It (the DS3231) is on the I2C bus. Is that good or bad?
On 2017-07-23 06:50, Rupert Gallagher wrote:
Dirty cheap.
https://www.adafruit.com/product/3013
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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
