Here’s a (hopefully) complete list of entries in the Open 7400 Competition. Please share your favorites in the comments below, your favorites will receive a special reader’s choice prize. Voting ends in 24 hours.
A few commentators will receive free PCB codes as a thank you for voting.
Check out the list below.
- TV Auto-off from the ’80s
- 4049 inductance meter
- DIY 6502 computer
- 4000 series CMOS 24 hour clock
- Telemetry Beacon for HAM Sats
- 4-bit SAR analog to digital converter
- Data encryption and decryption system using 74xx logic gates
- Hacky random number generator / cat toy
- Passive RFID Tag from 7400 discrete logic
- Random number generator
- Flickery LED bar candle
- Relative clock/timer/alarm
- Direct digital synthesis arbitrary waveform generator
- Mathemagic – Mind Reader
- 7400 ping))) pong
- 7400 Logic Based Calculator
- 1 bit microcontroller
- Fourbit, 4-bit homebrew CPU
- A game of Tic Tac Toe with logic IC’s
- Quiz Show Buzzer
- Bug shaped robot
- Lineclock
- DIY musical keyboard
- World’s most useless machine
- CMOS frequency counter
- Mr. @#?%!…A 74xx based Q*Bert-ese obscenity generator
- 7400 Dimmer
- The BrainF**k machine
- CD4000 digital alarm clock
- Using two CD4007 IC as an op amp to generate sine waves
- CMOS car alarm
- 40xx logic chips project
- Frequency counter
- A nixie-based Press Your Luck game
- Class D amplifier using digital logic
- The polonaise machine
- Periodic egg turner for incubator
- Constant load with nixie readouts
- A CPLD-based 8×8 game-of-life
- Signal strobe
- I2S DAC with a Class D amplifier output
- Build your own FPGA
- Animated LCD name tag
- Lighting effects generator
A huge thanks to everyone who voted. Judges are deliberating now, final results will be posted by November 10th.
My favorites (assuming I can’t vote for mine) are the constant load with nixie readouts, and the Class D amplifier using digital logic.
I’m a humongous fan of the passive RFID tag. It’s unbelievable both how much power you can get out of the reader and how little power the collection of logic chips consumes (go CMOS!)
However, I would have to throw a vote to the 4049 Inductance meter because it is a useful thing made out of really old tech that I now want to build!
The list can’t be this small, I wanted to vote for my friend who entered 2 projects, can I vote for projects not on the list. As I can’t see his projects here…..
I’d have to say the constant load with nixie readouts. It’s useful and the nixies are a nice touch.
My vote is for: Build your own FPGA
It shows how the basic unit of a FPGA works.
I vote for the 7400 Logic Based Calculaator
My favourite is Build your own FPGA. I think Nick should try 3D topology next!
Also, 4007 opamp is pretty awesome. I was thinking about doing it too!
My vote is for the The BrainF**k machine. Although the guy didnt actually built it, I found he made a very clever set of design choices.
The build-your-own FPGA was very instructive for me.
The passive RFID tag has to take the cake, I want to build one!
My vote goes to the 7400 Logic Based Calculator. :)
I’m torn between the sheer ingenuity of the Build Your Own FPGA and the Retro feel of the DIY keyboard.
All are awesome and I cannot choice only one :D
Simplicity : 4049 inductance meter
fun : Mr. @#?%!…A 74xx based Q*Bert-ese obscenity generator
usefulness : CMOS Frequency Counter
best effort : 7400 Based Digital Calculator
design : CD4000 Digital Alarm Clock
brilliant : Constant load with nixie readouts
complex : Data encryption and decryption system using 74xx logic gates
awesome : Passive RFID Tag from 7400 discrete logic
Discrete FPGA, definitely.
Since I’m to modest to vote for my own “Constant load with nixie readouts”…
I give my first vote to the awesome “Passive RFID Tag from 7400 discrete logic”
and the second to the definitely cool “Data encryption and decryption system using 74xx logic gates”.
I’ll vote for “Passive RFID Tag from 7400 discrete logic”
“Passive RFID Tag” is definitely the coolest one.
Obviously I am going to vote for my project “7400 Based Digital Calculator”, but I can also see some interesting project out there.
In the absence of a vote for my own Discrete FPGA project, I’ll vote for the 1-bit processor, for introducing me to the concept of bit-serial CPUs.
i give my first vote 2 Robot “MANTICORA” .. since i am interested in robotics … wooww
and also after checking 7400 Logic Based Calculator ,, i will choose 7400 as my first choice
and also after checking 7400 Logic Based Calculator ,, i will choose 7400 Logic Based Calculator” as my first choice
I’d go with “Passive RFID Tag from 7400 discrete logic”
Got to go with the passive RFID tag. A great example of sufficient overengineering
Passive RFID tag, definitely. Especially because it has such a slick end product.
Since I am more of an analog person, I was impressed by the the extreme measures of the Class D amplifier using digital logic (hasn0life) using buffers in parallel to get the necessary amount of output current.
I was blown away, however, with the “build your own FPGA”.
The circuit I want to actually replicate is the inductance meter, it might save me money :D
As for my own entry: Opamp made from 4007, there are still more possibilities to explore… (this is not voting)
Me vote goes of to Bertho with his Passive RF74xxID tag.
My vote is for 7400 LOGIC BASED CALCULATOR .
‘Build your own FPGA’ is really impressive. Complex work in both HW and SW.
I vote for 7400 LOGIC BASED CALCULATOR …..
I vote for the 7400 Logic Based Calculaator
My vote goes to ‘Build your own FPGA’ project…very cool project….help understand the fundamentals of FPGAs and how they work….
My vote goes to the 7400 Logic Based Calculator. :)
I vote for 7400 LOGIC BASED CALCULATOR
In this order: the home-grown FPGA, the DIY 6502 computer, and the 4bit SAR. And a special award to the BrainF**k machine :)
My vote has to go to the the DFPGA (“Build your own FPGA”), for not only an interesting project but also a fantastic writeup.
I will also vote for the “Build your own FPGA”. It’s a really awesome project and might be very useful for educational purposes.
I vote for 7400 LOGIC BASED CALCULATOR
I vote for 7400 LOGIC BASED CALCULATOR
I vote for 7400 LOGIC BASED CALCULATOR……
I vote for 7400 Logic based Calculator.
I vote for 7400 LOGIC BASED CALCULATOR
I give my vote to the homebrew FPGA.
Very nice design and gorgeous CMS build, well done !
I vote for 7400 LOGIC BASED CALCULATOR too
Im a great fan of the Passive RFID Tag, I love the mashup between old school logic and fancy modern RFID.
As a bonus the documentation is excellent and the end product is beautiful.
My vote is for the Constant load with nixie readouts. I think it was the nixies that did it for me and the fact that I need an other piece of equipment on the bench.
I vote for 7400 LOGIC BASED CALCULATOR
That RFID tag is mind blowing. I’m buying one if he ever decides to mass produce.. The FPGA thing is nice too, but the wildest over-engineering is most definitely the RFID.. (over-engineering is a good thing, haven’t you heard?)
I vote for the polonaise machine! It’s full of win and awesome.
My vote goes to the DFPGA. Great project and very good write up of it too.
I vote for 7400 LOGIC BASED CALCULATOR.
I found the discrete FPGA very instructive.
my vote goes to 7400 Logic based calculator, i know it is very good
I would vote for my own entry which is ‘Data Encryption and Decryption System using 74xx logic gates’..but if I have to choose another one, it would surely be ‘Build your own FPGA’..really awesome build Nick!! :)
CD4000 digital alarm clock gets my vote!
I vote for the 7400 Logic Based Calculaator
My vote goes to 7400 Logic based calculator.
My vote goes to the 7400 Logic Based Calculator. :)
my vote goes to 7400 Logic based calculator
Awesome idea… I vote for 7400 LOGIC BASED CALCULATOR… (Y)
my vote goes to 7400 Logic based calculator
I like mine of course, the CMOS Frequency Counter :) But I take my hat off to the Passive RF Tag’s creator who has done a tremendous good job in his circuit, I really like it! Nice design and idea!
Totally the RFID chip, most complete setup on the board
2nd the DFPGA, just because I like FPGAs so much :)
I’d like to vote to my 1 bit microcontroller :)
If it isn’t possible, my vote goes to “Build your own FPGA”
My Vote – DIY musical keyboard :)
I’ll cast my vote for the RF74xxID!
My vote goes to CMOS Frequency Counter.
My vote is for “7400 Logic Based Calculator”
i give my vote to 7400 Logic Based Calculator
My vote is 7400 logic based calculator…..!~!
after readings i want to vote for 7400 logic based calculator
The passive RFID tag! It is by far the most ambitious project this year.
After getting the know how i want to give ma vote to 7400 logic based calculator
7400 logic based calculator seems interesting and practical.
My vote is for “7400 based calculator”. these guys are genius !
My vote is for “7400 based calculator”.
7400 logic based calculator
I vote for the class D amplifier (cause I made it…)
My personal favorite though is the BrainF*ck Machine, I really like unusual computer architectures, and I think it’s great to have a “functional” computer using 20 readily available logic chips.
Of course, the other entries are also pretty amazing….
My vote goes to the 7400 Logic Based Calculator
my vote goes to 7400 Logic based calculator,because its more efficient and practical…
I vote for 7400 LOGIC BASED CALCULATOR
i vote for 7400 Logic based calculator,because its more efficient and practical…
vote for cmos frequency counter :)
I vote for CD4000 digital alarm clock for it’s design
My vote is for 7400 LOGIC BASED CALCULATOR
voting for 7400 LOGIC BASED CALCULATOR.nice use of 7400 series
My first place vote is for the DIY 6502 computer. For second place I vote for 7400 Logic Based Calculator. There are a lot of great entries!
I’m really impressed with the RFID tag. To even think of doing this is amazing!!!
(Guess I wish I had the time for engineering something so completely out of the ordinary (and useless ;-))
I vote for 7400 LOGIC BASED CALCULATOR
My vote goes to Data encryption and decryption system using 74xx logic gates.
i Vote for Data encryption and decryption system using 74xx logic gates
I vote for DATA encryption and Decryption …Really a great work… seems to be unique.
my vote is for ‘Data Encryption and Decryption System using 74xx logic chips’
My vote is for the excellent work on DATA encryption and Decryption
I vote for Data Encryption and Decryption System using 74xx logic chips’
amazing
i vote for Data Encryption and Decryption System using 74xx logic chip.
I would vote for my own entry which is ‘Data Encryption and Decryption System using 74xx logic gates’
I have seen your work behind this.. No one can think about it.. Awesome guys.. you did it…
Nakul,Nischal,Nikilesh.. its ultimate..
I would defenitely go for Data encryption and decryption using 74xx logic gates
“Data encryption and decryption system using 74xx logic gates” is the clear winner here .. My votes for that brilliant idea !
I vote for ‘Data Encryption and Decryption System using 74xx logic chips’
I Vote for ‘Data Encryption and Decryption System using 74xx logic chips’
I vote for “data encryption and decryption using 74xx logic gates”
“Data encryption and decryption system using 74xx logic gates” .. My votes for the best one !
I vote for 7400 LOGIC BASED CALCULATOR
Am I the only one who thinks there’s something hinky with the voting for a couple of the projects?
heh yeah, it says it was made by students so it looks like either it’s an entire classroom of people who worked on the calculator or just someone and then got the class to all vote on it
popularity contest, oh well
i liked most of the projects, my favorites were the q*bert, fpga, keyboard, and all the game projects.
i would have liked to see video of the dds, brainfuck, and some others that didn’t have video though
yep, all it took was one post on facebook and the whole class[and friends] came to vote – though the project was made by 2 [not me]
I hope this doesn’t scare off future contest participants from entering because they can’t (or don’t want to) get a group of people to vote for them. I also hope this doesn’t become a trend. Maybe there should be some kind of qualifications to vote? Also, were there judges this year?
We figured it was ok because anyone was welcome to recruit friends and family to vote. We did not however count the vast majority of votes that were put in the wrong place (eg on the entry instead of here).
There were 6 judges from the community this year, but we also included reader feedback in the ranking system and grand prize winner.
I would have preferred that only proper registered forum members could have voted out of fairness reasons. I’d say that the winner of the grand prize is on the very thin line between just following the rules set by DP and cheating. It would have been all to easy to make a small script that via TOR would have voted 4000 times with different names and ip addresses on my entry.
But since all of this is “just for fun” I really don’t care too much. I just hope that the winner make good use of his selected prize…..
I think it would have been fairer if only other competitors could vote for the reader’s. It’s easy to register on the forum just to vote, so I think enforcing forum register is not strong enough. Also It’s a bit sad that the most important voting category this year was indeed a popularity contest, with not to do with the criteria stated at the begin of the contest.
I’m sorry you were disappointed by the approach. I’ll definitely consider your suggestions if we every do something like this again.
If you’re in the mood for constructive criticism, my input:
– I don’t think Reader’s Choice was a bad idea, but when there’s few enough votes that a small group of legitimate voters (eg, a uni class) are enough to swing the vote, it’s going to be very prone to bias – less about the project, and more about who made it. That’s always going to be the case, but it’s more noticeable when the number of votes is small.
– I think the choice of the grand prize should have been left up to judges, not readers.
– I really would have liked to see more stratification in the prize levels. I realise one of the motivations was probably not to string out the process of giving out prizes too much, but I honestly think 15 first place winners is too many. It would have been much preferable if the judges had divided into categories with much more granularity.
– A short blurb from each judge about what they liked about this year’s entries, which entries particularly impressed them, what they thought was particularly novel, and so forth, would have been awesome.
All that said, thank you for running an awesome and inspirational contest. I’ve learned a lot both from building my own entry and reading about others’, so what more could I really ask for?
It is great to see student entries IMO especially from outside Europe and the USA – hearty congratulations to the winners!
In future I think it would be nice to have a separate student prize category mainly to stimulate entries from students but perhaps it might also help sidestep some of the classroom voting issues.
Thanks also to the anonymous judges on the forum.
Voting have already been ended. It would have no worth I think.
I vote for “Build your own FPGA” !!!! it rocks
I vote for the 7400 Logic Based Calculator
voting has ended , i guess :-p
I vote for 7400 LOGIC BASED CALCULATOR
I vote for circuit based on Cryptography.
Data encryption and decryption system using 74xx logic gates is the best among all these projects.I would definitely vote for it.
I vote for ‘Data Encryption and Decryption System using 74xx logic chips’
‘Data Encryption and Decryption’ using 74xx logic gates would be a good one. I vote for it….
I vote for Data encryption and decryption system using 74xx logic gates.
I vote for ‘Data Encryption and Decryption System using 74xx logic chips’
I vote for Passive RFID Tag
I vote for ‘Data Encryption and Decryption System using 74xx logic chips’