I have bought already a couple of DS3231 at aliexpress, battery included and they cost around 1USD
On 23 July 2017 at 07:50, Rupert Gallagher <r...@protonmail.com> wrote: > Dirty cheap. > https://www.adafruit.com/product/3013 > Sent from ProtonMail Mobile > > On Sat, Jul 22, 2017 at 8:33 PM, gwes <g...@oat.com> wrote: > > > On 07/22/17 12:10, Theo de Raadt wrote: > > I'd really like if someone > could find a USB RTC clock, which is a viable > affordable product which we > can then create good support for. I've searched > and found a few > prototypes and 'licence key' products, but nothing readily > available > which we could support & encourage as a solution for the RTC > problem. > > What kind of packaging, fit & finish, and price would be acceptable? For > example: A commodity microcontroller on a tiny PCB, a Dallas Semi RTC on > another tiny commodity PCB and a lithium coin cell in a 4cm x 6cm x 2cm > commodity box could be professionally assembled and sold in unit quantities > in a month for $50. Accuracy limit is the 32Khz crystal. Temperature > compensation to match the standard quartz curves in the ucode. Burn-in and > trimming to a few PPM would add maybe $5. The same parts on a single PCB in > a slightly smaller box might take three months, an expected sale quantity > of 50, and sell for $30. USB stick size, etc. - I'm sure you can > extrapolate from there. Geoff Steckel > -- Regards, -- Rui Ribeiro Senior Linux Architect and Network Administrator ISCTE-IUL https://www.linkedin.com/pub/rui-ribeiro/16/ab8/434
