DaveHey hackers and on #hackadayio :
More SAO, less SEO! Please!
I'm following 361 people on #hackadayio and the only one I see (constantly) updating projects is @deshipu and max other person is in a feed with an update.
Other updates in my feed include:
- Spam comments on other peoples projects
- people complaining about messages from companies for contests
- people following a list (nobody cares)
hackaday unofficialI2C Tap Helps Assign Blame For SDA Conflicts
If you've ever debugged a misbehaving I2C circuit, you probably know how frustrating it can be. Thankfully [Jim] over at Hackaday.io, has a proto-boardable circuit that can help!
Inter-integrated circuit bus (aka I2C) uses open collector outputs on a two wire interface. Open collector means a device connected to the I2C bus can only pull the bus down to ground. Chips never drive a logic "HIGH" on the wires. When nothing is driving the lines low, a weak resistor pulls the lines up to VCC. This is a good thing, because I2C is also a multidrop bus -- meaning many devices can be connected to the bus at the time. Without open collector outputs, one chip could drive a high, while another drives a low - which would create a short circuit, possibly damaging both devices.
Even with all this protection, there can be problems. The SCL and SDA lines in the I2C communication protocol are bidirectional, which means either a controller or a peripheral can pull it low. Sometimes, when tracing I2C communications you'll need to figure out which part is holding the line low. With many devices sharing the same bus, that can become nigh-impossible. Some folks have tricks with resistors and analog sampling, but the tried and true method of de-soldering and physically lifting chip pins off the bus often comes into play.
[Jim's] circuit splits SDA signal into controller-side and peripheral-side, helping you make it clear who is to blame for hiccups and stray noise. To do that, he's using 6N137 optoisolators and LMV393 comparators. [Jim] shared a NapkinCAD schematic with us, meant to be replicate-able in times of dire need. With this design, you can split your I2C bus into four separate channels - controller-side SDA, peripheral-side SDA, combined SDA and SCL. 4 Channels might be a lot for a scope, but this is no problem for today's cheap logic analyzers.
The circuit is rated for 100KHz debugging, but if it doesn't work for your 400KHz (or higher) bus, you can always lower the speed. This kind of monitor is useful for taming devices going rogue, and it isn't technically limited to SDA splitting! I2C also has a feature called clock stretching, where prehiperals are are allowed to manipulate the SCL line, too. In case of clock stretching-related problems, you can swap the SCL and SDA lines, which will allow you to use [Jim's] circuit on SCL.
It absolutely wouldn't be hard to assemble a device like this when you're really stuck with a tricky I2C situation. What kind? We've talked about all the possible I2C problems in a long-form article of ours!
#microcontrollers #toolhacks #debugging #debuggingtools #hackadayio #i2c
Tracer, A Platform For All Things Movement Logging
[electroSwing] is building a lightweight, battery-powered board to track and measure movement of all kinds, called Tracer. Powered by an ESP32, it has a LSM6DSL 6DoF accelerometer & gyroscope sensor, and a VL53L0X Time-of-Flight sensor. A small Li-ion battery in a holder reportedly provides for 5 hours of streaming data over Bluetooth Low Energy (BLE) at 100 Hz. It's essentially a wireless movement sensor platform to be paired with a more powerful computer for data logging and analysis. What's such a platform good for?
They show it attached to a tennis racket, saying you could use the data to, for a start, count the strokes done in a given match. They've also strapped it to a bicycle's crankshaft and used it as a cadence sensor - good for gauging your cycling efficiency! But of course, this can be used in more applications than sport. A device like this could be used for logging movement of any relatively nearby objects, be it your cat, an office chair, or a door someone might slam a bit too hard at times. Say, you wanted to develop a sleep tracker and were to collect some data for defining your algorithms and planning your hardware requirements - this would work wonders.
There's already available example code for streaming data into the Phyphox data logging and graphing app, as well as schematics - hopefully, the full board files will be available soon. A worthy open-source opponent to commercial devices available for similar purposes, this platform is good news for any hacker that wants to do motion measurement projects without reinventing quite a few wheels at once. We are told this board might get to CrowdSupply soon, and we can't wait! Platforms like these, if done well, can grow an offspring of new projects for us to have fun with, and our paid projects get all that much easier to work on.
We've shown projects with such sensors before - here's one that helps your rifle aim by giving you data to debug your last-second rifle movements, and another that logs movement data from inside a football. There's a million endpoints you could stream your data into, and we are told you could even use Google Sheets. Just a year ago, we held our Data Logging contest and the entries we received will surely point out quite a few under-explored areas in your daily life!
#wearablehacks #ble #bluetoothle #datalogger #datalogging #esp32 #hackadayio #lsm6dsl #vl53l0x #wearable #wearables
Say Friend And Have This Box Open For You
Handcrafted gifts are special, and this one's no exception. [pender] made a Tolkien-inspired box for his son and shared the details with us on Hackaday.io. This one-of-a-kind handcrafted box fulfills one role and does it perfectly - just like with the Doors of Durin, you have to say 'friend' in Elvish, and the box shall unlock for you.
This box, carefully engraved and with attention paid to its surface finish, stands on its own as a gift. However, with the voice recognition function, it's a project complicated enough to cover quite a few fields at once - woodworking, electronics, and software. The electronics are laid out in CNC-machined channels, and LED strips illuminate the "Say Friend And Come In" inscriptions once the box is ready to listen. If you're wondering how the unlocking process works, the video embedded below shows it all.
Two solenoids keep the lid locked, and in its center is a Pi Zero, the brains of the operation. With small batteries and a power-hungry board, power management is a bit intricate. Two capacitive sensors and a small power management device are always powered up. When both of the sensors are touched, a power switch module from Pololu wakes the Pi up. It, in turn, takes its sweet time, as fully-fledged Linux boards do, and lights up the LED strip once it's listening.
[Pender] didn't want to go for any cloud-based voice recognition service - such a gift requiring a pre-established WiFi connection would be no fun at all. Instead, he set up and used PocketSphinx for offline voice recognition. The box is a surprise for his son, thus, [pender] couldn't quite ask for voice samples. Thankfully, PocketSphinx recognizes phrases without pre-training. There's also a contingency mechanism - the electronics aren't accessible until you open the box. The secret is to apply voltage to two pads, which will unlock the solenoids directly, just in case the battery dies or the Pi glitches out.
We don't quite know what awaits when the box is opened, but we can only hope that the son's name isn't Balin. We thank [pender] for documenting the details, as a reminder that our hacker skills let us build unique and beautiful things for the people we value. Hacker-built gifts are great - we've seen guestbooks for weddings, couple's proximity sensing LED badges, ESP32-based CTFs, and even meteorite turntable display stands.
#art #raspberrypi #hackadayio #pocketsphinx #powermanagement #voicerecognition #woodworking
Announcing: The 2022 Hackaday.io Sci-Fi Contest
Ladies and Gentlemen, Sentient robots, Travellers from the distant future, or Aliens from the outer rim, it's time to enter the 2022 Hackaday.io Sci-Fi Contest!
We last ran the Sci-Fi contest in the far, far past -- before the Voigt-Kampff machine was detecting replicants on the gritty streets of 2019's LA. Back then, we had some out-of-this-world entries. It's time for the sequel.
Thanks to Digi-Key, the contest's sponsor, your best blaster, your coolest costume, or your most righteous robot could win you one of three $150 shopping sprees in their parts warehouse. Create a Hackaday.io project, enter it in the contest, and you're set. You might as well do that right now, but the contest closes on April 25th.
Sci-Fi is all about the looks, so if it's purely decorative, be sure to blind us with science (fiction). If your project actually functions, so much the better! Of course we'd like to know how it works and how you made it, so documentation of the project is the other big scoring category. Whatever it is, it's got to be sci-fi, and it's got to have some electronics in it.
If you're looking for inspiration, you could do a lot worse than to check out [Jerome Kelty]'s Animatronic Stargate Helmet, that not coincidentally took the grand prize last time around. It's an artistic and engineering masterpiece all rolled into one, and the description of how it's made is just as extensive. [Jochen Alt]'s "Paul" robot isn't out of any particular sci-fi franchise that we know, but of rolling on one ball and reciting robot poetry, it absolutely should be.
Honorable Mentions
In addition to the overall prizes, we'll be recognizing the best projects in the following honorable mention categories:
- Star Star : Whether you’re “beam me up” or “use the force”, fans of either of the “Star” franchises are eligible for this honorable mention.
- ExoSuit : This category recognizes sci-fi creations that you can wear. Costumes and armor fit in here.
- Stolen off the Set : If your blaster looks exactly like Han Solo’s, you’re a winner here. This is the category for your best prop replica.
- Living in the Future : If your sci-fi device was purely fantasy when imagined, but now it’s realizable, you’re living in the future. A working tricorder or a functioning robot companion would fit in fine here.
- The Most Important Device : Has no function, but it certainly looks like it does. Just blinking lights that blink back and forth, yet the government spent millions of dollars on it.
You don't have to tell us where your project fits in. We've got you covered.
Engage!
Get started now by creating a project page on Hackaday.io. In the left sidebar of your project page, use the “Submit Project To” button to enter in the 2022 Sci-Fi Contest.
You have from now until April 25, 2022 to get it finished. Of course, if your time machine actually works , you can finish it whenever. Check out the Hackaday.io contest page for all the fine print.
#contests #hackadaycolumns #contest #costume #hackadayio #prop #robot #scifi #sciencefiction #spaceship
Ethernet Tester Needs No LEDs, Only Your Multimeter
Ethernet cable testers are dime a dozen, but none of them are as elegant and multimeter-friendly as this tester from our Hackaday.io regular, [Bharbour]. An Ethernet cable has 8 wires, and the 9 volts of easily available batteries come awfully close to that - which is why the board has a voltage divider! On the 'sender' end, you just plug this board onto the connector, powered by a 9 volt battery. On the "receiver" end, you take your multimeter out and measure the testpoints - TP1 should be at one volt, TP2 at two volts, and so on.
As a result, you can easily check any of the individual wires, as opposed to many testers which only test pair-by-pair. This also helps you detect crossover and miswired cables - while firmly keeping you in the realm of real-life pin numbers! This tester is well thought-out when it comes to being easily reproducible - the PCB files are available in the "Files" section, and since the "receiver" and "sender" PCBs are identical, you only need to do a single "three PCBs" order from OSHPark in order to build your own!
Bharbour has a rich library of projects, and we encourage you to check them out! If you ever want to get yourself up to speed on Ethernet basics, we've talked about its entire history - and we've even explained PoE! After some intensive learning time, perhaps you can try your hand at crimping the shortest Ethernet cable ever.
#networkhacks #toolhacks #cabletester #continuitytester #ethernet #ethernetjack #hackadayio #networktester
Reusing Proprietary Wireless Sockets Without Wireless Hacking
Bending various proprietary devices to our will is a hacker's rite of passage. When it comes to proprietary wall sockets, we'd often reverse-engineer and emulate their protocol - but you can absolutely take a shortcut and, like [oaox], spoof the button presses on the original remote! Buttons on such remotes tend to be multiplexed and read as a key matrix (provided there's more than four of them), so you can't just pull one of the pads to ground and expect to not confuse the microcontroller inside the remote. While reading a key matrix, the controller will typically drive rows one-by-one and read column states, and a row or column driven externally will result in the code perceiving an entire group of keys as "pressed" - however, a digitally-driven "switch" doesn't have this issue!
One way to achieve this would be to use a transistor, but [oaox] played it safe and went for a 4066 analog multiplexer, which has a higher chance of working with any remote no matter the button configuration, for instance, even when the buttons are wired as part of a resistor network. As a bonus, the remote will still work, and you will still be able to use its buttons for the original purpose - as long as you keep your wiring job neat! When compared to reverse-engineering the protocol and using a wireless transmitter, this also has the benefit of being able to consistently work with even non-realtime devices like Raspberry Pi, and other devices that run an OS and aren't able to guarantee consistent operation when driving a cheap GPIO-operated RF transmitter.
In the past, we've seen people trying to tackle this exact issue, resorting to RF protocol hacking in the end. We've talked about analog multiplexers and switches in the past, if you'd like figure out more ways to apply them to solve your hacking problems! Taking projects like these as your starting point, it's not too far until you're able to replace the drift-y joysticks on your Nintendo Switch with touchpads!
#homehacks #wirelesshacks #analogswitch #hackadayio #homeautomation #reverseengineering #rfremotecontrol #smarthome #wirelessoutlet
iPod Mod Puts Pi Zero in New Bod
We sure love to see nicely designed products get a new lease on life. Just as the new Raspberry Pi Zero 2 was being announced, [production] was stuffing an original RPi Zero into an old iPod’s case.
[production] cites several previous, similar projects that showed how to interface with the click-wheel, a perfectly fitting color display from Waveshare, and open-source software called Rockbox to run on the pi. We all stand on the shoulders of giants.
Some nice innovations to look for are the Pi Zero’s micro-SD card and a micro-USB charging port aligned to the large slot left from the iPod’s original 40 pin connector. Having access for charging and reflashing the card without opening the case seems quite handy. There’s a nice sized battery too, though we wonder if a smaller battery and a Qi charger could fit in the same space. Check the project’s Hackaday.io for the parts list, and GitHub for the software side of things, and all the reference links you’ll need to build your own. It looks like [production] has plans to turn old iPods into Gameboy clones, you may want to check back for progress on that.
If you just want to rock like it’s 2004, there are options to just upgrade the battery and capacity but keep your vintage iPod too.
#ipodhacks #portableaudiohacks #raspberrypi #github #hackadayio #ipod #portableraspberrypi #raspberrypicase #raspberrypizerow #rasperrypizero #rockbox #waveshare
An Inexpensive FM Receiver for the Raspberry Pi
At this point, there are no shortage of impressive hacks for the Raspberry Pi. [Dilshan Jayakody] recently documented his experience in designing and building an inexpensive FM Stereo Receiver for the Pi platform, and the results are impressive.
Quite a few FM receiver projects center around the RDA5807 or TEA5767 ICs, however [Dilshan] has used the QN8035 by Quintic Corporation in his build. A handful of discrete components on a pleasing single-sided PCB is all that is needed to interface the QN8035 with the Pi's I2C bus.
After demonstrating that the FM tuner could be, well, tuned at the command line, [Dilshan] then coded a smart looking GUI application that makes tuning a breeze. The software allows the listener to manually and automatically scan through FM stations, decode program service data, control the volume, and display the RSSI and SNR readings from the tuner.
As we reported earlier, FM radio is on a slow decline into obsolescence. This latest project isn't aiming to break new ground, however its simplicity and inexpensive components are the perfect combination for beginner hackers and radio enthusiasts alike. More details can be found over on Hackaday.io. The schematic, source code and bill of materials can be found on GitHub.
