About 50 years ago, I built an AM radio using a crystal. For a kid in the 60s, this was very cool. OK, that's a lie. It was very nerdy, but it was cool to me.

Background

More than 10 years ago I bought a Sony Radio Alarm Clock. For the time, it was an excellent device.

After years of abuse, tuning to an FM station became problematic. In 2017, the buttons stopped working. I could have fixed these, but I thought it would be more fun to replace the guts with a raspberry pi. However, the final build is larger than the original case. So, I tossed the case.

Of course, all of the functions of a Radio Alarm Clock can be accomplished with a SmartPhone.

There is no point in building a Radio Alarm Clock. A home built alarm clock radio costs way more than buying one and it took a crazy amount of time to build. But this project made me feel like a kid again and I learned a lot.

Features

The alarm clock radio has the following features:

• • Set an alarm

  • Play FM over-the-air radio

    • Store a list of favorite stations

  • Play Internet radio

  • Play songs from my library

  • Use a touch screen interface rather than the buttons

    • Select an FM Radio station

    • Select an FM or internet station

    • Select a mode (FM, Internet, Songs)

    • Set or clear an alarm

    • Change the volume

  • As an added bonus, the Raspberry Pi USB ports are used to charge my kindle and iPhone

Music Players

There are several excellent music players running on the Raspberry Pi including: Mopidy, Volumio, Moode, RuneAudio and Pi MusicBox. In sticking with my focus, Mopidy and Peppy are the only ones running on python. I have an old speaker and I am not an audiophile. So, I am not worried about the best audio performance. I am not sure which audio player is best. I spent a while investigating each of these solutions, but eventually gave up thinking it would be easier to just build my own. Of course, I was wrong.

Parts

• • Raspberry Pi 3 B+

  • AdaFruit 2.8 inch capacitive resistance PiTFT display

  • female-female jumper cables

  • male-female jumper cables

  • FM Receiver Si4703 Board

  • Earbuds (temporary)

  • Icstation's LM386 Mini Mono Audio Amplifier Power Amp Module 5V-12V for over-the-air FM Receiver

  • For the speakers, I used cabbaged parts from some unknown device. If you don't have a speaker this is recommended by the the Peppy build:

    • Sony 20W 4 Ohm Full Range Speaker - XS-GTF1027

  • 3.5mm male-to-male audio cable

  • 12V barrel plug power supply for the HiFiBerry AMP2 and the rest of the project

  • HiFiBerry Amp2 amplifier for internet radio and songs

  • USB cords for iPhone and Kindle charging

Tools (all reusable)

Soldering Iron Station, jig saw, drill, monitor with HDMI input, USB wireless keyboard and mouse, voltmeter, prototype board,

CAUTION: Speakers have very large magnets and some small magnets. Both are capable of erasing a microSD Card, destroying a raspberry pi and the FM Receiver. Keep the components far away from the magnets I was almost done with this project when I accidentally allowed the microSD Card to touch a magnet, and I had to toss the SD card.

Step 1. Setup Raspberry Pi

Step 2. Add HiFiBerry AMP2

Step 3. Create over-the-air FM Radio Receiver

Note: The 3.5mm male-to-male audio cable acts as the antenna for the FM Receiver

Step 4. Add 2.8 inch capacitive resistance PiTFT display

Step 5. Wiring

There are a lot of connecting wires in this project. Step 3 adds a perf board, which simplifies the wiring and reduces 5v noise in the FM audio.

On the perf board, each of the headers in a block are soldered together. The transistor and capacitor provide a simple filter for the 5v input from the Raspberry Pi.

The other steps should contain all the wiring diagrams required. Let me know if anything is missing and I will add.

The HiFiBerry, PiTFT and FM Receiver all use I2C. I read a lot I2C and thought this was going to take me a while to figure out. When I hooked everything up with no resistors, it just worked. and I am not sure why.

Step 6. Download acr.py

The python3 crontab module is required for the alarm clock. Install using:

$ pip3 install python-crontab

Download acr.py

$ wget https://raw.githubusercontent.com/dumbo25/tkinter-alarm-clock-radio-gui/master/acr.py

Step 7. Start on boot

NOTE: This step worked for a while. Now, I get an unhandled errno 121. Something to do with I2C. I removed the line from autostart. I need to use a USB mouse and keyboard to start the script (python3 radio/acr.py). Arrgh

I want acr.py to start on boot

$ chmod +x acr.py

Add acr.py to autostart

$ nano /home/pi/.config/lxsession/LXDE-pi/autostart

and add the line at the end:

@python3 /home/pi/radio/acr.py

It takes a few minutes for the acr.py to start, be patient

Step 8. Put it all in a case

I attached each of the board to a sheet of plexiglass to keep them in place.

The case is up to you, because the size and shape depend on the size and number of speakers. I built mine out of plywood and then painted it glossy black.

When I put the alarm clock radio on my night stand, I wondered if I could add an iPhone and Kindle cords to the Raspberry Pi's USB ports. I tried the iPhone and it started charging. I do not know yet if there are side-effects from doing this, or what the charge time is, but it seems to work.

Appendix

I built the Alarm Clock Radio in steps. Some of the steps are shown above, but some are not. The unshown steps were not required. For example, when I was done, I combined several individual scripts into acr.py. Some of the steps below are creating a GUI, adding internet radio and songs.

• Music Basics

• Alarm Clock

• Internet Radio Player

• Song Player

• tkinter GUI

• FM Radio Receiver

• Add audio amplifier to FM Radio Receiver