I have seen this question asked before but it was over 8 years ago and I assume things must have changed since then. Basically, I am working on a personal project that I would like to see if I can sell, I made a wearable prototype using an Arduino Nano 33 BLE , all it does is send accelerometer/gyroscope data over bluetooth to an iOS Application I made. I can't use the Arduino in a commercial project and I need something more compact to fit in a wearable enclosure. My question is, is my next step to replace the Arduino with a custom made PCB or are there other options out there now such as pre built boards that can satisfy my BLE, Accel/Gyro , and Small Size requirements? I couldn't find much information besides building a PCB. I would like to keep the overhead as low as possible so if custom PCB is the route then I would be designing the PCB myself (I have never done this before but I can learn) and sending the files to get manufactured. Any insight on the route I should take going forward would be greatly appreciated. Thank You.
The route to go will probably be to design a custom pcb, it is almost certainly the most cost effective option. If you go down this route you will very likely need someone with experience in hardware design because there is very many things to consider here if you want to do it properly, especially since it is probably going to be a low power application?
Bare in mind also that true professional embedded programming (like stm32wb, nrf52, BGM or other Bluetooth MCUs) is nothing like programming an Arduino, so even this will be a project of its own with which you will probably have your hands full for months.