reef-pi :: An opensource reef tank controller based on Raspberry Pi.

[Ranjib]

Anyone know if these two parts the same thing? The one from mouser is cheaper and available for me.

Im gather parts to build the powerstrip using Ranjibs guide.

UlN2803 darlington trasistor
https://www.adafruit.com/product/970

And

ULN2803A Darlington Transistors Eight NPN Array

https://www.mouser.com/ProductDetail/STMicroelectronics/ULN2803A?qs=sGAEpiMZZMvAvBNgSS9LqpP7ived4CP2

Yes, they'll work just fine.

 

[COCOBBALL]

I have to buy a 3

Yes, they'll work just fine.

Amazing! I was able to source 90% of my parts from a local distributor with 1 hour pickup!

If you live close to DFW Texas check out Mouser.

Thanks again Ranjib!

 

[Ranjib]

Amazing! I was able to source 90% of my parts from a local distributor with 1 hour pickup!

If you live close to DFW Texas check out Mouser.

Thanks again Ranjib!

I also have Jameco walking distance :-) . Some days I just go in the afternoon and stare at different connectors. Its so convenient, its like "Safeway" for electronics. I bet mouser is even more awesome (Costco of electronics :-) ) Question: Does Texas instrument ICs easy to source from Texas?

 

[COCOBBALL]

I also have Jameco walking distance :-) . Some days I just go in the afternoon and stare at different connectors. Its so convenient, its like "Safeway" for electronics. I bet mouser is even more awesome (Costco of electronics :-) ) Question: Does Texas instrument ICs easy to source from Texas?

I couldnt answer that ive never had a reason to try. I'll look into it

 

[b4tn]

If you are looking for parts for your reef pi build that are a bit cheaper than adafruit or amazon this place has good prices and free overnight shipping. The optical water sensor is about 1/2 the rice of amazon.
https://www.arrow.com/en/products/sen0205/dfrobot

@Diamond1 i don’t know how these guys stay in business. But I ordered $8 in parts last night at 8pm and they are sitting on my table now. They sent two fedex overnight packages.

 

[Erica-Renee]

@Diamond1 i don’t know how these guys stay in business. But I ordered $8 in parts last night at 8pm and they are sitting on my table now. They sent two fedex overnight packages.

Its the LARGE overnight orders from Companies i suspect.. They buy way more parts then they would normally sell . Allowing them to sell at lower prices. Instead of tear pricing they sell some pieces off for a loss to get the BIG Company orders by being able to sell big quantities cheaper .

 

[Ranjib]

Its the LARGE overnight orders from Companies i suspect.. They buy way more parts then they would normally sell . Allowing them to sell at lower prices. Instead of tear pricing they sell some pieces off for a loss to get the BIG Company orders by being able to sell big quantities cheaper .

Wont it cost a lot if they then distribute it in small parts, due to shipping?
This is beyond me...

 

[Erica-Renee]

Wont it cost a lot if they then distribute it in small parts, due to shipping?
This is beyond me...

my guess is they are not selling that many small part orders ... But you could be right . I mean small Quantity orders .I bet not very many people order a few bucks or so worth of parts..

 

[LionHeart2017]

Think it's just business to them, they'll have a contract with the delivery service, can you imagine now a days the amount of deliveries due to internet shopping, it must be phenomenal compared to 15 years ago and delivery companies are bigger than ever

 

[b4tn]

Is it possible that I have a bad ULN2803 or am I not understanding things correctly. I have the chip plugged in to the socket sorted like it is in the guide, it has a solid 12 volts at 0 and com, I verified continuity with all pins to Board to jumpers, and I have verified pi is giving the inputs 3.24 volts that is controllable on or off and working. But the outputs are only going to .56 volts when switched on and .1 volts when switched off. Shouldn’t I be getting 12 volts on the output?

 

[Ranjib]

Is it possible that I have a bad ULN2803 or am I not understanding things correctly. I have the chip plugged in to the socket sorted like it is in the guide, it has a solid 12 volts at 0 and com, I verified continuity with all pins to Board to jumpers, and I have verified pi is giving the inputs 3.24 volts that is controllable on or off and working. But the outputs are only going to .56 volts when switched on and .1 volts when switched off. Shouldn’t I be getting 12 volts on the output?

Share your circuit image. It acts as a sink, so you want to touch 12V+ one end of the multimeter and the ULN2803 output on the other end of the multimeter.

 

[b4tn]

Share your circuit image. It acts as a sink, so you want to touch 12V+ one end of the multimeter and the ULN2803 output on the other end of the multimeter.

Ahh, ok. It’s grounding the output. I was treating it like the input. It works and tested fine. Thanks.

 

[Diamond1]

Yeah those guys are great I've ordered a bunch of stuff from them and haven't been disappointed yet. I got my new Pi and a proto from them this week for less than $35 shipped.

 

[LionHeart2017]

@Ranjib and all who enjoy this thread.

Can we talk battery backup to get into reef-pi at some point and looking at ways to implement it using the raspberry-pi to trigger the back up under mains power going off.

I'm thinking something simple as being able to keep a controlable wave maker that's all ready mains powered running for like 8 hours from a 12v battery, what do you all think?

 

[Ranjib]

I just wanted to say thank you to @Ranjib and all of the other contributors. I have my reef-pi up and running, and coordinating well with my home automation (Home Assistant running on another Pi) to get my 15 gallon nano to follow a Bali, Indonesia reef biotope. I'm working on adding an auto feeder, but for now it's doing everything I need with ATO and Doser peristaltic pumps, a float switch, a Kessil light, wavemaker and temp control. I went with Tuya power strips instead of setting up relays so it stayed compact enough for me to 3D print the housing. I think it's all made a very tidy controller even if it looks like a mess on the inside. :)

@sfgabe this is a 3d printed housing? If so, do you have the design files somewhere, like thingiverse?

 

[Ranjib]

@Ranjib and all who enjoy this thread.

Can we talk battery backup to get into reef-pi at some point and looking at ways to implement it using the raspberry-pi to trigger the back up under mains power going off.

I'm thinking something simple as being able to keep a controlable wave maker that's all ready mains powered running for like 8 hours from a 12v battery, what do you all think?

We are having a discussion here already: https://www.reef2reef.com/threads/reef-pi-new-daugther-board.478458/#post-5359595

 

[Erica-Renee]

@sfgabe this is a 3d printed housing? If so, do you have the design files somewhere, like thingiverse?

I just created a account on there. Will soon start working on designs for my reef-pi project.. @Ranjib once i get this 3d modeling thing all worked out . Or a logo you want .. we can work to get them in your hands.. I now have the 3d printer and for your maker fairs.. I can print and send you any Vinyl cut lettering or decals you need ( i have a vinyl cutter/ plotter machine) . If you are still doing those. It cost nothing to print the product as the equipment was bought and paid for to do other projects.. ..

 

[pdisner]

I'm not sure if the 2.2k would work or not.
I got one of these from amazon. I don't think I'll be running out of resistors any time soon.
https://www.amazon.com/gp/product/B0792M83JH/ref=oh_aui_detailpage_o01_s00?ie=UTF8&psc=1

Awesome thanks for posting that.

 

[sfgabe]

this is a 3d printed housing? If so, do you have the design files somewhere, like thingiverse?

Yes, though it's very much V1. I can already see some thing that should be changed, but I can put it on thingiverse tomorrow for anyone who wants to make their own version.

 

[Ranjib]

Yes, though it's very much V1. I can already see some thing that should be changed, but I can put it on thingiverse tomorrow for anyone who wants to make their own version.

Yes please, and tag it with #reef-pi