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Maximum Number of Zones
#47
(2021 Jun 22, 10:10 PM)astrogerard Wrote: Great to see you are almost there!

The power your Pi can deliver on 5v depends on the power usage of the Pi itself and the psu you have connected to it. Also USB devices, if any, will consume from the 5V power.  If the Pi is not doing some heavy stuff there is likely to be enough power to drive all inputs at the same time.
Assuming you have 4 relay boards of 8 channels, that makes 32 * 20mA = 640mA. I think the 20mA is in reality a bit lower.

So I'm fairly sure that if your Pi is running SIP only and you have no USB devices connected you can drive all channels at the same time. There are however fuses on the Pi which eventually can blow when overloaded.  If you are really in to pushing the limits I can do some more precise calculations/estimations.

--Gerard

Using a PWR+ charger, mfg states 5v 2A 2.5A 3A 3.5A but no way to verify. In case I run into problems can you recommend a robust power supply?

USB wifi adaptor uses 340 mA when TX and 160 mA when RX.

Breadboard w/ 4 shift registers attached.

Running the Pi OS Desktop Headless, SIP, APCUPSD (maybe that will tell me what the Pi is drawing), no keyboard or mouse attached.

So I guess I am ready to move on to connecting the irrigation valves to the relays and the third power supply.

Thank you again.
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Messages In This Thread
Maximum Number of Zones - by HereComesTheRain - 2020 May 28, 03:01 PM
RE: Maximum Number of Zones - by dan - 2020 May 28, 03:14 PM
RE: Maximum Number of Zones - by HereComesTheRain - 2020 May 28, 03:43 PM
RE: Maximum Number of Zones - by dan - 2020 May 28, 05:40 PM
RE: Maximum Number of Zones - by HereComesTheRain - 2020 May 28, 07:14 PM
RE: Maximum Number of Zones - by dan - 2020 May 28, 08:07 PM
RE: Maximum Number of Zones - by astrogerard - 2020 May 29, 04:16 PM
RE: Maximum Number of Zones - by HereComesTheRain - 2020 May 29, 07:45 PM
RE: Maximum Number of Zones - by HereComesTheRain - 2020 May 29, 09:42 PM
RE: Maximum Number of Zones - by astrogerard - 2020 Jun 04, 04:08 PM
RE: Maximum Number of Zones - by HereComesTheRain - 2020 Jun 09, 04:38 PM
RE: Maximum Number of Zones - by astrogerard - 2020 Jun 09, 06:18 PM
RE: Maximum Number of Zones - by HereComesTheRain - 2020 Jun 09, 08:03 PM
RE: Maximum Number of Zones - by dan - 2020 Jun 09, 09:46 PM
RE: Maximum Number of Zones - by HereComesTheRain - 2020 Jun 09, 10:55 PM
RE: Maximum Number of Zones - by dan - 2020 May 30, 03:42 PM
RE: Maximum Number of Zones - by HereComesTheRain - 2021 May 24, 01:10 AM
RE: Maximum Number of Zones - by dan - 2021 May 25, 04:00 PM
RE: Maximum Number of Zones - by HereComesTheRain - 2021 May 25, 05:41 PM
RE: Maximum Number of Zones - by dan - 2021 May 26, 02:08 PM
RE: Maximum Number of Zones - by HereComesTheRain - 2021 May 26, 04:02 PM
RE: Maximum Number of Zones - by dan - 2021 May 27, 12:13 AM
RE: Maximum Number of Zones - by HereComesTheRain - 2021 Jun 06, 01:08 AM
RE: Maximum Number of Zones - by dan - 2021 Jun 06, 02:23 PM
RE: Maximum Number of Zones - by HereComesTheRain - 2021 Jun 06, 04:28 PM
RE: Maximum Number of Zones - by dan - 2021 Jun 06, 04:52 PM
RE: Maximum Number of Zones - by HereComesTheRain - 2021 Jun 06, 10:09 PM
RE: Maximum Number of Zones - by dan - 2021 Jun 13, 01:53 PM
RE: Maximum Number of Zones - by HereComesTheRain - 2021 Jun 13, 07:59 PM
RE: Maximum Number of Zones - by dan - 2021 Jun 14, 01:11 PM
RE: Maximum Number of Zones - by HereComesTheRain - 2021 Jun 18, 11:43 AM
RE: Maximum Number of Zones - by dan - 2021 Jun 18, 02:27 PM
RE: Maximum Number of Zones - by HereComesTheRain - 2021 Jun 18, 02:47 PM
RE: Maximum Number of Zones - by HereComesTheRain - 2021 Jun 18, 03:51 PM
RE: Maximum Number of Zones - by HereComesTheRain - 2021 Jun 18, 08:36 PM
RE: Maximum Number of Zones - by dan - 2021 Jun 19, 01:20 PM
RE: Maximum Number of Zones - by HereComesTheRain - 2021 Jun 20, 01:54 AM
RE: Maximum Number of Zones - by HereComesTheRain - 2021 Jun 22, 02:18 PM
RE: Maximum Number of Zones - by astrogerard - 2021 Jun 22, 03:40 PM
RE: Maximum Number of Zones - by HereComesTheRain - 2021 Jun 22, 04:56 PM
RE: Maximum Number of Zones - by astrogerard - 2021 Jun 22, 06:30 PM
RE: Maximum Number of Zones - by astrogerard - 2021 Jun 22, 07:49 PM
RE: Maximum Number of Zones - by HereComesTheRain - 2021 Jun 22, 08:34 PM
RE: Maximum Number of Zones - by astrogerard - 2021 Jun 22, 08:45 PM
RE: Maximum Number of Zones - by HereComesTheRain - 2021 Jun 22, 09:40 PM
RE: Maximum Number of Zones - by astrogerard - 2021 Jun 22, 10:10 PM
RE: Maximum Number of Zones - by HereComesTheRain - 2021 Jun 22, 11:48 PM
RE: Maximum Number of Zones - by astrogerard - 2021 Jun 23, 07:31 AM
RE: Maximum Number of Zones - by HereComesTheRain - 2021 Jun 24, 12:07 AM
RE: Maximum Number of Zones - by astrogerard - 2021 Jun 24, 06:55 AM
RE: Maximum Number of Zones - by HereComesTheRain - 2021 Jun 24, 12:51 PM
RE: Maximum Number of Zones - by astrogerard - 2021 Jun 24, 06:24 PM
RE: Maximum Number of Zones - by HereComesTheRain - 2021 Jun 24, 09:01 PM
RE: Maximum Number of Zones - by astrogerard - 2021 Jun 24, 09:58 PM
RE: Maximum Number of Zones - by HereComesTheRain - 2021 Jun 24, 11:47 PM
RE: Maximum Number of Zones - by astrogerard - 2021 Jun 25, 09:49 AM
RE: Maximum Number of Zones - by HereComesTheRain - 2021 Jun 25, 12:37 PM
RE: Maximum Number of Zones - by astrogerard - 2021 Jun 25, 01:13 PM
RE: Maximum Number of Zones - by dan - 2021 Jun 25, 01:26 PM
RE: Maximum Number of Zones - by astrogerard - 2021 Jun 25, 04:27 PM
RE: Maximum Number of Zones - by HereComesTheRain - 2021 Jun 25, 06:57 PM
RE: Maximum Number of Zones - by astrogerard - 2021 Jun 25, 07:57 PM
RE: Maximum Number of Zones - by HereComesTheRain - 2021 Jun 27, 01:19 PM
RE: Maximum Number of Zones - by dan - 2021 Jun 27, 03:12 PM
RE: Maximum Number of Zones - by HereComesTheRain - 2021 Jun 27, 03:54 PM
RE: Maximum Number of Zones - by dan - 2021 Jun 27, 04:43 PM
RE: Maximum Number of Zones - by HereComesTheRain - 2021 Jun 27, 05:02 PM
RE: Maximum Number of Zones - by dan - 2021 Jun 27, 06:21 PM
RE: Maximum Number of Zones - by HereComesTheRain - 2021 Jun 27, 07:25 PM
RE: Maximum Number of Zones - by astrogerard - 2021 Jun 28, 12:22 PM
RE: Maximum Number of Zones - by HereComesTheRain - 2021 Jun 28, 04:56 PM
RE: Maximum Number of Zones - by astrogerard - 2021 Jun 28, 06:05 PM
RE: Maximum Number of Zones - by HereComesTheRain - 2021 Jun 28, 07:59 PM
RE: Maximum Number of Zones - by astrogerard - 2021 Jun 29, 12:09 PM
RE: Maximum Number of Zones - by HereComesTheRain - 2021 Jun 29, 03:02 PM
RE: Maximum Number of Zones - by astrogerard - 2021 Jun 29, 07:59 PM
RE: Maximum Number of Zones - by HereComesTheRain - 2021 Jun 29, 10:39 PM
RE: Maximum Number of Zones - by astrogerard - 2021 Jul 08, 09:24 PM
RE: Maximum Number of Zones - by HereComesTheRain - 2021 Jul 08, 09:50 PM
RE: Maximum Number of Zones - by astrogerard - 2021 Jul 09, 08:54 PM
RE: Maximum Number of Zones - by HereComesTheRain - 2021 Jul 11, 02:11 AM
RE: Maximum Number of Zones - by astrogerard - 2021 Jul 11, 06:47 PM
RE: Maximum Number of Zones - by astrogerard - 2021 Jul 29, 07:54 PM

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