Recommended USB Serial chip for nrf51822 custom board

[Wayne]

Hi,

We're producing a custom board based on the nrf51822 and would like to add a USB Serial chip. The current contenders are:

a) FTDI 232R b) ATmega8U2 (www.arduino.cc/.../USBSerial) c) CP2101 (www.silabs.com/.../CP2101.pdf) d) Software USB (github.com/.../LemcUSB)

Option 'a' is the classic option, but pricey (relatively speaking to our other BOM costs), but I understand it should not require any additional driver for Win, OS X or linux - a key requirement.

Option 'b' is not a preferred option as we don't want to perform the additional programming step during production. It also requires end user configuration steps, on PC's they may not have admin rights to.

Option 'c' requires driver installation, which may be an issue in some locked down OS environments, e.g. schools. (same as #2)

Option 'd' is ruled out as it would need a 24 kHz clock (or some serious code optimisations) and still carries risk.

We'd like to simplify the end user experience so any USB/Serial chips that don't require a driver install is a key requirement. Of course, the cheaper the better :)

I was wondering if anyone had used or found any other Serial USB chips for use with the nrf51822 and Win/OSX/Linux platforms?

All the best Wayne

[Jose Xavier]

You have a new ftdi chip ft230x that is cheaper.

[Nguyen Hoan Hoang]

Windows always requires installation of an .inf for CDC driver for any USB-Serial including FTDI series. May I ask what is the intended use of a USB-Serial in your project. Any interest in putting a CMSIS-DAP onboard instead ? See the IDAP-M from this page. You get both jtag & USB serial bridge.

[Wayne]

Hi, Thanks for the confirmation of the .inf situation - I wasn't really 100% sure.
It's for DFU programming and application UART data transfer in a consumer product, we have the SWD interface broken out elsewhere on our board for development/debugging. Can the chip be purchased seperately in large quantities on a reel for pick'n'place? If so how much? If you'd like to take this offline please email wayne, at, cannybots.com

[Wayne]

thanks for the heads up, I will have a look.

[MartinBL]

A quick google search shows that Mouser.com currently has 70k ++ units of FT230XS-R available in reels and tubes. It is less than half the price compared to FT232R and has better availability (at mouser.com at least). If you need more details about pricing, availability and packaging I suggest you contact the supplier directly.