The adcinterrupt routine is called by the analog to digital converter each time a conversion is finished and the results are available. The main category is ham radio arduino projects that is about arduino projects for ham radio applications. I got hold of an ad8307 in smd form, too small for me. The power detector is an analog devices ad8307 along with a 50ohm input load. Besides i have modified the software, i removed the ssb meter, swr meter, about. This instrument can be used and calibrated from 1 khz and up to 500 mhz it is possible to measure power relative all the way up to 900mhz a software routine can calibrate the 0dbm point at 5 different frequencies to make this instrument accurate within 0. Mar 16, 2018 the circuit is based on two ad8307 log amplifiers, which are connected to the forward and reflected ports on a directional coupler the ad8307 amplifiers gives a dc voltage of about 25mvdb of the input signal, which is amplified using an opamp lm324. If i apply a square wave with 0dbm, what will be the sine wave power read by the ad8307. Ad8307 module for rf power meter rssi for arduino or other mcu or standalone a. Make sure the input on the ad8307 never exceeds 10mw 10dbm better.
This article describes a simple to build, yet potentially accurate digital power meter. I originally set up this board to work with the circuitry in qex article may june 20 by loftur jonasson tf33ljve2ljx, squeeze every last drop out of the ad8307 log amp pp. A very simple to build, menu driven rf power meter, based on. Usb 0500mhz rf power meter with ad8307 using pic microcontoller. Arduino code for 0500mhz, 1nw to 100w rf power meter. Swr power meter with protection for solid state pa page. Because the ad8307 is frequency compensated following an article here it can be used as a mw meter in the range up to 500 mhz. Nov 24, 2017 on this video i will show you how to use smd ad8307 on breadboard and use ic output to calculate signal power strength by analog vu meter. For programming changes to the nextion module, the arduino nextion library will need to be added to your library folder under your working arduino folder set. The ad8307 output is connected to an arduino analog input and computation is done in software, with output to the lcd and usb line. To do this, all the meter needs is two accurate signal levels, 30 40 db apart, as calibration points. He used a pic to convert the dbm readings back into watts and to calibrate the device, too.
Usb rf power meter is based on popular ad8307 watt meter ic and pic18f2550 microcontroller. There is no filtering on the power detector so it can measure from very low frequencies to 500mhz. Ad8307 rf decibel power meter circuit electroschematics. Oct 16, 2015 the best way to test these would be to build a simple power meter.
Rf power meter with arduino, ad8307 and oled by rudi imbrechts. I used the arduino software from the book, and modified it to include a larger display and some other things. Listed under the technical reference arduino category that is about ham radio arduino projects. Unfortunately, accurate, wideband models are fairly expensive. About swr wattmeter with arduino uno shield the resource is currently listed in in 2 categories. Whether we are tuning up homebrew equipment, checking antenna vswr, adjusting a linear amplifier, or just monitoring output power during a contest, almost all aspects of ham operation can use a power meter. Psm300040005000 rf and microwave power sensor power meter.
This was my first smt design, and i am fairly happy with the result. About arduino power and swr meter the resource is currently listed in in a single category. Make an arduinobased power and swr meter for amateur radio the arduino platform lends itself nicely to other pursuits, and one of these is amateur radio. To measure output rf power of transmitter connect ad8307 probe input directly to the output of your transmitter antenna output. Some people who built the power meter came with some good ideas and. I have a cts crystal oscillator 50mhz mxo45hs50m000 dip8, ive read that this crystal allows me to make a signal generator of 10dbm to calibrate the ad8307 with 50 mv.
Arduino code for 0500mhz, 1nw to 100w rf power meter mike. A very simple to build, menu driven rf power meter, based. Swr power meter with protection for solid state pa the pa3csg. The best way to test these would be to build a simple power meter. With a log amp the output voltage is a straight linear representation of wattage. Removing the dummy load portion of that board i was able to import the ad8307 power meter circuitry with only a little change in the original layout. I wanted a board that could be mounted in a remote enclosure or could be put in a self contained box with the rest. As you may notice, there are no buttons on the device. Swr power meter with protection for solid state pa the. This link is listed in our web site directory since wednesday aug 3 2016, and till today arduino power and swr meter has been followed for a total of 3004 times. C1 and this rf wattmeter uses an ad8307 to measure the power level. Last weekend i started building a rf power detector with an ad 8307 log amp. Instead of using lcd display module the meter connects to a pc via usb port and displays measurements on a computer via usb rf power meter software.
So the challenge was to try some ugly construction using a piece of copperclad. I started it from scratch and decided to build an accurate power meter for the directional coupler described here. After finishing with a simple vswr plotter using an arduino pro mini and a tft, i decided to improve the rf measurement section of the analyser with an ad8307 based power rf meter. The software settings can be changed to use 1050dbm attenuator and thus allowing to measure rf power higher than 2w. I should note that this prototype uses a true nano, it contains a. Is there a way to convert a square wave to a sine wave with. That would be 20dbspl to 100dbspl, hardly likely youll need that much. Swr wattmeter with arduino uno shield resource detail. Code is based on sketch of mike richards g4wnc and adapted for. The dds is an ad9851 running at 150 mhz and the logarithmic detector is a ad8307.
I used the arduino software from the book, and modified it to include a larger. Although i bought the book and respect the of the authors i will share my own schematic here. The ad8307 amplifiers gives a dc voltage of about 25mvdb of the input signal, which is amplified using an opamp lm324. The slug repellent tape is excellent for rf blindage, only needs to have something bellow to give some more rigidity. The hardware was kept easy, as the calibration interceptpoint, voltage per db shall be done in the software. What is it an rf power meter is a device which you can use to. Pwr10rmsrc, 1mhz10ghz, usb power sensor, ad8319, succobox, arduino micro. This swr power meter was my first own project for the arduino. It measures, in one range, power from 100 nw to 100w 9 orders of magnitude covering all hf bands up to 2 metres.
I had the layout for the power meter part of the specam and the arduino and display that i had done for the dummy load wattmeter. What is it an rf power meter is a device which you can use to measure the power a transmitter outputs. New ad8307 power meter the speaky hf ssb transceiver. Using ad8307 log amplifier for sound level meter arduino. Ad8307 module for rf power meter rssi for arduino or other. Keep this in mind as you set the full scale voltage of your transducer. A word of warning when copying this code the arduino software doesnt like the marks when they are copied, you need to replace all of them by physically typing the into the program. Is there way to calculate the sine wave power equivalent to a 0dbm square wave. An diy rf decibel or power meter is an indispensable instrument in any radio workshop. I build the same display layout as from the oz2cpu meter because i liked that. I wanted a board that could be mounted in a remote. Mar 19, 2020 you will find the schematic of the directional coupler, the schematic of the ad8307 amp circuit, the excel file i used for calibration, a diagram of the smoothing algorithm, a fritzing wiring.
Ad8307 rf power meter probe is used to measure the strength of rf power and may be mounted in a small metal enclosure. This article looks at combining the ad8307 module with a display option based on an arduino nano. Its a ad8307 rf wattmeter from oz2cpu in a pcb that can be placed on a hammond 1590b box. In the future it will probably be an full scale swr monitor.
Autocap integration integrating the meter into autocap was straightforward, and the software now offers to use any working sensor based on this kit. Digital wattmeter with ad8307, pic16f876, lcd display. A milliwatt to kilowatt rf power meter using the analog devices ad8307 a friend of mine, dick benson, w1qg, built a pretty cool combined forward and reflected power and swr meter using two ad8307 logarithmic amplifier chips from analog devices. The desig is simple and is popular among hobbyists. Output is displayed in dbm, watts nw, uw, mw and w range as well as input voltage. Rf power meter with ad8307 circuit wiring diagrams. Ad8307 power meter the speaky hf ssb transceiver and. Im a member of the model aircraft c19lub fms spaarnwoude near amsterdam and i started building and flying drones.
An experimental rf power meter using arduino youtube. A lot of people have done the open source power meter with arduino. I was looking for pic mcus and found that pic16f876 is going to nrnd, so after this i found it was the best time to start this project. The ad8307 puts out a voltage that is proportional to the log of the input power. The rf power in dbm can be read directly with a multimeter, and ive found it particularly useful for measuring rf filter response when combined with a sweep generator and an oscilloscope. If you build the meter using the same voltage reference and component values in front of the ad8307 as indicated in the diagram above, then i would expect reasonable accuracy with the parameters used by default in the firmware. Calculating swr with rf directional couplers arduino.
Oct 25, 2015 after finishing with a simple vswr plotter using an arduino pro mini and a tft, i decided to improve the rf measurement section of the analyser with an ad8307 based power rf meter. I always wanted to build a rf wattmeter with the ad8307 and oz2cpu design. This meter had to be suitable for a large power range. You will find the schematic of the directional coupler, the schematic of the ad8307 amp circuit, the excel file i used for calibration, a diagram of the smoothing algorithm, a fritzing wiring. First of all, this swr meter in this article is not exactly homebrew, as i based the circuit on the schematic in the excellent book arduino projects of amateur radio. A preprogrammed microcontroller type pic16f876 with builtin 10bit analogue to digital. Transfer the code from funduino uno board to a arduino mini board. Ad8307 rf logarithmic power meter, keenso ad8307 rf power meter logarithmic testing detector 0. Its a mix from the datasheet and from the circuit in emrfd experimental methods for rf design, the ad8307 part of the diagram is from datasheet and the opamp parts is from emrfd placed an 68k resistor in series with my 100ua meter in the original. The better rf swr meters available these days can give very good performance using log amp detectors, with many popular designs based on the analog devices ad8307, good for a claimed 92 db range and 0500mhz bandwidth. Copy and paste the code below into your arduino ide.
In the software you can enable the alarm function and the limits for the alarm settings. It is designed to operate as an inline power meter and displays the results on a 16 digit lcd display. Rf power meter with 1mhz10ghz bandwidth and 55db dynamic. Oct 22, 2015 an rf power meter is a device which you can use to measure the power a transmitter outputs. The ad8307 voltage output connects to the arduino a0 pin. Ad8307 power meter qq article additional build notes. Test the code in an simulated environment by simulating the input voltage with an potmeter. Why did i built it im a member of the model aircraft c19lub fms spaarnwoude near amsterdam and i started building and flying drones. Rf power meter with arduino, ad8307 and oled by rudi imbrechts on7ir january 2019. It consists of from left to right the 5v power supply, the arduino nano, the ad8317. The circuit diagram of the decibel meter in figure 1 stands out by its simplicity, which is due to the type ad8307 monolithic demodulating logarithmic amplifier, ic1, from analog devices. A simple digital power meter warrington amateur radio club.
Jun 24, 2015 output is displayed in dbm, watts nw, uw, mw and w range as well as input voltage. Code is based on sketch of mike richards g4wnc and adapted for use with an i2c oled display, some display functions added. Even the menu functions i build in the new software. This instrument can be used and calibrated from 1 khz and up to 500 mhz it is possible to measure power relative all the way up to 900mhz a software routine can calibrate the 0dbm point at 5 different frequencies to. It is not just wattmeter, it is a 3 channel power switch with meter function per each channel.
The driving part of the program is the adcinterrupt routine. I currently own an octocopter with 1 m span and added a camera with gimbal and a live video link to it. A meter that reads 5v at 100w power will have a resolution of about 100mw. Here is yet another ad8307 based rf power meter which adds an opamp to produce a dc output voltage of 1mvdbm e. It is based on a pic 16f876a and an ad8307 logarithmic detector. So with a 92db dynamic range, lets say you use 90db of that for simplicitys sake. Portable rf sniffer and power meter paul wade w1ghz 2003, 2004 rf power meters are extremely useful instruments. The measurand quantity to be measured is applied to pin 8 inp of ic1 via input socket k1 and capacitor c1. Make an arduino based power and swr meter for amateur radio the arduino platform lends itself nicely to other pursuits, and one of these is amateur radio.
Is there a way to convert a square wave to a sine wave with the same power. Make an arduinobased power and swr meter for amateur radio. Mar 21, 2015 usb rf power meter is based on popular ad8307 watt meter ic and pic18f2550 microcontroller. Dec 05, 2015 homebrew swr and power meter first of all, this swr meter in this article is not exactly homebrew, as i based the circuit on the schematic in the excellent book arduino projects of amateur radio.
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