@dbemowsk Can heartily recommend the MP2315 type buck converters which were suggested to me here by @axillent as exceptionally efficient, spec says over 90% efficient and 3A, but 2A would probably be safer...
Have 2 of the USB type in my UPS (photo is somewhere here) as duty and standby, barely warm to the touch running the Pi3+Arduino gateway+HDD...

@jimy-aguirre I second @mfalkvidd 's suggestion of relocating the gateway (or indeed Gateway+Controller), 6dB is a brutal loss, cutting your signal to ca 25% from vague memory.
From the amplifier spec of 890-960 MHz your selected frequency is limited in range and penetration by default, even 433MHz nodes with full antennae would struggle to get 700m through structures.
No experience in using LoRa as suggested earlier, but many sing it's praises and it may offer a possible solution..

@mfalkvidd Had thought to query frequency but became increasingly confused by the information presented in relation to the 4 floor building and omnidirectional antennae, but the ethernet gateway on 8m of antenna cable stopped me dead at 6dB loss and 8dB ? and ceramic antennae which is impossible even as dBi. I relented from writing the analogy of the retired obstetrician getting 150% exam pass mark after changing engine spark plugs via the exhaust pipe, hence not banned...yet..
The principle driver for folks using high frequency seems to be the aesthetics of the device due a perception over size on antennae without some lateral thinking.
If for any reason the black 433MHz rubber ducks on my nodes offended my eye a lick of white paint would render them almost invisible against the white walls, but range has never ever been an issue through multiple barriers, and all are low power devices.
If I wanted vertical penetration through 4 floors I would align the antennae horizontal, a dipole or quad can be disguised in the rim of a lampshade or a picture frame, nobody lives in clean rooms, I plead the 5th when it comes to this place.
If this is not a theoretical but real scenario @Jimy-Aguirre, perhaps a little more information may help...

@ancalotoru said in Help for an irrigation system with a few inconveniences:

@zboblamont @skywatch I am looking forward to post tons of pictures and a full tutorial with code and electronics. I will get all the pieces in September so I will have to wait for a month....

Besides I have a question. Is better to have a 9v batteries to run the valves and then regulate its voltage to 3.3v in order to run all the sensors and the arduino, or is better to have two separated batteries? One for the arduino node and another exclusive one to drive the valves

Thank you!ed

I would suggest no. It may seem initially energy economito consolidate supplies, but a separate supply for the Node ensures it tells you when the 9v valve supply is getting close to failure to enable change-out before failure. If you are irrigating twice a day, that gives you a 12 hour minimum to change the valve actuator battery.
If you look at the mAh capacity of a PP3 v AA the lfespans are starkly different ;).
Your original control was built as a 9v remote head (?), it stands to reason that a quick low voltage burst to relay/fet the 9v battery at the "Node" should be sufficient to drive the latching valves, secure yet energy separated.
Hope that makes sense...

@sundeep-goel Glad you found a solution, hopefully it will continue to prove reliable over time in your environment, presumably dust is not a problem from the presence of water, nor condensation through ventilation (loose lid)
Out of curiosity, what the range is that version, I've seen 1m and 2m quoted for the same model number..?

@ancalotoru The power demand will probably be dictated by the valve box operating at a different voltage, but since it was designed for battery power it should not be huge.
Agree with @skywatch recommendation of a PSU if it is viable but perhaps look at battery backup also if you get power cuts as were the bain of my life here...
Looking forward to your finalised pictures, good luck...

@skywatch "I can't really add more to this other than to say that if the batteries in the remote won't work, warm them under your armpits for a few minutes and try again - I bet they work!" - For the cost of a few cells? I'm Scottish, but presume you know it was the Scots who invented copper wire by fighting over a penny....

Yep Lead/Acid gel on the UPS for the Gateway/Controller, but that's indoors where it is generously warm even when it's Siberian outside...

@skywatch I'm no chemistry engineer, but this generalisation I've heard said previously as an undisputed fact, hence my posting last year's voltage record for one of the most exposed nodes...
The decay is no greater than with any of the internal nodes, and with last winter down to -20 you might expect evidence of it, yet the cheap standard alkalines sailed through it unperturbed..
The voltage drop for a month in summer failing to connect to the Gateway was colossal by comparison, hence the UPS went up my priority list...

@skywatch said in Help for an irrigation system with a few inconveniences:

This is because all batteries are based on a chemical reaction and the colder the temperature the less energy there will be in the atoms. Below 0C the batteries will probably die very quickly in use, but they will last longer if stored this way - I hope that makes sense!.....

Having seen this stated previously as a cast-iron fact (and I do not dispute the theory), I remain forever in awe of the cheap alkalines used here surviving -20 winters and 36 degree summers...
Possibly the type of temperature ?
The biggest voltage drop found here was when the Gateway crashed and the Node attempted to contact a dead end....

@ancalotoru Glad cabling made sense, it will solve your primary problem of communications with a wall or pole mount.
I noted "Rain bird" stock 3 core and 7 core cables but in 75m drums. Presumably your dead device will have a short connecting cable in the box to cross check which version you need, then order an equivalent in the market at probably cheaper cost for just over the length you actually require... I suggest putting the cable inside some conduit before burial, that way it gets damaged for some reason you can pull through a replacement.
If you go for a pole or wall mount for your node, can recommend this type of light switch box (433MHz gas meter node) as an AA battery holder fits neatly under the transparent cover making changing batteries really easy just by unlatching the hinged lid, although still not needed yet after 2 years running...
Good luck...