Hi Marko,
IMHO, The PJRC lib is a sensible basis for a Mynewt 1-Wire package since
it's seen a fair amount of real-world use, and the underlying
implementation could be configured via the syscfg.yml file (timer+GPIO
or something else like UART if you have one free)?
Kevin
On 03/07/18 12:07, marko kiiskila wrote:
Sounds like a candidate for driver interface, not HAL. I agree with Miguel.
User could pick the implementation which uses UART, or one which
uses hal_timer with hal_gpio.
However; Sam, you don’t think a generic driver interface makes sense?
If you had driver package which implemented an API similar to this:
One-Wire Library, https://www.pjrc.com/teensy/td_libs_OneWire.html
<https://www.pjrc.com/teensy/td_libs_OneWire.html>,
would you have been able to use it?
On Jul 3, 2018, at 3:11 AM, Sam Lewis <sam.vr.le...@gmail.com> wrote:
It might be more difficult to make a generic driver for but I've had some
great success using a UART peripheral to read/write 1 wire devices. There's
a good writeup of how this works in this app note:
https://www.maximintegrated.com/en/app-notes/index.mvp/id/214
The benefit is less CPU time needed for bit banging but you need to make
sure your 1 wire device fits the timing constraints of your UART peripheral.
Just thought it was worth mentioning, might be something to consider.
Sam
On Tue., 3 Jul. 2018, 6:11 am Kevin Townsend, <ke...@adafruit.com.invalid>
wrote:
Hi Miguel,
Good to hear!
Yeah, GPIO is the only way I've ever implemented this and I think a
simple SW implementation is the way to go here.
K.
On 02/07/18 21:39, Miguel Azevedo wrote:
Hi Kevin,
I actually do have some code for 1-wire I implemented a few days ago.
AFAIK most MCUs we support don't have 1-wire specific hardware, so why
not have a general implementation(using hal_timer) instead of one
implementation per MCU?
Thanks,
Miguel
On Mon, Jul 2, 2018 at 8:10 PM Kevin Townsend
<ke...@adafruit.com.invalid> wrote:
Is there any interest is discussing how to add Dallas 1-Wire support to
the HAL? https://en.wikipedia.org/wiki/1-Wire
It's a bit of a niche item, but an interesting protocol (you can power
some devices from the single GPIO line) and there are some very common
and cheap waterproof temp sensors and a few other common items that are
only available in 1 wire.
I'm happy to put one or two test drivers together for common items like
the DS18B20 (https://www.adafruit.com/product/381) ... but the HAL
implementation is something that should probably be discussed with the
wider community first.
Kevin
