|Raspberry Pi 3 and filter boad (shield) from TAPR|
I still don't know much (if anything yet) about those languages but I received my Pi 3 in the mail from Amazon three days ago and a $20 WSPR shield from TAPR an hour ago and am already on the air with 100 mW on 20m WSPR and have been spotted all over the US and Canada after less than an hour's worth of transmissions in my early afternoon.
I fully expect to be heard in Europe this evening, and all with a cheap, tiny set-up that that is completely independent of my shack computer. Based on the reports the Pi appears rock stable in frequency.
My set-up procedure differed slightly from that described in the article. For those similarly interested and who may know little to nothing about these amazing devices, here is a description of how to "whisper raspberries".
|100mW out confirmed|
What you Need
You probably already have half of these items. The first three can be bundled together in your Amazon order:
Raspberry Pi 3 Model B
5V power supply
32GB SDHC memory card
Shield for WSPR from TAPR (this is both an amplifier and a low-pass filter)
USB keyboard, USB mouse, HDMI monitor
A PC with Windows to write R-Pi image to SD card
The QRP Quarterly article directs you to install the shield onto the Pi, boot it up, download the WSPR program and start transmitting. I recommend against this and suggest instead that you get the R-Pi up and running on its own first without attaching the WSPR shield yet.
You'll need to download three free programs to your PC:
Ubuntu Mate for Raspberry Pi 2 and 3
7-zip (similar to WinZip)
Rufus utility (this allows you to write an image file (Ubuntu Mate) to the SD card
Install 7-zip and Rufus onto your PC. This is also a good time to create a (free) account on GitHub. You'll need that later in order to download the WSPR program onto your Pi.
Use 7-zip to unzip Ubuntu Mate. It'll unzip to an 8GB file. Then use Rufus to install the unzipped Unbuntu file onto your SD card. Once you open Rufus to do this, make sure that your SD card is selected for "Device". This is very important since whatever is selected in this field is about to get erased and written over!
For "File System" select Large FAT32.
The following three boxes should be checked:
- Quick format
- Create a bootable disc using 'DD Image'
- Create extended label and icon files
Hit 'Start' and go have a snack.
And now to the Raspberry...
Once the image file has been written, remove the SD card from your PC and insert it into your Pi. Connect the USB mouse and keyboard to the Pi, along with an HD monitor.
Now apply power to the Pi and it will begin booting up. At the end of the boot-up you will be presented with a Welcome screen. Click the large Raspberry Pi Information button on the Welcome screen, click the Resize button and then restart the Raspberry Pi. This ensures that all of your 32GB are available.
The next task is to set the system time and configure the Pi to communicate with your router. The Pi 3 has built-in wireless capability (and Bluetooth). Icons for time and router config are in the upper right-hand part of your monitor. Once this has been done, go to System (top left of monitor), Administration, Time and Date and then set the Configuration field to 'Keep synchronized...'
At this point, you have a fully functional Raspberry Pi with a word processor, spreadsheet, web browser and other programs built in.
Now that your Pi has online access, it's time to download the WSPR program.
To download and install it, hit CTRL-ALT-T on your keyboard to open a terminal window and then enter the following:
sudo apt-get update
sudo apt-get dist-upgrade
sudo apt-get install git
git clone https://github.com/JamesP6000/WsprryPi.git
You will have to enter your password for the Pi and your user name and password for your GitHub account.
Time to get on the air!
Shut down the Pi and remove the power connector.
Attach a 20m antenna to the TAPR WSPR shield. Labeling on the circuiboard indicates which terminal is for the ground braid and which for the center lead. I just cut an RG-58 BNC cable and attached the cut end to the board and the connector end to the feedline from my Yagi.
Now seat the TAPR shield onto the Pi and push it down firmly.
Power up the Pi, open a terminal window (CTRL-ALT-T) and type:
sudo ./wspr -r -o -s callsign gridsquare 20 20m
Use 6 digits for your gridsquare.
Enter your password if asked. WSPR transmissions will begin on the next even minute.
|Screenshot of WSPR program running in Pi terminal window|
If all is successful you should see your callsign spotted after several minutes on WSPRnet (make sure to select '20m' in the field just under the map).