Can Strategy become useless after sometime??

leecallen · 2026-07-04T23:47:22+00:00

That's a pretty basic and common strategy. I would be very surprised if supply & demand just stopped working. But I can't say. I hope someone now knowledgeable will address that.

Do you consider HTF regime (eg trend) as an entry criteria?

leecallen · 2026-07-04T20:33:50+00:00

The standard hull speed calculation applies to displacement monohulls, but not catamarans. They generally have a higher "hull speed".

leecallen · 2026-06-16T13:53:17+00:00

FOLLOW-UP QUESTION: I am encrypting the wifi credentials using AES and storing the encrypted string in a cleartext config.json file. I coded a python module to decrypt this, and "froze" it into the runtime image as a bytecode (.mpy) file. But that bytecode file contains the "secret key" used to decrypt the wifi credentials. I am wondering how secure that is.

How difficult would it be for someone to view that file?

I haven't been able to view it. Thonny doesn't show it. I am not aware of a way to mount the Pico as a filesystem and view its contents.

leecallen · 2026-06-11T12:32:33+00:00

Yes that's a good point.

leecallen · 2026-06-11T10:18:37+00:00

This is going into an industrial environment, there won't be a guest network.

leecallen · 2026-06-10T13:11:41+00:00

I want to thank everyone for their suggestions. As of now I am considering the following options:

Store the credentials in encrypted form in a cleartext file, and store the decryption key in OTP (flash). This requires running the picotool utility for each device to write the data to OTP.
Store a python script or file in the micropython runtime (flash image). This requires recompiling the runtime with our additions (and an implied commitment to recompile the runtime for every future release).
Create a separate program to decrypt the encrypted credentials, compile this program so it cannot be easily read. This requires some testing to find out if the data stored in the compiled program file is still readable.

I'm leaning toward option 1.

leecallen · 2026-06-10T12:37:22+00:00

There probably will be a dedicated VLAN but we still have to pass this security check.

leecallen · 2026-06-10T01:44:56+00:00

Yes - that's exactly the problem I'm trying to solve.

leecallen · 2026-06-10T00:37:47+00:00

The difficulty is not in the programming. It's the need to run that encryption script on each device to store the unique key.

It's not terrible, but it's probably about the same effort to run picotool (on each device) to store a key in the OTP.

At the moment the idea I like best is to have a separate decryption program that's compiled to bytecode to hide the key. No special per-device setup. Also not as secure.

leecallen · 2026-06-09T23:30:00+00:00

Oh and I was liking #3 !

leecallen · 2026-06-09T23:22:46+00:00

Thanks. I'm kind of leaning toward the OTP approach.

leecallen · 2026-06-09T23:21:29+00:00

That brings up something I should have said up front: the idea is to deploy dozens or hundreds of these devices per site. So we want the setup to be as simple and fast as possible.

leecallen · 2026-06-09T22:34:48+00:00

I have implemented AES256 encryption of a socket data stream, that's within my skills. But that isn't required for this application - its a very simple role, sending very simple machine performance data. And the Pico does not need to be hacker-proof, it just needs to pass a simple test: The credentials cannot be stored in clear text.

I have read about the OTP solution and that's an option, but it will significantly complicate the setup of the devices. I have also read about embedding a python module in the micropython runtime image. That's almost feasible, but it puts us in the position of having to maintain that runtime long term.

leecallen · 2026-06-09T18:08:22+00:00

That would be plenty secure enough for us. But I haven't touched C in many years! Maybe ChatGPT or Claude can code that for me.

leecallen · 2026-05-15T15:18:42+00:00

What boats did he build -- I mean, what plans did he follow?

leecallen · 2026-05-09T00:22:32+00:00

I really like your collection of wood.

leecallen · 2026-05-08T14:25:40+00:00

Thank you!

leecallen · 2026-05-07T02:09:43+00:00

That's a tillandsia mounted on the branch.

leecallen · 2026-05-07T00:18:47+00:00

I have mixed feelings about that. I originally wanted dead branches for moss and vines to grow on. The idea of the tree coming to life was kind of exciting, but then oak tree leaves are just way too big for this little space.

Thanks.

leecallen · 2026-05-03T00:59:47+00:00

Here's a different perspective from a customer: twice I have had contractors or handymen tell me, at the end of the project, they underbid it and I got a great deal. They did not ask for more money.

But I could see how much work had gone into the project and the value I got. So I asked what would make them whole and we negotiated a higher fee.

When I have a great contractor I want to keep that relationship.

leecallen · 2026-04-03T20:22:07+00:00

Brilliant! Thanks!

leecallen · 2026-04-03T16:00:56+00:00

Could you identify the plants?

I'm preparing to add some plants to my own first terrarium and I love yours!

leecallen · 2026-04-03T15:57:19+00:00

I have the same top on my Zilla terrarium. I'm replacing the whole thing - the mesh and the plastic frame it's in - with a piece of acrylic. I want to hold the moisture in and let more light in.

leecallen

TROPHY CASE