Working on an enigma project - please recommend a noise type device... - Page 1
Forum section: electronics / projects

author: alank2
author_rank: Super Contributor
timestamp: January 26, 2016, 06:52:51 pm
content: It will be a 10cm x 10cm pcb with a keyboard, ledboard, and 4 5x7 LTP305's for the indicators. I'm going to drive it with an ATMEGA165 or ATMEGA325 and a HT1632C for the LTP305's. One thing I hadn't thought about is that it would be nice to have a small simple noise maker device for key presses that could also be used perhaps for a longer duration to indicate an error selection, etc. I'm used to using an active buzzer type of piezo, but they are too loud for what I want. I'd like to drive it from a simple GPIO pin. Any ideas or recommendations?I've attached a rough mockup (key's aren't positioned correctly, etc.) as an example of what I hope to do with the project.

author: pmbrunelle
author_rank: Regular Contributor
timestamp: January 27, 2016, 01:27:55 am
content: You could make a relay click on keypresses.How will the code wheels and plugboard configuration be securely stored?

author: alank2
author_rank: Super Contributor
timestamp: January 27, 2016, 01:46:39 am
content: The relay idea is interesting.I was originally thinking of storing the machine configuration in the AVR EEPROM (protected by its lockbits), but I'm not sure I even want to do that. I may just store the machine configuration in sram and a power off or key combination will clear it.

author: Len
author_rank: Frequent Contributor
timestamp: January 27, 2016, 01:50:05 am
content: You can make clicks & beeps with a simple piezo element (no internal oscillator or anything) connected directly to a GPIO pin. The volume is about right for key-clicks, in my experience. There's more info here:https://learn.adafruit.com/ice-tube-clock-kit/design(near the bottom of the page)

author: helius
author_rank: Super Contributor
timestamp: January 27, 2016, 01:52:24 am
content: Quote from: EEtimes link=http://www.eetimes.com/document.asp?doc_id=1195875

author: uncle_bob
author_rank: Unknown
timestamp: January 30, 2016, 11:19:50 pm
content: HiOnce you have the piezo gizmo, there is no need to stick with simple "single transition" drive. The thing is a speaker. It's not a very *good* speaker. You can fiddle around with what you hit it with (PWM or whatever) to tune the result to your liking. Will it sound way lots better? Nope. Can you improve things a little - sure. The trick is to put it on a pin that can be driven easily at audio speed while you still are in the schematic stage.Bob

author: rich
author_rank: Frequent Contributor
timestamp: January 30, 2016, 11:38:47 pm
content: Vibration motor from a mobile phone? - Surely an electronic enigma needs at least some haptic feedback for authentic reference back to the original(This idea was totally inspired by pmbrunelle's relay thinking above.)

author: Muxr
author_rank: Super Contributor
timestamp: January 31, 2016, 12:09:05 am
content: Quote from: rich on January 30, 2016, 11:38:47 pmI second this, short vibration and a relay click would make it feel very steam punky.

author: alank2
author_rank: Super Contributor
timestamp: January 31, 2016, 01:41:51 am
content: Quote from: Muxr on January 31, 2016, 12:09:05 amI agree that is a good idea. I've got the piezo working pretty well now - it can make a nice tick type noise and a low 100 Hz buzz error type noise which is all I need, but I'm going to try some cell phone vibrators and some relays to see how they sound and feel too.

author: alank2
author_rank: Super Contributor
timestamp: February 06, 2016, 05:01:32 pm
content: Both the pcb and firmware are coming along.This is the first round of the pcb, I have to fix all the silk screen and add more ground via's and generally clean up and optimize tracks, but it looks pretty good for a start.Using oshpark as a viewer here - I'm going with black or maybe even elecrow's matte black for the soldermask.Almost all of the pins on the AVR are GPIO so that made routing easier.

author: HAL-42b
author_rank: Frequent Contributor
timestamp: February 06, 2016, 05:12:30 pm
content: You might even put a steckerboard if you feel like it.

author: alank2
author_rank: Super Contributor
timestamp: February 06, 2016, 05:20:54 pm
content: It is going to support the Stecker, UHR, and Rewireable D reflector in software. I wanted to keep the size go 10cm x 10cm.

author: retrolefty
author_rank: Super Contributor
timestamp: February 06, 2016, 07:40:22 pm
content: Quote from: rich on January 30, 2016, 11:38:47 pm++1I wonder with the ton of stuff published on the enigma if anyone ever described (or have recorded) the actual sound the unit may have made. A simple cheap WAV file player could make it sound however one wants.I worked on a more modern version in the U.S. Air Force during the sixties, the KL-7, an off-line crypto machine and the noise it made as if shifted the rotors with each keystroke was way cool.https://en.wikipedia.org/wiki/KL-7

author: uncle_bob
author_rank: Unknown
timestamp: February 09, 2016, 12:09:23 am
content: Quote from: retrolefty on February 06, 2016, 07:40:22 pmHiThere are indeed recorded sounds of each key .... they will be declassified in about 500 years=====There are a surprisingly large number of machines still out public hands. They are not exactly cheap, but they do exist. I'd bet somebody has a video of one doing it's thing.Bob

author: alank2
author_rank: Super Contributor
timestamp: February 09, 2016, 01:34:14 am
content: I actually found this -http://www.enigma-replica.com/enigmasound.html

author: uncle_bob
author_rank: Unknown
timestamp: February 09, 2016, 01:42:30 am
content: HiI bet somebody has a real one out there. I doubt it sounds noticeably different than the replica. To the extent that things like the case get into the act, there were multiple configurations in that respect.Bob

author: lpaseen
author_rank: Contributor
timestamp: February 15, 2016, 08:29:53 pm
content: I'm also working on an electronic enigma replica (http://lpaseen.blogspot.ca/2015/09/electronic-enigma-replica.html) and in my hunt for sound I found a few youtube videos that has a somewhat clean sound of the key pressing that can be extracted. Was first thinking of somehow make the sound directly from the arduino but realized that besides trickiness of making good sound with a single pin it also needs a lot of space for the data - something that is not to much of on the arduino. Adding something external like a sd card or more eeprom can be done but then it's much easier to just add a small external mp3 module that has a sdcard already and all you need to do is tell it what file to play and how loud./ps

author: alank2
author_rank: Super Contributor
timestamp: February 15, 2016, 08:33:49 pm
content: Very nice project lpaseen! Excellent!

author: alank2
author_rank: Super Contributor
timestamp: February 26, 2016, 04:44:53 am
content: Made up a prototype one today. Other than the HT1632C being an older version of the IC (1-2mm larger! I had to cut the legs) and a defective AVR (brand new, I had to use hotair to remove it and put another one on), it came together in the end. The displays look perfect in the real even though they are too bright in the picture. Probably the coolest thing I've made for fun. The piezo works great. I need to finish the firmware, but now I've got a nice prototype to work on instead of the messy breadboard setup.

author: rich
author_rank: Frequent Contributor
timestamp: February 26, 2016, 05:46:21 pm
content: Really nice, I love those displays they really match the style of the project and the sexy black solder mask works a treat

author: alank2
author_rank: Super Contributor
timestamp: February 26, 2016, 06:45:25 pm
content: Thanks Rich. Here is a better picture of the displays. I'm going to go with Elecrow's matte black for the final one.

author: alank2
author_rank: Super Contributor
timestamp: June 02, 2016, 12:54:47 pm
content: Matte black didn't work out so well, the silkscreen is much more faded and has breaks through it. It was disappointing, perhaps 7 out of 20 boards useable. The regular black silkscreen looks good.Here is a final picture of the project, I finally got the CNC to cut some oak to hold it.

author: rich
author_rank: Frequent Contributor
timestamp: June 03, 2016, 01:17:16 am
content: Nice work, the oak really adds a touch of class to the finished projectShame about the silkscreen issue - I've had varying quality of silkscreen from elecrow on different runs of the same design so it may not be directly related to the matt/normal black solder mask choice.