Re: [Owfs-developers] Power Supply Question
On 21.10.18 10:20, Martin Patzak wrote: > Do you meen a switch like e.g. a DS2408? > > How do I issue an ON command with timeout? There is no off-the-shelf 1wire component that does this. You'll either have to implement it yourself using AVR or STM32 slave code, or use external components that require a regular "on" pulse (should be a no-brainer with a '555), or (my preferred solution these days) a 2-wire bus protocol like I²C that has hardware support in your controller-of-choice and thus doesn't depend on millisecond timing to work right. -- -- Matthias Urlichs signature.asc Description: OpenPGP digital signature ___ Owfs-developers mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/owfs-developers
Re: [Owfs-developers] Power Supply Question
On 10/20/18 7:00 PM, Jan Kandziora wrote: > > (I just had the problem with a remote on-off switch. Sometimes, the > **off** command is broken. Solution: always use anm on-timeout on the > device. On-commands have to be repeated each few seconds. That way, a > lost instant-off command will not do endless harm.) > > Do you meen a switch like e.g. a DS2408? How do I issue an ON command with timeout? Or is this an internal owserver thing... I don't understand. How is an OFF command differently implemented from an ON command? ___ Owfs-developers mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/owfs-developers
Re: [Owfs-developers] Power Supply Question
Am 20.10.18 um 22:01 schrieb Mick Sulley: > > You say that the DS2482-800 can reset to an unusable state, would the > same apply to the DS2482-100? Sheepwalk now make a dual channel RPi2 > and I could stack 2 to get 4 channels and I think I could manage with > that if the lock up problem is fixed. > We haven't had the same complaints from people using the DS2482-100 on this list yet. If I remember correctly. But personally, I hadn't got the lockup problem either once the power supply problems were fixed. Check your power supply. Kind regards Jan ___ Owfs-developers mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/owfs-developers
Re: [Owfs-developers] Power Supply Question
Hi Jan, Many thanks for your words of wisdom, I will take them on board. You say that the DS2482-800 can reset to an unusable state, would the same apply to the DS2482-100? Sheepwalk now make a dual channel RPi2 and I could stack 2 to get 4 channels and I think I could manage with that if the lock up problem is fixed. Thanks Mick On 20/10/2018 18:00, Jan Kandziora wrote: About the bus lock-up, that's a bug in the DS2482-800, I think. I had it. Various other people had it. The DS2482-800 seems to be susceptible to supply undervoltage and slow rising of the supply voltage. It resets into an unuseable state. Only a complete power-down and quick power-on will make it useable again. Kind regards Jan ___ Owfs-developers mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/owfs-developers
Re: [Owfs-developers] Power Supply Question
Am 20.10.18 um 18:22 schrieb Mick Sulley: > I have a Pi with Sheepwalk RPi3 adapter running multiple temperature > and I/O. I get random read failures and bus lock up, read failures > every day or two, bus lock up every week or so. > You can't to anything about spurious read and write failures. It's a bus system, they happen. You have to implement a retry on the hostn side and failsafe logic on the device side. It can be tricky. (I just had the problem with a remote on-off switch. Sometimes, the **off** command is broken. Solution: always use anm on-timeout on the device. On-commands have to be repeated each few seconds. That way, a lost instant-off command will not do endless harm.) About the bus lock-up, that's a bug in the DS2482-800, I think. I had it. Various other people had it. The DS2482-800 seems to be susceptible to supply undervoltage and slow rising of the supply voltage. It resets into an unuseable state. Only a complete power-down and quick power-on will make it useable again. Check your power supply. > Currently I have > separate power supplies (Meanwell units) for the Pi and the 1-wire > and they are both floating. > > Question - Is there an advantage in linking the 0v on the two > supplies? > You cannot have them floating. The sheepwalk adapter has a shared GND for both the Onewire and the I²C (Raspberry side). The individual ports are protected my DS9503 chips, as far as I can see it from the photos. These have 5Ω resistors in the GND lines of each connector. A good thing, do not change that. > Also should the 0v be connected to the mains earth? > Don't do that. It will give you **less** noise immunity and also fry the low voltage circuit as soon as some high voltage circuit has a ground fault. Kind regards Jan ___ Owfs-developers mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/owfs-developers
