Have you ever seen a pocket calculator for 1970?
If you do, you know a lot of people use a series of red LED 7-
Segment Display.
These displays use a small number of "light bars"
Light-emitting materials placed behind small enlarged bubbles make them easier to see.
They are very clear and easy to read, and the power used is much lower than the vacuum fluorescent display (VFD)
Also used at that time.
I remember the small LED bubble display used to be among the various handheld electronics, and the form of the watch was slightly different.
By the end of 1970s when LCD monitors became cheaper, more electricity
Hungry? the LED display is out.
Back in 2011, I was pleasantly surprised to find an HP 5082 seller on ebay.
LED display 7433.
This is three.
Digital Display in 12-
PIN standard DIP format.
I bought some tracks because the price was good.
I tend to get the "thing" and then never use it, so I decided to have a project this time to take advantage of all the monitors.
The "Tnychron" clock was born!
Design Requirements :-1970s-
Vintage box
Arduino IDE environment project-
Use HP display effectively-
Let it play music
Make it easy for useI to settle on Serpac a20.
The initial layout test in Eagle shows that there is enough space inside the PCB.
The only downside to this situation is (
Probably in most cases)
Is pre-choice
Front window-
Transparent or black/IR transparent.
I wanted the red one so I found a 1/16 acrylic sheet supplier online and ordered some.
I used a small table saw with a very thin pitch blade on it to cut the plastic.
The measurements are obtained from the Serpac spec sheet and the PCB size is confirmed by the exported image.
Brd file, punch the mounting hole out and make sure the hole matches the mounting rod and meets all the requirements of the mounting rod.
This project uses Arduino 1. 0. 1 IDE.
I found that some of the libraries I use need some rewriting to be compatible with 1. 0.
I have provided them with project sources and Eagle. brd and .
Sch files on my github Website: these libraries may have been updated since I last used them.
But if you only need these, you can be sure that the content on my github site will work.
This is a photo of the bread plate prototype.
So a big problem with the clock is that the board is horizontal, but the display needs to be vertical so you can see them through the window.
How do I install them?
My first thought was to use machining. pin, right-angle sockets.
Good, but expensive. 7$ each!
I'm not going to put the $14/clock on the display socket so there has to be another way.
The better solution is to bend the lower display pins so that they are parallel to the back of the display and then weld the wires from the top line of the board to the top line of the display. Zero-
The ohm resistance is just in size for easy welding.
You can see in the photo below how I used gaffer's tape to protect things.
Gaffer's tape looks like "tape", but it is very different because it is designed to be strong, but there is almost no residue at the time of stripping.
I want a music alarm clock.
I never liked the "beeps ". . . beep. . . " alarms.
But how can I play music without disturbing the display of update or button events?
The answer is the excellent Playtune Library. (
On the ATMEGA328p used in the project, it is able to make three sounds at the same time.
Generate sound using a hardware timer (
Suitable voltage divider and voltage divider)
It's a Square without any envelopes.
The advantage of this approach is that once you have a timer configured, it will run and your code is free to do whatever else is needed until the next note event.
It would be tedious to enter notes manually, so there is a MIDITONES tool for converting. mid into code.
It has some useful options to limit simultaneous notes in the source file to make the most of the sound available.
I actually only use two of the three possible channels.
This is because I want to keep timer0 for Miriam ()
Timing and other functions.
It turns out, playtune.
Cpp actually includes an alternative timing function that allows a third sound.
Oh, well, things to remember.
The sound output by the timer is sent through a 500 ohm resistor and then directly to the large piezoelectric disc.
The combination of the drive, hole and housing cavity helps to strengthen the sound.
It must be big enough to wake you up from the bedside table or even across the room.
Almost all of the coding work of the project is used to make menus and set up systems for different parameters :-time-date-alarm-12/24 hr-
Daylight saving time
Set the default value three buttons are all the buttons installed on the back while leaving room for the power jack.
This is good for reducing, adding, and setting.
Data validation is performed for each menu item.
Another code design function is to use the display buffer.
Displayed as 8 characters (
Physically 9 but I don't use the last number)
But the buffer is 16, allowing the date to be stored.
The actual display function grabs the window from the display buffer.
This allows the time to scroll beyond the way the date is displayed, for a few seconds at the same time (
And everything else)
Keep updating.
The most important thing for me is to have an alarm clock that knows not to go out on weekends.
Alerts can be configured to be closed from never, on weekends only, on weekdays only or daily.
Here are some photos of the menu options.
Physically speaking, I made the rear panel the most difficult.
With the tools I can use, there is no ideal way to cut the rectangle of the power jack.
I was unable to move the Jack back due to the battery stand, so I was not able to use a normal drill hole.
I created a template to help me accurately mark the back plate for drilling.
As for the power jack hole, it is better to turn around the profile with a small bit, cut it out using a wire cutter, and then archive the sides to make it smooth and even.
In terms of hardware, this is what is in the clock: timing at 16 mHz with external crystalds307 RTC chip and 32 kHz crystal1220 battery and 12mm battery holder at 16 mHzcathode, 7-
Segment Display driver I realize you might be able to do the same with only the ATMEGA328p.
This will be more coding work and I don't think you will have the same battery life as you would have gotten from ds307.
This is my first project using Eagle CAD and PCB fab house BatchPCB.
Both Adafruit and Sparkfun provide great parts libraries for Eagle, which makes it very easy to build the board, thus avoiding the fact that you have to design the parts yourself.
BatchPCB does a good job
I found only one small flaw in 20 boards.
Random copper "hairs" on a small portion of the board, resulting in short.
It's easy to get it done with an exacto knife.
The final board layout has been revised three times.
At first, I somehow reversed the display line;
The next day, I realized that the switch Holder was not very suitable for the right --angle switches;
The third is charm.
I have enough monitors to make 10 clocks.
At the time of writing this manual, I still have 6 pieces left and 9 extra boards (
Note: the shopping cart for BatchPCB may say "quantity 1" but that still means two boards).
Send me a personal message if you want to buy a clock or light board.
If there is no same Display (
Or can't find them anywhere)
Of course you can open any ordinary one with my board-cathode 7-
LED display.