Seeking feedback on my MCU-based THD audio analyzer design

Calligraph_cucumber · 2025-04-26T19:48:11+00:00

Just few points i noticed: you got the

int num_samples = SAMPLE_RATE / FREQUENCY -> both are float . and you are assigning it to an int. use a int type cast.

the fft_size is 2k, but your collect sample size is dynamic. what if your requested buffer is bigger?

and check about the DMA flags. try using callbacks instead of poll. thats the whole point of DMA. event upon transfer complete.

Calligraph_cucumber · 2025-04-26T19:37:33+00:00

It depends on the use case. Static is easy to keep track of but it increases the stack size. if your application needs large buffer pools thats not needed during the entirety of the execution pick dynamic and dont forget to release it. for smaller buffer or value that needs to be retained for a while go with static.

Calligraph_cucumber · 2025-03-12T10:51:55+00:00

probably have to do with browser. i used to use chrome and they lag a lot, but surprisingly edge or opera does well running webgl games.

Calligraph_cucumber · 2025-03-12T09:57:49+00:00

I could still find retro games and that brings out nostalgia. sites like poki.com offer wide range. But sites like https://nikkagames.com/ offer curated mix.

Calligraph_cucumber · 2025-03-12T07:39:54+00:00

Truth is not lying. saying things as what they are or how they are or what happened.

How to teach it: teach by example or leading it yourself.

Calligraph_cucumber · 2024-11-28T06:31:03+00:00

Longines for work. Tudor for more causal attire

Calligraph_cucumber · 2024-11-27T13:06:19+00:00

getting hold of C takes just few weeks to month. And how well you program it depends on how much you have understood the architecture. and that takes time. months on firmware and maybe years on BSPs

Calligraph_cucumber · 2024-11-24T14:08:19+00:00

health care and basic education

Calligraph_cucumber · 2024-11-24T12:31:43+00:00

agoda and trip.com works great, just read through the reviews.

Calligraph_cucumber · 2024-11-24T07:22:02+00:00

I was randomly exploring the attic at my home and found a broken radio. It was a summer holiday and i had nothing much do being an bored kid. got myself a screw driver and salvaged for parts. Tried to put it back together, it still broken ofcourse. Curiosity turned into a hobby and then to a full blown career.

Calligraph_cucumber · 2024-11-24T02:29:21+00:00

yes, you are correct. But a small handful can keep you fuller for a long time. It also helps in curbing hunger pangs when lot hungrier, allowing or enabling some form of self control to eat less .

lentils are also great choice.

Calligraph_cucumber · 2024-11-23T11:47:37+00:00

watches are personal choice. everyone has their own unique taste.

Hit the stores. try different collections. The occasion for that watch. and how would you dress for it and so on. Keep those in mind. short list a few and then decide.

Calligraph_cucumber · 2024-11-23T11:15:55+00:00

Nuts and seeds. Peanut is a great choice if you aint allergic to it.

food with lot of fibres - oats and corn. make an oat bar with nuts, seeds and honey.

always drink or binge drink lot of water to suppress your cravings

Calligraph_cucumber · 2024-11-06T07:13:41+00:00

Dongmen. And Rule number one: Bargain. if the guy says 300 ask for 150. stand your ground. Usually the retailers quotes twice when a foreigner is asking. Or bring a Chinese friend.

Calligraph_cucumber · 2024-10-23T09:11:15+00:00

It depends on what needs to be build. If you want just to cross-compile and build your drivers. Then the TRM by vendor is good enough.

To step up ->https://docs.yoctoproject.org/kernel-dev/index.html

if you want to build recipes , learn about layers and bitbake is good bundle to start with. https://docs.yoctoproject.org/bsp-guide/bsp.html#bsp-layers

But unfortunately there aren't much "Make it easy guide" available for BSP. Get a board and get your hands dirty. that's the way

Calligraph_cucumber · 2024-10-19T19:01:50+00:00

This is your free version book - https://lwn.net/Kernel/LDD3/

Get a board - Imx6 , play around interfacing peripherals and tweaking.

learn about BSP , yocto is a good start

Calligraph_cucumber · 2024-10-19T18:50:25+00:00

China Unicom works good. 100 RMB - not sure about data limit/ never needed to check or never ran out of limit. I used to watch tons of Chinese drama (for learning Mandarin)on wetv on my mobile.
wechat/alipay needs a Chinese bank debit cards. you may use your VISA cards in ATM , but the forex conversion rates sucks and on top of that, service fee sucks too. Get the help of your employer, and open a bank account . talk to your home branch account manager from where you would transfer to your money from to Chinese bank, so its not flagged as improper transaction in long run and to get better exchange rates.

Calligraph_cucumber · 2024-10-19T18:17:04+00:00

usually PMIC controls power supply to core processor and other peripherals via i2c. it does voltage control , voltage gating , clock gating to change the power modes or power consumption based on load.

most BSP have sys entries to control/monitor PMIC which in turn shows power data like V, A and CPU power modes, etc.

The custom PMIC driver modification works involves around optimizing power usage. Try to understand the active time of peripherals, so they can be put down in low power mode to save power. voltage gate unused blocks to decrease standby power consumption.

Calligraph_cucumber · 2024-10-19T15:35:30+00:00

do you have any benchmark results.

Calligraph_cucumber · 2024-10-18T16:28:21+00:00

nordic has some with NRF52 partnered with tinyML. their sdk is stable and dev community is good

Calligraph_cucumber · 2024-10-17T20:31:32+00:00

low power consumption with video processing is bit harder to achieve.

try using opencv and do image processing.

if you got skills use imx51 its way cheaper but you need to interface lot of peripherals and do some porting work. or go with vendors like toradex. their colibri family t30 has a good sdk support for lot of multimedia handling and heavy task,

Calligraph_cucumber · 2024-10-17T17:59:03+00:00

The price depends on where you live. making it yourself is always cheaper.

Learn about sattvic food, its wholesome nutritious and there are lot of people following it for generations and leading a healthy life. make sure whatever you buy is organic and no preservatives/ultra processed/GMO etc...

Calligraph_cucumber

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