Raspberry Pi OSPi Model Guide

[jptaranto]

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

[Ray]

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.

[jptaranto]

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.

[jptaranto]

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

[psmedley]

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.

[jptaranto]

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.

[JimS]

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.

[Leesburg_Dave]

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.

[eraser215]

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!

[Ray]

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.

[eraser215]

Hi Ray,

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

[sprinklr]

Hi,

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.

Thanks for confirming this.
What sort of amperage is needed to power both (RPi + valve) using a single 24 VAC power supply ?

I’m also in Australia and the choice is rather limited. I just found these 2 PS:
– 24VAC 1A
– 24VAC 3A

Which one would be better ? (I have a RPi 3 B)

Thanks !

[Ray]

Both are ok. If you don’t open more than 2 zones at the same time, then 1A is sufficient. If you need more zones to turn on simultaneously, then go with 3A.

[sprinklemedaisy]

I have a RPi 2 Model B will ram and cpu power wise this be fine for opensprinkler to run ?

Alex

[Ray]

I think so.

[sprinklemedaisy]

Sorry missed this at the time thanks @ray

[sprinklemedaisy]

I have literally just got to assembling my ospi i have an early model i belive “V1 – Model B Revision 1.0”

I understand now the case is not campatible but is the board, do i just shift to either side leaving 7 sockets open, if so which side ? I would like top use this model not to waste and also to save on another power adaptor 🙂

Thanks

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[Ray]

Here are how the pins are supposed to be connected: imaging flipping your RPi down, with the male pins facing the female pins on OSPi, and that the Ethernet jack is pointing to the right, then your RPi’s 2×13 pins plug into exactly the first (from left) 2×13 pins on OSPi. In other words, with the RPi facing down, the RPi pins and OSPi pins align on the left.

[sprinklemedaisy]

Perfect thanks Ray i got it 🙂

Just didnt want to fry anything.

Alex

[Author]

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