Recommend an SoC for someone who's a little rusty - Page 1
Forum section: electronics / projects

author: TriStateSearcher
author_rank: Newbie
timestamp: July 18, 2022, 03:53:35 pm
content: Hi there! Lurker for ages, finally have a query for the group.I'm starting a new project and... many years out-of-date on the state of SoCs out there. Looking for any and all suggestions on a BoM.The project overall will have the following minimum requirements:Gyro and accelerator - need to activate upon motion & recognize/transmit certain movementsBluetooth LE radio - as above; chip antenna (minimum "certification stuff" on my end) preferredLow power envelope overall / good power management features - need to power by coin cellAvailable in ~low volumes - hobbyist project on the order of 100~1000 units/yearNice-to-haves that would be in addition:Wifi radio - if available in addition to BTLEDecent toolchain - all things being equal, would rather use something from a vendor that makes/supports good tools (linux/mac compatibility ideal; good frameworks a plus)Integrated gyro and accelerometer - am assuming a second part is best, but if it's all available in one package, that probably makes my assembly easierYour thoughts? Anything spring to mind for the SoC (if not the gyro/accelerator as well)? Thanks in advance!

author: tooki
author_rank: Super Contributor
timestamp: July 18, 2022, 05:24:22 pm
content: Bearing in mind that availability is a huge problem with so many MCUs at the moment, I’d take a look at the ESP32 series. They all have Wi-Fi, and most have Bluetooth, too. Models with BT LE 5 are available. Key phrase: they’re actually available!I have no experience with their native framework (ESP-IDF), but they’re well supported by the Arduino framework, where it’s one of the most popular MCUs. (I know you can also call the ESP-IDF from within Arduino sketches, though I’ve never done it.)My impression is that the toolchain that’s most popular for these for halfway advanced users is using them with the Arduino framework with PlatformIO under Visual Studio Code. I switched to this (from Arduino’s own IDE) earlier this year and haven’t looked back. (It’s on Win/Mac/Linux.)The only real gripe I have about that setup is that the hardware debugger is hit or miss: it works fine most of the time, but in some programs, it just won’t connect. It’s only $10, so it doesn’t hurt the budget, but I wish it were more reliable.Without using power management features, they’re definitely not the lowest power. But it’s my understanding that with power management, it can be dramatically reduced. IIRC, the most granular power management control is available in ESP-IDF.

author: TriStateSearcher
author_rank: Newbie
timestamp: July 18, 2022, 09:57:41 pm
content: Thanks for the thoughts! Have had a good experience tinkering with some ESP32 devices, especially on the toolchain side.

author: rooppoorali
author_rank: Regular Contributor
timestamp: July 23, 2022, 11:43:38 am
content: You can also take a look at Adafruit Feather 32u4 Bluefruit LE:https://www.adafruit.com/product/3379

author: tooki
author_rank: Super Contributor
timestamp: July 23, 2022, 01:02:46 pm
content: What advantage does it have over an ESP32, given that it’s triple the cost and has vastly lower computing power (and no WiFi)?

author: Buriedcode
author_rank: Super Contributor
timestamp: July 23, 2022, 06:51:05 pm
content: I don't think you can get WiFi functionality powered form a coin cell, its a pretty power hungry standard (as is vanilla bluetooth, which is why we have BTLE now).Although I haven't seen any boards with a Gyro and accelerator on board, nordics offerings are pretty good as far as BTLE modules go - designed for low power, and have powerful processor cores M4F (for heavy lifting, but unless you're doing DSP you probably won't need one).That Adafruit board rooppoorali linked has a nrf51822 module on board (https://www.nordicsemi.com/products/nrf51822) which has an M0 core. I'm unsure why they've bolted on an ATMEGA there, perhaps its just for its USB interface to make developing/prototyping/debugging easier. Sound like you could just get away with the nordic chip for the final design - the module are handy as they're certified, and handle all the RF stuff. Sounds ideal to develop on.I'm sure ESP32 could be worked to use low power, as many modern devices have all manner of sleep/idles modes to reduce average power consumption, and its quite easer to get a development enviroment up and running, but I don't see it being lower power than the nordic devices (which btw are pretty common in air tags and smart watches, all things BTLE).