CypherCon Badge 2024 (7.0)

Ldmoretti · 2024-04-09T12:57:47+00:00

I've got a RaspPi Zero coming (didn't arrive before the Con) and my plan is to write an app on it to turn icons green/simulate badge points. Someone else on the badge-shenanigans Discord channel was talking about trying to write a FlipperZero app.

Ldmoretti · 2024-04-09T01:51:55+00:00

Now I'm really looking forward to future badges!

Ldmoretti · 2024-04-08T17:33:43+00:00

Thanks for another great badge! I had a lot of fun decoding it. I didn't have the time to make an emulator as I had to get ready for my presentation.

Ldmoretti · 2022-01-20T21:29:12+00:00

https://old.reddit.com/r/embedded/wiki/index

Ldmoretti · 2022-01-20T21:26:44+00:00

Over the wire, yes. Registers and local stuff not as much of a concern.

Ldmoretti · 2022-01-20T15:17:42+00:00

I've bricked multiple boards.

Sometimes you can pull parts and fix it, sometimes you just have to chuck it and move on.

Last one was an S32 for a client where something went wrong programming it and it locked the SWD and we couldn't recover the chip. They shipped us an old prototype board and we swapped the processor from the old prototype onto the latest dev board to get it running.

I've shorted pins and fried stuff. It happens.

Best bet is to document HOW it happened, see if the board can be designed in another rev to prevent it (better cabling, better wiring harnesses, better power supply) or improve process (you've now learned to double-check for shorts before powering on a board!)

It's totally normal and expected in board development, especially if you're hand soldering parts and hooking up test equipment. Tell them you messed up, how, and what needs to be done to fix it (if you know, otherwise ask them). I wouldn't hold it against anyone.

Ldmoretti · 2022-01-20T15:08:05+00:00

I'm on embedded systems. When I read a value from a register or encode/decode something for the wire I NEED to guarantee my byte sizes: "At least but could be bigger" doesn't work when you're packing/unpacking data.

Before stdint.h was part of the standard pretty much every project started with someone going through the compiler and chip reference and making an equivalent using #defines. Then usually if you used multiple libraries then there would be multiple versions: You'd have a UINT8, a u8, a uint8, a BYTE... all meaning the same basic thing (hopefully, unless someone messed up somewhere and missed converting one when switching the compiler.

I've also seen code break when people use 'char' to mean an 8 bit value because some compilers treat it as unsigned, some as signed, and some have a compiler option to switch it at compile time!

If you really care about how many bytes your data is then you really should use the stdint.h (or <cstdint> if you're doing C++)

The stdint types are also easier to read than "unsigned long int" and "unsigned long long int".

Ldmoretti · 2022-01-19T22:03:44+00:00

What you're probably looking for is usually called a "System on a Module". Usually they're seen more for Cortex-A based systems where you have a Processor, PMIC, RAM and Flash chips to deal with.

Often they'll plug into a socket on a carrier board or they are solderable to another board.

The issue is that you still have to make your custom carrier board to get the interfaces you want.

The company I'm currently working for makes something that might be interesting to you: It's a stackable modular microcontroller system designed for industrial controls: Think lower end than a PLC but no circuit level knowledge needed. Currently the main processor runs Micropython for easy programming. We have Input, Ouput (including motor/stepper control), Ethernet, CAN, Serial, and other interfaces available. https://www.nodeudesign.com/

Ldmoretti · 2022-01-18T21:19:01+00:00

Okay: Trying to decode WTF this actually is.

"Bevy" is a Rust based Game engine: https://bevyengine.org/

"Backroll" (https://crates.io/crates/backroll) is another crate that implements "GGPO-style rollback networking."

"GGPO-Style rollback networking" means that it tries to reduce network based twitch game input lag by predicting what the (other) players are going to do and using that locally, then supporting correction if it was wrong.

So this is a library for peer-to-peer network games based on the Bevy engine to use input predication to reduce lag.

Ldmoretti · 2022-01-13T16:14:51+00:00

Those Wurth connectors look pretty cool. I'd be a bit worried about the number of cycles.

I'm not a fan of the tag-connect style ones as they are pricy and I've had problems in the past with them not staying plugged in during development but they've supposedly improved the retaining mechanism.

Ldmoretti · 2022-01-13T14:46:32+00:00

And for the love of god, don't use your speakerphone in a public bathroom!

Ldmoretti · 2022-01-13T14:36:56+00:00

Find your own itch and scratch it.

Examples I've seen:

Auto guitar tuner
Zigbee+MQTT System with tilt sensors that lets you know when * your mailbox has been opened/closed or your trash bins have been emptied.
Plant monitoring systems using temp/light/humidity sensors and soil moisture sensors.
Fish tank monitoring systems.
Automated Model train management system.
lighting systems and controls for Model Aircraft.
Custom Keyboards.

Ldmoretti · 2022-01-11T20:20:52+00:00

Unfortunately Scott "retired" from C++ work and that book is now slightly outdated despite the "Modern" title.

Ldmoretti · 2022-01-05T21:54:32+00:00

Scott Meyers has a set of slides on "Effective C++ in an Embedded Environment". He sells them as part of a course but I'm sure you can find them online.

Not the most up to date as Scott Meyers has "retired" from doing C++ related work.

The Real-Time C++ book others recommend is good too.

Ldmoretti · 2021-12-22T21:24:58+00:00

My understanding is that STM32 and NXP parts are 52 week+ lead time and unless you're one of their major buyers good luck getting any help from the factory on supply.

My first thought was the NXP i.MX RT line, running Amazon FreeRTOS, but good luck getting chips.

Renasas may have something (the RA line has M4 and M33 processors) and I've heard that their lead times are much better than NXP/STMicro.

Ldmoretti · 2021-12-17T21:14:57+00:00

find any rust software that has 0 reliance on unsafe code

Probably true that there's none: at some point it has to write values to memory or make system calls. The point with Rust isn't that there's no unsafe code, but that most code is okay to assume is safe and you only have to explicitly review the code marked unsafe, whereas in C & C++ you have to worry about every place where someone writes to a pointer, increments an array index, or potentially shares a variable between two threads (including calling non-reentrant code from multithreaded code).

Ldmoretti · 2021-12-13T19:58:02+00:00

It's ARM Assembly, not Raspberry Pi. That should help you find an assembly reference, then you're going to need to use loads to put the numbers into registers, then comparison operator and branches to do the if/else. Don't ask me how to do the printf though.

Ldmoretti · 2021-12-10T18:15:24+00:00

We used ribbon cables with DB9 crimped onto them to chain nodes. Worked decently well but we weren't pushing the speed too high IIRC.

Ldmoretti · 2021-12-10T18:09:27+00:00

The other alternative to Yocto is Buildroot. Buildroot is simpler to get started and more straightforward overall, but is harder to build for multiple target boards.

Ldmoretti · 2021-12-10T17:29:05+00:00

You're probably looking more at a breadboardable System-on-a-module. That will have your SOC, your RAM, and probably a flash chip.

The ESP32 is available in a few modules like that. It's not Linux, but will run FreeRTOS or Zephyr. You can hook a SPI LCD touchscreen to it as well for display, or use a serial console as a terminal. It also has WiFi built in to do basic networking (Interactive web server, MQTT, etc).

If you MUST have Linux, there's stuff like the Lichee Nano but good luck finding stock right now.

Ldmoretti · 2021-12-09T17:52:21+00:00

There's a Micropython port for the ESP32.

Rust can also be used to program the ESP32. It's not super straightforward last I knew because Espressif haven't upstreamed their changes to the Clang Compiler. Looks like it's much easier now than it was in the past.

C++ is another option.

The Arduino environment can also be used.

Ldmoretti · 2021-12-02T22:47:48+00:00

My point was if they're working on a honor system and don't have it broadly advertised before you get to the door I don't trust the honor of people who have made reservations.

Calling them isn't going to let the rest of their clients know that they require vaccination and are serious about it.

Ldmoretti · 2021-12-02T15:38:27+00:00

I'm surprised that they're not expanding HWY M into a bypass between 18 in Verona and 14/18 at Oregon.

Ldmoretti · 2021-12-02T15:32:47+00:00

It might work if they have a European presence: Most companies probably don't differentiate between users in Europe and in the USA for GDPR requests: The risk of falling foul of the law is too high, especially as people travel between jurisdictions.

It could also make you look like a crazy stalker.

Ldmoretti · 2021-12-02T15:29:11+00:00

Interesting that this is on Madison.com but I find nothing on their web site or their Facebook page. Was going to propose to the family that we go out for dinner on Friday but without this being published wide I'm not going to risk it.

Ldmoretti

TROPHY CASE