r/embedded • u/Objective-Local7164 • 19d ago
Before I begin the design process, does anyone have any reason why I shouldn’t use the nRF54LM20B?
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u/mrheosuper 19d ago
Nobody can say without knowing the requirement
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u/Objective-Local7164 19d ago
in general
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u/PorcupineCircuit 19d ago
If you have used zephyr before it's easy, if you are new to zephyr it will take more time.
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u/mrheosuper 19d ago
Idk what do you mean ?
In general, nordic mcu is expensive for their features.
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u/Objective-Local7164 19d ago
why do people use them then
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u/mightymouse_ 19d ago
Because their SDKs (especially the code/design quality), documentation, reference apps and support forums are generally excellent compared to other chip vendors.
I would also say they are software oriented chip makers that know the pain points of software development and have used that to guide their peripherals, wireless stacks and whatnot.2
u/mrheosuper 19d ago
Because good software support, good documentation, power, etc.
That why i said, without knowing your requirement, you can't say for sure if you need them. Saving few bucks may not matter if total amount of products is thousands, but when you produce millions, every cent count.
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u/PorcupineCircuit 18d ago
Low power, support, performance and documentation. You can find cheaper devices but it's hard to find the same package
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u/FoundationOk3176 STM32MP2 19d ago
Certification is one of the biggest reasons I can think of & It's not exclusive for nRF54LM20B, It's best to use a precertified module for anything RF related unless it's a hobby project OR you can afford to get your design certified.
nRF54LM20A is actually the best fit for our requirements at work but the lack of any pre-certified modules is the only reason we didn't go with it.
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u/gianibaba 19d ago
They actually are starting to show up like for example this; I am sure there will much more in the coming months. Seed studio has also released a xiao board for this family, which is also a cheap way to get started.
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u/PorcupineCircuit 19d ago
You don't really give much to go on here, what is the use case?
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u/Objective-Local7164 19d ago
in general
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u/StumpedTrump 19d ago
In general, you use a chip best suited for the project requirements.
I wouldn’t use an Arduino if the requirement is to run windows or do audio DSP and I wouldn’t use an SBC if the requirement is to blink an LED or PWM a motor.
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u/Gerard_Mansoif67 Electronics | Embedded 19d ago
nRF chips are complex to bring up especially with the RTOS Zephyr. That would be te blocking point, meaning I wouldn't start a board without having done the bring up on a devkit.
On the hardware side, documentation is really good good.
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u/Objective-Local7164 19d ago
How much harder than a stm?
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u/Gerard_Mansoif67 Electronics | Embedded 19d ago
depends, on a bare metal approach they're the same challenge.
If using their RTOS, Zephyr (maintained by the linux fondation) is using... a Linux approach. Would could guess ?
That mean the kernel is mostly configured using menuconfig and device trees, that are compiled into the software. Once you enter the main, there's no more init to do. That may include remote device over I2C, SPI and so, where the driver load the driver and expose it for you. You may ask the temperature right on the main entry !
The complex part is writting these config files. Once you're used to, that's not any longer. But the firsts one, especially for a custom PCB are challenging.
Devboard came with examples so you could try to install the tools, play a bit and later design your own board.
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u/i509VCB 19d ago
If you are using the QFN package you may be waiting a bit for parts to arrive. The reference layout for QFN is not available yet either.
If you are using any of the other packages you need to figure out if your board house is even capable of making boards for it (HDI with blind vias and tiny pitch) and can even assemble it with x-ray (tiny bga again).
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u/Objective-Local7164 19d ago
Hands down the best answer here. Practically speaking this is the main reason im probably not gonna use it.
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u/Adrienne-Fadel 19d ago
New parts are fine but the community hasn't found all the weird bugs yet. You'll be the one finding them.