On 6/04/2018 11:11, Eric S. Raymond wrote:
Phil Reid <preid@xxxxxxxxxxxxxxxxx>:
You should probably be using the sbs-battery driver for interfacing to the chip.
I was not aware there is already a dedicated driver. That will simplify my task a lot.
I believe those message are only relevant to a sbs charger.
The one I'm really concerned about is the remaining-capacity alarm. That, of cource,
may be presented even if there's an inboard charger. Is there by any chance an alarm
node in syfs that a read will block on until one of these alarms is raised? I'm
writing in Go, so using that would be trivial exercise.
(I'd RTFM, but searches are not revealing any...)
Do you have a sbs compliant charger interfacing to this device?
I don't have a physical device at all yet. I'm *expecting* to
interface to a smart battery supporting an inboard charger, with a
four-wire interface consisting of DC in/out and an SMBUS pair.
The backstory is some friends and I are attempting to design an
open-source/open-hardware UPS because we're deeply unhappy with what
the incumbent vendors are pushing. We already have a logical design for the
high-power plane; it comes down to the one BMS interface, five sensors,
and four relays or triacs. The EE on our team is starting on a
breadboard implementation now.
Presently I'm writing code that can mock all those BMS and sensor
readings from a synthetic logfile so I can verify the control software
that I''ll write next. The goal is to have the transaction logic all
tested when the breadboard version is complete.
We don't actually have a target battery chosen yet. We're looking for
one that can carry a 300W load for 15 minutes, has an inboard
charger, supports SBS-1.1 and is *not* lithium-ion, because explosion
hazards suck.
We've had our eye on LiFePO but haven't found a COTS battery pack with
all these features together. Suggestions welcomed.
Not looked at the device to closely. But I think you'll need a i2c controller running as a slave
to listen to those broadcast alarm messages.
Switch modes is possible on some i2c host controllers / some not.
Unless it uses something like SMBus Host notify protocol which some controllers support.
Which I couldn't see a mention of.
Otherwise your back to polling. Which would be more compliant with a wider range of SBS compliant batteries.
Have a look at the ltc1760 for a charger depending on you battery voltage.
If you do want COTS LiION then look at Inspired Energy, they have some stuff that'd meet
your electrical specs.
They can do custom stuff as well.
I'm just a happy customer.
--
Regards
Phil Reid
