Talking Alarm Clock
I've been playing around with the Voice Recorder IC's that were used on the Staples Easy Button Mod. The uses seem endless, however one thing comes to mind.
From my childhood one of the toys that I remember really wasn't a toy - but a clock. Yes, there was a talking "Masters of the Universe" alarm clock that had this really obnoxious dialogue, which went something like:
"He Man, Its Teela
we've been called again
we must not let Skeletor keep us from our friends."
"Then call with me Teela:
Its time to wake up
smile and be happy
brush your teeth and make it snappy
we never fail with our wake up verse because we're the Masters of the Universe."
Taking this track and retrofitting an ordinary digital alarm clock would be great! As an added challenge, the retrofit must be done in such a way that only the beeping sound is replaced (you can't always wake up to Teela).
After a search on E-Bay, I was able to buy a clock that was broken (no audio and alarm switch stuck on) for $15.
After some prying at the clock face, I was able to get to the audio player. This is definitely a time warp, as the only electrical component is the motor used to spin a miniature record.
Notice the needle is attached to the base of the translucent speaker cone. It's a mini-phonograph!
In the case of this clock, a rubber belt had slipped off of the motor spindle and after this was reset, the clock could speak again! Here is a recording of the clock, which was filtered via Audacity to remove some of the record crackle and pop.
With the audio track finally obtained, the next phase is to get an appropriate alarm clock to upgrade.
With this end in mind, I went to the local Target to get a "Cool looking" alarm clock. The RCA model I chose had a simple display and a digital radio. After bringing it home and popping it open I was horrified to see how this thing was put together. There were multiple PCB's all connected with a tangle of hand soldered wires. In addition, the lack of space had them leaving long legs on the electrolytics and then hot gluing them to the top of previously inserted components. This has to be one of the worst designs for manufacturing. I can't believe it even worked!
The New and Improved Talking Alarm Clock
After failing to find the perfect new clock, I turned to an old alarm clock that was laying around. One of the drawbacks with choosing a clock that is a few years old is finding datasheets for the parts it uses. It seems the two IC's used in my Sony alarm clock (Radio Tuner Sony CXA1019 and the Clock Sanyo LM8560) were discontinued. After some searching, a Japanese version of the radio IC datasheet was found.
After tracking down the alarm outputs from the Sanyo IC, the basic principal for the clock was mapped out. There are 2 alarm outputs: The first is the output set when the alarm time is reached - with the option of listening to a beeping sound or the radio. The second is the sleep timer, and is usually set to leave the radio on for up to an hour. Our focus is on the alarm output, as one of the premises of this project was to keep the alarm clock as functional as possible.
The operation of the radio and beeper is a little tricky. The beeper is always present, however the duty cycle is such that with a relatively small capacitor, a general purpose NPN can be biased to enable the Sony radio IC's gain control. Looking at the alarm output on the, the LM8560 functions approximately the same was as the Sanyo LC85632, which has a much better data sheet (shown below).
The fact that the radio is always enabled explains why you can sometimes hear a little bit of the radio playing on some alarm clocks even when only the beeper was selected. A separate line into the radio IC (which I will assume is a line in since I can't read Japanese) also delivers the beeping signal but with a chip resistor for the volume control. This signal was measured at 40mV Pk-Pk so the retrofit will attempt to duplicate these levels. It is interesting to note that the clock uses the 60Hz AC signal to keep time. When the battery backup is engaged, an external oscillator is used (and why the clock will be a few minutes off after running on battery power for a while).
Now that the basic operation of the clock is understood, a location to tap into the circuit is needed. Power, ground, line input, and a switch output are needed. This part proved most tedious, as the lack of documentation hurt. Starting at the alarm selector switch, the output line was traced to where the beeper went into the line in on the Radio IC. By copying the same circuit for switching based on the duty cycle of the alarm, the enable for the sound track was obtained. Finally, the power and ground pins for the Sony Radio IC were tapped. Unfortunately, the DC regulation on the board is pretty simple and seems to vary quite a bit. In addition, the IC's that Sony used can withstand voltages > 7VDC, while the Winbond chip tops out around 5.5VDC. Consequently, a 3.3VDC regulator was chosen to keep the voice module functioning. A 4 pin connector was used to tie the alarm clock into the voice module.
A PCB was created with the help of a friend (Thanks Monte!) that captured the requirements above along with those of the Easy Button Mod project. Since the message in the clock will not be changed often, the buttons necessary to program the Windbond chip were placed on an external header. The round PCB for the voice module fits in the clock thanks to Sony's cubic design. The programmed voice module was screwed into the plastic housing for the alarm clock, the interface connected and the clock re-assembled.
The He-Man clock will now live on in the digital age (or at least until it drives me nuts and I'm forced to throw it across the room)!