Skip to main content

Create Network Transceiver - DVPi Audio In/Out adjustment

Create Network Transceiver - DVPi Audio In/Out adjustment

I will make a video for this post and post it on YouTube. (Next monday)

Describes the settings for DVPi audio input/output. If you are familiar with Linux, you probably already know. In particular, if you are transmitting too loud or too small when you are TX Mode, be sure to read this article.

This is very important for using DVPi well, Let me explain how I set it up.

1.Connection of sound-related devices
DVPi uses a USB sound card. Below is the USB sound card I use. 
You may use an external speaker. If you have a spare computer speaker, you can use it as is. Just connect the external speakers to the sound card's headphone connector.

However, I decided to connect the small amplifier and the speaker directly to embed it in the case.

Audio Out and In are connected as shown below. GND is common, so only one is connected.

I have used an amplifier like the LM386 so far. I was looking for an easy way to make it and found the product below. As a 5Volt amplifier for less than $1, I was quite satisfied.

I bought PAM8403, but you can use what you can easily buy around you.

It is equipped with a variable resistor, making it easier to use.

I decided to use only one channel. That's enough.

2.DVPi Audio In/Out Tuning (It is important)
 To use DVPi well, please set it up once.
 If your Raspberry pi or sound card is replaced, you will need to set it up again.
 2.1 Execute putty.exe
  putty.exe can be downloaded from the Internet.

You can find the IP assigned to DVPi  by dhcp in DVPi's Config window. 
Enter the IP address of your DVPi and click the Open button.

Perhaps the first time you connect to your DVPi with Putty, you will get the following warning. Ignore and click Yes.

 2.2 Login SSH (putty.exe)
  Login as (ID): pi
 Password    : dvpi

If login is successful, the screen below appears.

 2.3 Execute alsamixer and Select 'USB Sound Card'
Type alsamixer and Press the 'Enter' Key

The screen below will appear.
Press F6 on your keyboard.

The sound card selection window appears as shown below.

Press the arrow keys (Down) on the keyboard to select'USB Audio Device'.

 2.4 Adjust 'Speaker' and 'Capture' 
Then, the screen to set the volume of'USB Sound Card' appears as shown below.
When the speaker is selected, press the up or down arrow keys on the keyboard to change the speaker volume.

I recommend setting the speaker volume to 90% or higher.  You can adjust the actual volume through the variable resistance of the amplifier.

Press'F5' to adjust the volume of the microphone connected to the DVPi.
Press'F5' on the keyboard.

The'Capture' item is also displayed as shown below.

Press the right button of the arrow keys on the keyboard to move to CAPTURE.

Press the up and down arrow keys to select the volume that is right for you.
(Caution: You do not need to adjust the MIC displayed in the middle)

When all adjustments are done, press the'ESC' button to exit.

On the Internet, it is recommended to run the 'sudo alsactl store' command after adjusting the volume.

Enter'sudo alsactl store' and press enter Key.

I set the audio out to 100% (Speaker : 100) and then adjust the volume using the variable resistor connected to the amplifier. This works pretty good.

I first set the MIC (Capture) volume to medium, and then I attached a variable resistance to the MIC.  The volume of the microphone was also adjusted through a variable resistor, but noise was generated in my case.
It is recommended that the microphone be adjusted as described above, preferably without variable resistance.

thank you for reading.
KD8CEC, Ian 


  1. Here is my own version of standalone DVPi ...
    - Raspberry Pi Model B v. 1.2
    - Official Touch Screen 7 "
    - External SSD 120GB
    - Condenser microphone SF-666
    - Headphones then 3W amplifier and speaker.
    - RVPi V. 0.5
    - DVSwitch menu F1PTL
    - Adjustment of the various variables for proper operation

    1. Wow! It's Builtin DVSwitch. Perfect.

      I am adding some features to Version 0.7,
      Because it cannot be distributed frequently due to the file size, this time I am going to put all the features for Version 1.0
      Maybe Version 0.7 will be a beta version. Then please test.


  2. Thanks for your great job, Ian!
    So I used the official Raspberry LCD touchscreen (7 "). The DVPi's screen is superimposed on the Linux desktop and covers 2/3 of the surface. It worked immediately (I was simply forced to reverse it by 180 ° with a command lcd_rotate = 2 in the config.txt file).
    On the other hand, I tested the HDMI button with a suitable screen: the Raspberry reboot, the LCD screen works normally (although inverted by 180 °) and the HDMI screen connected to the rear socket of the Raspberry only displays the multicolored test pattern. Same thing with the other buttons related to the display (3.5 LCD and 3.5 LCD 180). For information, I boot my test Raspberry from a 120 GB SSD (it's a luxury ;-)).
    - Do you think that it is possible to boot DVPi in priority on the HDMI screen and if so how?
    - In addition, would it be possible to have the entire surface of the Linux desktop take up the DVPI screen?

    73 from F6CYK/Tony (France)

    1. Tony
      I've never used a official RPI 7" LCD, but it seems to use an LVDS port.
      Because it works with a different driver, it cannot be controlled with the DVPi's buttons. DVPi does not seem to be applied to LVDS driver as it calls commands included in LCD driver connected to GPIO.

      I originally made the DVPi based on 3.5", but I also have plans to release a version that supports several resolutions after Version 1.0.

      Ian KD8CEC

    2. Can't wait for support for the dedicated 7 in screen for Pi. Love the project, planning on building one Trans for the car. 73 de W9GIL aka SQ6WG

  3. will this work with a nextion screen??

    1. Unfortunately, Nextion LCD is not supported.
      Ian KD8CEC

  4. Hello Ian,
    I have the project up and running. It's great. I had an old 3.5" LCD screen and is perfect. I have an MPOW usb headset/mic and plugged it into the usb port ... worked perfectly. Now ready to start packaging. Rotary encoder and enclosure ordered.

    Question: I have been using DVSwitch with Android devices for 18 months now and really like it. The audio is improved by using an AMBEServer of some sort. I plug in a ThumbDV and make appropriate changes to Analog_Bridge.ini. Do you suggest using an AMBEServer of some sort? FWIW, I find the DSP makes a huge improvement to received audio.

    tnx ... Tom VE3NY

    1. As mentioned in other posts, please experiment and share some more improvements.
      I am going to experiment to see if one AMBEServer can be used for multiple DVSwitches.
      Ian KD8CEC


Post a Comment

Popular posts from this blog

Release CEC Firmware v1.200 for uBITX All version(include V2, V3, V4, V5)

Release CEC Firmware v1.200 for uBITX All Version (include v2, v3, v4, v5) I did the firmware work for v5 when uBITX V5 was released, but I release it now. I received the feedback from a thankful beta tester and tested it myself by converting my uBITX v3 to v5 but I was not sure. I ordered the uBITX V5 and delivered the correct uBITX V5, so I made a little more fine-tuning. If you use V2, V3, V4, you do not need to update this firmware.

Release EU1KY AA Firmware CEC Version 1.01 and 1.0a

Release EU1KY AA Firmware CEC Version 1.01 and 1.0a It is the stabilized final version of EU1KY AA. Updates starting with Version 0.1 continue to add features. Please refer to the link below for added features. I have separated the Version to 1.01 and 1.0A for users who want to use AA only for instrumentation purposes. *  If you want to use all the features added up to Version 0.71, please use Version 1.0A. *  If you want to use it only for instrument use, please use Version 1.01 Version V1.0A Version V1.01 1.Download Firmware Version 1.01 and 1.0a Version 1.01 (Version with only antenna analyzer function) Version 1.0A (Version with all features added up to Version 0.71) ConvertRXP (Converters for using AA measurement data in other tool

uBITX with Nextion LCD (CEC Firmware) - Installation and Introduction

uBITX with Nextion LCD (CEC Firmware) -  Installation and Introduction uBITX CEC Firmware supports various LCD since Version 1.08 (16x02 Parallel, 20x04 Parallel, 16x02  I2C, 20x04 I2C, 16x02 Dual LCD with I2C). Supports Nextion LCD (Graphic LCD) from Version 1.09, Version 1.09x is primarily aimed at Nextion LCD support. Also 1.09x will continue to be Beta version. If you want a stable version, please use 1.08 or 1.1 version to be released in the future.