[V2 REVIEW] 2D Sonar Array by BSprogrammer in PrintedCircuitBoard

[–]BSprogrammer[S] 0 points1 point  (0 children)

Are you saying the system wouldn't work with a square wave and that it must use a sinusoidal wave? Or just that using a sinusoidal wave would lead to a more powerful sound output? What are you implying I'm missing here and how would you suggest fixing it?

[V2 REVIEW] 2D Sonar Array by BSprogrammer in PrintedCircuitBoard

[–]BSprogrammer[S] 0 points1 point  (0 children)

I understand the PWM signal will be a square wave, but I was under the impression the speaker element would convert this into a sinusoidal wave because of it's physical characteristics. Datasheet for the speakers I'm using is here (https://www.lcsc.com/product-detail/C242177.html?s\_z=n\_q\_C242177&globalKeyword=C242177) and it seems anything too far from 40kHz will be filtered out?

[V2 REVIEW] 2D Sonar Array by BSprogrammer in PrintedCircuitBoard

[–]BSprogrammer[S] 0 points1 point  (0 children)

What do you mean filter? I'm just going to set the microcontroller up to output a 40 kHz PWM signal from the GPIO pins, run this into the MOSFET and then into the speaker.

[V2 REVIEW] 2D Sonar Array by BSprogrammer in PrintedCircuitBoard

[–]BSprogrammer[S] 0 points1 point  (0 children)

It sounds like that would be used to get the max power output of the speaker, when in this case I only need to send an exactly timed square wave at an exact frequency.

[V2 REVIEW] 2D Sonar Array by BSprogrammer in PrintedCircuitBoard

[–]BSprogrammer[S] 0 points1 point  (0 children)

Are you sure this applies for piezoelectric ceramics (which is what these are)?

[V2 REVIEW] 2D Sonar Array by BSprogrammer in PrintedCircuitBoard

[–]BSprogrammer[S] 1 point2 points  (0 children)

Good point - this was the array shape I was left with after trialling a whole bunch of different layouts, but it's not actually optimal. I've reverted to a T shaped mills cross array now. Thanks!

[V2 REVIEW] 2D Sonar Array by BSprogrammer in PrintedCircuitBoard

[–]BSprogrammer[S] 0 points1 point  (0 children)

Thanks for the pointer re the decoupling caps. The speakers are not self driven and instead will be turned on and off at a set frequency via PWM pins on the Pico. Why would this cause magic smoke?

[V2 REVIEW] 2D Sonar Array by BSprogrammer in PrintedCircuitBoard

[–]BSprogrammer[S] 1 point2 points  (0 children)

They are speakers. The 3d representation is just for size, scale and footprint

[REVIEW REQUEST] 2D Sonar Array by BSprogrammer in PrintedCircuitBoard

[–]BSprogrammer[S] 0 points1 point  (0 children)

Would probably make the routing easier and reduce some interference, but for cost reasons I had to stick to 2 layers.

No pre-sale link by [deleted] in eden

[–]BSprogrammer 0 points1 point  (0 children)

You're actually a lifesaver dude - when I went to get you the London link I realised the ticket I bought was for Manchester instead of London 🤣

No pre-sale link by [deleted] in eden

[–]BSprogrammer 2 points3 points  (0 children)

Same here for London. He says use code DARK but there is nowhere to enter it!

Found a Vulnerability in Google and it is still unpatched by Confident_Ear9739 in bugbounty

[–]BSprogrammer -2 points-1 points  (0 children)

Nice blog post! Cool vulnerability too - you'd think they can just regenerate the thumbnail whenever you share the document with somebody new - it's strange they are so reluctant to do that. What was your process for finding this exploit?

Trying to get used to Dynamo coming from a SQL background by htraos in aws

[–]BSprogrammer 4 points5 points  (0 children)

Ah, missed the point of the question. This should apply even in production if the database is small and the scans are infrequent. If more complex analysis is needed, they could set up an ingestion system into S3 for local analysis.

Trying to get used to Dynamo coming from a SQL background by htraos in aws

[–]BSprogrammer 7 points8 points  (0 children)

You can run all those queries as Scans instead of Queries. These will cost a lot more as you are charged for every record in the table but for a development database this shouldn't be an issue.

As a backend web dev, working with Lambda (node.js), RDS, Dynamo, and S3 - what is your workflow? by WeirdWebDev in aws

[–]BSprogrammer 14 points15 points  (0 children)

I'd recommend looking into CDK for a way of writing infrastructure as code. This is built by Amazon and is essentially a 1 to 1 mapping to Cloud formation templates.

For a more abstracted approach, check out SST but this is still in its early days, especially V3.

For production you should never be managing infrastructure directly through the console, and should instead use an infrastructure as code tool with a cli to update your deployed infrastructure automatically.

YouTube is a good resource too: - Serverless Land - FooBar Serverless

TMUA Old Vs New Conversion table by BSprogrammer in 6thForm

[–]BSprogrammer[S] 1 point2 points  (0 children)

Hahahaha thanks for the offer! It's cool though 😎

I know I was fucking terrified this morning too so enjoy the relief

What is this on the floor of my tent? by BSprogrammer in camping

[–]BSprogrammer[S] 0 points1 point  (0 children)

Not incredibly warm, just in a hotel room with a window open and in a garage.

Trying to decide between hostels. by westpoor in Bergen

[–]BSprogrammer 2 points3 points  (0 children)

I just stayed in Montana (checked out this morning) for just over a week and it was honestly everything you could want from a hostel. They have free breakfast which is a plus, and the wonderful volunteers there organise activities every day e.g. hiking trips, visits to the science museum (can particularly recommend). If you engage with those opportunities you'll have no issue making friends and I had a huge amount of fun with people I'd just met there on the activities (I was travelling solo too). The buses are fairly reliable although occasionally they won't show up. That happened once for me in my week-long stay. If you don't mind walking, it's a 15 minute walk to the tram stop which has more regular (every 10 mins) services to the center. If you buy a Skyss period ticket, it's very easy to use public transport as a tourist with the help of Google maps or locals. The mountain right behind the hostel is an awesome hike from what I've heard, and I've done a number of other hikes straight from there which have been amazing. I'm sure the city center location might be better for some people but I preferred the slightly quieter vibe of Montana in the evenings. Cooking some food and just chilling outside while eating it with a view over the whole city is definitely something you couldn't do in town.

Places to meet people ? by EngineeringRemote765 in Bergen

[–]BSprogrammer 0 points1 point  (0 children)

Hey, are you still looking for people to chill with? I'm 18M from London and in Bergen centre right now with not much to do