All the below Arduino files download as a text file, to then copy and paste into the Arduno IDE. Due the nature of some of the Arduino programs, Radio Hams and shortwave listeners will need to down the drivers of the touch screen and si5351 dds as well as the ADS1115 ADC board for the appropriate application. However it is suggested to download the Arduino code from here rather than from my google drive page. For further info, click on the tab button below for my blog “Radio Ham Technology”. Unless stated, the code runs on an Arduino Uno device.
Please do read the comments at the start of the each text code listing, the text code then copied and pasted into the Arduino IDE program text window.
The choice of alternative raduino for the bitx40 has been provided as I have found that my own raduino that came with the bitx40 started to develop a fault. While the occurance is perhaps not the fault of the supplied offering, I found that the raduino listing of github was not so complete, so I have managed to cobble together a version of the raduino with a few of my own thoughts, and produced a version that is more help for my own uses. Users of the bitx40 are welcome to use the code for their own bitx40 projects, and as many hams have retuned their bitx designs for other bands, please feel free to change the operating frequency of choice. The 60m band has been one choice I have noticed for hams to make.
Attached to this page is a new arduino signal generator program. The list “si5351 dds tri sig gen and keyboard shield” uses the arduino Uno and its keyboard shield and the si5351a dds board, all found from ebay or amazon. The tri sig gen code enables each of the si5351 dds oscillators to be programmed separately and its frequency altered as any vfo using buttons. The inc/dec values of each oscillator are each separate, and on each vfo has its own last used frequency memory with the inc/dec steps also memorized. Ideas for this project is for a single or twin or a tri vfo single source for RF measurements, such measurements are perhaps intermodulation calculations for both RX and TX tests. May perhaps also RX signal I.F. bandwidth measurements and also perhaps AF filtering tests using an RF signal source at the antenna input of the radio.
Just a note regarding the alternative Raduino code for the bitx40, I noticed an error in the posted coding, sorry about that, so have now posted a bar graph “signal meter” version. The signal meter as a bar graph display shows on the lower half of the two line display. Please read comment notes of the new coding for correct use.
Regarding the antenna analyser software, please note that the “v_forward” variable is the antenna loading voltage at the antenna connection, while the “v_reflector” is the source voltage from the radio terminal connection to the coax cable. Using a constant current theory, and freezing in time the circuit, if the antenna loading voltage is 10volts, and the radio terminal voltage is 5 volts, then the SWR ratio is (antenna loading volts / radio terminal volts ) = 2:1 thus the antenna load is ( 10 / 5 ) * 50 = 100 ohms. If the SWR match was 1:2, then the antenna loading is 25 ohms.
Should the antenna laoding be a 50ohm dummy load, then the antenna load voltage would be the dummy load, then the radio terminal voltage would be the radio terminal impedance. If the dummy load is 5 volts, and the radio is 2.5 volts, then the radio output impedance is less than 50 ohms, or the radio terminal voltage would be 5volts. Therefore, the radio output impedance is less than 50ohms, and in this example, the radio would be 25ohms output impedance, and thus would require a inductive inductance bridge match to bring the radio up to 50ohms. If you cannot get an antenna match, test the radio’s transmitter terminal impedance by using this method.