Photo with ATMega 328P and SI5351 frame Project to visualize the various functions of a transceiver on a graphic display: in the specific case for the 40 m band. Furthermore, the frame with the SI5351 is present and therefore the VFO is created. As can be seen from the photograph, in addition to the frequencies set on two VFOs (VFO-A and VFO-B), the mode (CW or LSB), the AGC (ON-OFF), the split (ON-OFF) and the S-Meter bar. The frequency is varied via encoder and to speed up the operation via two buttons that allow you to increase or decrease the frequency with a step of 100 Hz or 100 KHz based on the position of the cursor. The other buttons are used to select the functions listed above. The obviously temporary connection with the yellow crocodile in the photo serves to inhibit the buttons and encoder when switching to transmission. A few words about the SI5351 Adafruit module: it provides three freely programmable output frequencies in the range from 8 KHz to 160 MHz so it is programmed to provide the signal for VFO - A on clock 0, clock 1 for VFO - B and clock 2 VFO - B minus the F.I. value: uses the I2C protocol to communicate with the ATMega328P (Arduino). If anyone is interested in the implementation I can provide the source and compiled files of course it will be necessary, if used on other bands, to modify the values .