OpenSprinkler Forums Hardware Questions OpenSprinkler Pi (OSPi) Raspberry Pi OSPi Model Guide

Viewing 11 posts - 1 through 11 (of 11 total)
  • Author
    Posts
  • #67548

    jptaranto
    Participant

    Mods: something got messed up with my first topic post, so I’m posting this again. Please delete the first post if it shows up for you.

    I’d love to make this a complete guide post about which Raspberry Pi models are ideal to use with the OSPi board. But I’m still pretty unclear about the pros/cons. Here’s what I’ve got so far:

    RPi 1 Model A
    Enclosure not compatible
    Powered by OSPi AC transformer
    No WiFi

    RPi 1 Model B
    Enclosure not compatible
    Powered by OSPi AC transformer
    No WiFi

    RPi 1 Model A+
    Enclosure not compatible??
    Powered by OSPi AC transformer
    No WiFi

    RPi 1 Model B+
    Powered by OSPi AC transformer
    No WiFi

    RPi 2 Model B
    Powered by OSPi AC transformer
    No WiFi

    RPi 2 Model B 1.2
    Powered by OSPi AC transformer
    No WiFi
    64-bit

    RPi 3 Model B
    Needs separate DC power supply
    2.4 GHz WiFi
    64-bit

    RPi 3 Model A+
    Enclosure not compatible??
    Needs separate DC power supply
    2.4/5 GHz WiFi
    64-bit

    RPi 3 Model B+
    Needs separate DC power supply
    2.4/5 GHz WiFi
    64-bit

    RPi 4 Model B
    Needs separate DC power supply
    2.4/5 GHz WiFi
    64-bit

    RPi Zero PCB v1.2
    Powered by OSPi AC transformer
    No WiFi
    No GPIO header (needs to be soldered on)

    RPi Zero PCB v1.3
    Powered by OSPi AC transformer
    No WiFi
    No GPIO header (needs to be soldered on)

    RPi Zero W
    Powered by OSPi AC transformer
    2.4 GHz WiFi
    No GPIO header (needs to be soldered on)

    I’d love some input on which model Pis are being used and any pros/cons that you’ve come across.

    There are so many Pi models and specs vary widely, and with cost increases due to COVID it could even be wise to use a 1 or 2 B model.

    Raspberry Pi spec sheets: https://en.wikipedia.org/wiki/Raspberry_Pi#Specifications

    #67550

    Ray
    Keymaster

    Thanks for the list. My understanding is that RPi 1 Model A or B (which has 2×13 pins) has long been discontinued, I am not sure where to buy them actually. All other RPis use 2×20 pin header, and should fit in the current enclosure. This includes RPi 1 model A+, which also uses 2×20 pin header.

    Also we have started shipping OSPi version 1.5 since a few weeks ago. Version 1.5 uses an improved switching regulator and can provide up to 2amp current on +5V line so should be able to drive all RPis without needing external USB power supply.

    Though, technically, to really deliver 2amp it would draw quite a lot of current from the input 24VAC adapter as well. For example, to deliver 2amp @ 5V and assuming 70% efficiency of switching regulator, it will need to draw about 600mA from the input 24VAC, which is a significant amount.

    #67566

    jptaranto
    Participant

    Oh that’s great news Ray! Cheers for that. I just bought a couple of OSPi boards last week, so I’m really looking forward to getting them setup. I’m yet to buy the RPis, however I went ahead and bought a couple of 24vac 1.87amp transformers. So they should do the job of powering the RPi (if I go with a 3 or 4) and a number of valves simultaneously.

    #67567

    jptaranto
    Participant

    Looks like there’s a redirect issue when I try to edit the original post.

    #67591

    psmedley
    Participant

    I’m using a Pi Zero here – I can’t remember if I soldered the header myself or ordered one with the header on it already.

    #67648

    jptaranto
    Participant

    I ended up going with a RPi 1 A+. I’ll be using a USB wifi adapter with an antenna. Hoping it’s got enough power via it’s usb port to work from 50m away from the external AP.

    #68258

    JimS
    Participant

    Don’t know where you are seeing cost increases in the pi due to covid. The local microcenter still has a number of models up to the 3s for about $35 and many under $30. Seems the same as it always was.

    #68294

    Leesburg_Dave
    Participant

    I’m using an RPI0W. Soldered a header on for the GPIO. This is my second one. We had a lightning strike on a neighbor’s tree across the street that took out one of the relays on the relay board and as well as giving me a baked Raspberry Pi! I use the +5 from the pi to drive the relay coils and the +3.3 to drive the opto isolators. Don’t believe that an external 5V would have saved the Pi though because they still share a common ground. Pi0W is only $10US if you shop around, though.

    #68339

    eraser215
    Participant

    Hi all,

    Noob here, trying to get the right information before making my purchase of an OSPi to use here in Australia. I have a question that I haven’t been able to answer conclusively based on the info in the forums and on the main commercial page.

    – Ray’s comment above says “Also we have started shipping OSPi version 1.5 since a few weeks ago. Version 1.5 uses an improved switching regulator and can provide up to 2amp current on +5V line so should be able to drive all RPis without needing external USB power supply.”. Does this mean that I can use the same power supply for the Pi and for the OSPi if I buy the right one? I am keen to just have a single supply rather than one for each. I want to be able to drive both devices and no more that 4 x 24VAC solenoid valves.

    – “Single power supply design — the same 24V AC sprinkler transformer powers both sprinkler valves and RPi.”. Would this be suitable for Australia (240V AC) with the right adaptor?

    Thanks for any help you can provide. I am a big open source fan so I am really keen to get this right and get my home sprinkler project happening. I am experienced enough with Linux and the Raspberry Pi to take care of the software side of things with no hassle, but I just want to get the hardware purchase right first time.

    Thanks all!

    #68343

    Ray
    Keymaster

    OSPi has a switching regulator that generates 5V DC from 24V AC input power. By “single power supply” it means the same 24V AC power is used to drive solenoid valves as well as powering RPi.

    For users outside of US/Canada/Mexico, please find 24V AC power supplies locally in your country. AC power adapters are NOT regulated and the ones we sell are only rated for 110V input. So it cannot be used in other countries.

    #68457

    eraser215
    Participant

    Hi Ray,

    Thanks for the info. Purchase completed, and very excited about the arrival of my OSPi here in Australia 🙂

Viewing 11 posts - 1 through 11 (of 11 total)
  • You must be logged in to reply to this topic.

OpenSprinkler Forums Hardware Questions OpenSprinkler Pi (OSPi) Raspberry Pi OSPi Model Guide