GR8 project. Leave a Reply Cancel reply Your email address will not be published.This was a remarkably simple build experience! The key is the si… three clocks, MHz, all software controlled, in a tiny 10 pin MSOP package, and all for a few dollars. With the wide range of Arduino breakouts, all sorts of control and monitoring behaviours now become possible — GPS, SWR, power and temperature monitoring for power amplifier stages or linears, sequencing, switching, wifi, bluetooth, packet data links, to name a few.
Once you have control of the VFO and BFO in software, controlling other things in a transceiver like band, memories or multiple VFOs, IF filter switching is all just a matter of a few more lines of code. I came up with the following additional controls:. A more contemporary way of achieving the same thing is to use a 1-of decoder driven by I2C. Something like this break-out expander. Or this IO expander.
That means 4 Arduino digital outputs are necessary to convert 4 bit data values to the display, plus 2 control lines. A common way around this without going to the added complexity of IO expander break-outs is to multiplex a number of pushbuttons switching on a resistive voltage divider, on a single analog input. The script reads the pin and interprets a voltage range for each button. I built a rack of 6 momentary on switches on a receiver front panel I prefer pushing down on a spring loaded switch over pushing in on a pushbutton.
The values I got were quite predictable and narrow in range. In the mapping script I used wide number ranges to allow for DC supply variations or drift. The si clock outputs are square waves. There is some discussion in the forums about the harmonic content of the waveform and the need for low pass filtering. The answer is, it depends on what you are doing with the VFO signal. In the dual conversion multiband receiver I have in mind, all 3 mixers are SBL-1s. I decided that low pass filtering was desirable, and plan to add a 5 element Chebychev LPF and a broad-band 2N amplifier stage on at least the VFO clock.
Experimenters are using Arduino analog inputs with simple external circuitry to implement the following meters in transceiver projects:. The post describing the VFO is here. A video of the new rig receiver only at this stage is here. Further details in the readme and main file header.
Welcome to the world of digital electronics! There are a number of VFO kits out there now too using this synthesizer. You can do an awful lot with microprocessors in rig control and still use analog for the signal chain. Like Like. Thanks David. Its pretty good here on the dark side of digital electronics! I can see a steady trajectory in my projects from s radio craft. I can see the day when i do design one off PCBs with surface mount components, mainly to reduce size for portable rigs.
Thanks for your Likes and comments David! Nice project Paul. Thanks for your comment Ardy, looks like you are a keen operator, I spend too much of my shack time soldering to operate much! Hello Paul.The si is on an Adafruit breakout which includes a 3. The base is Veroboard. The sockets are for the Nano, si breakout and two more for the rows of digital and analogue pins that will sense or control rig functions.
Another pair underneath the board socket the LCD. This sandwich arrangement seems to be favoured by a number of designers. Raduino, for example. I used one of the optical encoders from Minikits for the second time. These are high quality pieces with great bearings and a light feel.
The 45mm Collet Knob is also from Minikits. The encoder is a lot larger and heavier than the small cheap mechanical ones found in most VFO kits, but the tuning feel is comparable to many of the commercial transceivers I have used. It is a small luxury in a homebrew rig that adds to the pleasure of use.
I made up a mounting bracket of aluminium right angle stock for the display, board and the encoder. This makes the VFO module self contained. The completed assembly can be dropped into the radio case and bolted in a minute. I think this is a fair trade-off. Why not just buy a Raduino?
Is there anything about my hand-built unit that differs from Raduino?
DDS VFO demo Using AD9850 and Atmega328P
Further, I spent around 12 hours noodling, sketching, soldering and debugging. It all comes down to how you want to spend your valuable hobby time. If that is scratch-building everything, making a radio with your own bare hands, from the ground up, then hand craft everything and enjoy! My enjoyment comes from building and then operating a variety of simple and not-so-simple transceivers. The SOTA summits are always calling.
The OLEDs are a superior display. The colour screens can mimic high-end commercial transceiver displays. I purchased an OLED last year and blew it up by using a dodgy regulator.
That experience aside, I am not jumping on the OLED bandwagon, mainly because the tiny size of the displays which are completely out of scale with the rest of the rigs that we thru-hole scratch-builders turn out. A homemade 6 inch wide by 2 inch high front panel sporting a 1. Love your work Jerry!See the Shop page for pricing and availability. Simple to operate using a single rotary encoder control with press button switch. Bright 16 character by 2 line LCD display. Can also be used with a non-backlight display to reduce current consumption if needed.
Output frequency range of 10KHz to 10MHz. RIT control allows fine adjustment of receive frequency without affecting the transmit frequency. Display of power supply voltage. Programmable IF frequencies. Separate high and low side IF frequencies ensure the displayed frequency is the same as the transmitted frequency when changing sidebands. Programmable option to save the current frequency and step value into memory.
These are re-loaded at power up. Fine adjustment of frequency in configuration to allow for master clock tolerances. Voltage display can be trimmed in configuration to allow for voltage reference tolerance. Can be configured without an IF Offset to allow use as a signal generator or with Direct Conversion transceivers.
Draws only around 50mA at Spurious outputs at least dB. Typically mV pk-pk sine wave output ohms. High quality double sided PCB with ground plane, plated through holes, solder mask and silk screen. Simple and easy to build using through hole components apart from one SMD chip.It's all in one, easy to use spot. We are a Fortune 500 company that used to use Act-On, but found it inadequate and dated for our needs. Our many different businesses use HubSpot differently, but all of the businesses rely on HubSpot for email marketing and landing pages.
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