Roehre1 (HMV 682)
- HMV 682
- Philips 836A
This is a nice internet radio I built. It can tune into internet radio stations from all over the world. It's built into the case of an old valve radio and the controls work pretty much the same way they did in radios back then.
Vintage valve radio
I bought an old radio off eBay. It's from the 30s and was manufactured in the UK by "His Master's Voice"
I removed the old electronics and speaker, and left only the wooden case.
The core of the radio is an old 12" laptop. I removed the LCD panel from the casing and fitted it with the laptop in a wooden frame. The 12" panel is a bit too large for the 8" window, but it still fits in the radio case. The UI of the software only uses the visible part of the screen.
The radio is controlled by several controls which are connected to an ATMega328 micro controller.
The built-in sound card of the laptop was bad quality, so I decided to buy a USB sound card from Creative. It's the white box below the USB hub
I bought a cheap amplifier and two equally cheap speakers from eBay. They were originally meant for cars.
The photo shows the frame with the electronics (left side) after it was inserted into the radio. The amplifier and the speakers are on the right side.
The laptop usually doesn't use its fan at all. But on a hot day, or if a lot of cooking is going on in the kitchen, it might start. Since it is quite broken it produces a very loud and nasty noise. I added large fan in front of the laptop and automatically switch it on when the CPU gets hot. This keeps the radio silent.
Issues like this are reasons why I don't think that using a laptop is a great idea for such a project. But I couldn't find a affordable 8" screen for a Raspberry Pi, while I had an old laptop laying around.
There are currently to PSUs in the radio, connected to a simple extension chord:
Laptop, amplifier and fan are connected to relays that are controlled by the micro controller. Fan and amplifier are powered on and off when needed: Fan turns on when the temperature of the CPU gets too hot, while the amplifier gets activated when music is playing. The amp will get turned off some time after the music has stopped.
For the laptop, micro controller and software on the laptop work together:
I measured the power consumption:
The laptop runs Debian and a the Music Player Daemon (MPD). The UI is written in C and SDL. The UI gets the information about the controls from the micro controller by USB.
The program on the micro controller reads out the information from the controls and sends an update via USB to the laptop if something has changed. It uses the v-usb library to handle the USB connection, so no additional chip is needed for USB.