Reef-PI build thread, go big or go home

[Tristanzs]

See I was wondering about that, which headers to use. I obviously have most of the wiring complete for a second set of 8 it's just a matter of controlling them. I was thinking of talking to mike about a cleaner solution which would add another stack on top of our existing hat.

 

[Bigtrout]

See I was wondering about that, which headers to use. I obviously have most of the wiring complete for a second set of 8 it's just a matter of controlling them. I was thinking of talking to mike about a cleaner solution which would add another stack on top of our existing hat.

Thats what im doing...mount a uln2803 on a perma proto hat with a stackable header. You would stack it between the pi and mikes hat. It would be just like the power board on adafruit, except you use the pins that go to that unused header on mikes board(basically paralleling them just remember not to use them on mikes board once you do this. Since the board is between the pi and hat, i got 90 degree header pins to feed my second relay.
Another option is using a perma proto seperately and running 10 wires from power 1 header to that and 9 from there to the 2nd relay board.

 

[Tristanzs]

Wait so basically all I'd need to do is run the 9 pins that are on mike's board through a uln2803 and then out to the relay?

 

[Bigtrout]

Wait so basically all I'd need to do is run the 9 pins that are on mike's board through a uln2803 and then out to the relay?

Exactly, but you run to the uln2803 it needs power and ground as well as the 8 channels in...out of the uln to your relay board would be exactly like coming off the hat to your first relay...VCC and 8 channels.

 

[Diamond1]

See I was wondering about that, which headers to use. I obviously have most of the wiring complete for a second set of 8 it's just a matter of controlling them. I was thinking of talking to mike about a cleaner solution which would add another stack on top of our existing hat.

That's the main reason I chose the wykat hat. It is designed for 2 uln2803 chips.
You could always just hard wire the extra 8 outlets with a constant power supply.

 

[Tristanzs]

Hmm, so I'd just be running 9 pins out of my board to the uln and then another 9 directly to the relay. I'd use PB1 on the hat as my 5v and then 2-9 as the gpio lines?

 

[Bigtrout]

Ok from mikes board to uln2803
PB1 thru PB8------pin 1 thru 8 on uln
Pin 10(gnd)--------pin 9 on uln
Pin 1 5v-----------pin 10 on uln
From uln2803 to your relay board
Pin 18-11 uln2803-----in1 thru in8 relay
Pin 10------vcc on relay( yes this also has 5 volts on it

If you want to isolate that relay board like the first one, its the same as the first one, remove jdvcc jumper and put seperate 5v power to jdvcc and ground.

 

[Tristanzs]

Perfect now to order a uln2803 and the associated parts if I decide to put it in a pcb.

 

[Bigtrout]

Perfect now to order a uln2803 and the associated parts if I decide to put it in a pcb.

Order an 18 pin socket as well, then if something goes awry you can plunk in another easily

 

[Tristanzs]

Order an 18 pin socket as well, then if something goes awry you can plunk in another easily

Yeah that's why I'm thinking of building a PCB, dangit here I was trying to avoid pcb building. Alas it appears I must jump into the abyss and learn.

 

[Ranjib]

Some progress made today, I now have a functioning 8 channel switchable power strip. I realized I cannot do 16 with the way my hat is setup. Guess I should have read the documentation better. Going to look into options to expand to the full 16 but for now 8 should suffice. Also again huge shout out to the members of this forum for all their help without which I'd never be as far along as I am.

we'll have support for mcp23017 which will let you expand the GPIO,that should be helpful here. In fact , even pca9685 (16 channel pwm) can be used as 16 outlets.

 

[Ranjib]

Yeah that's why I'm thinking of building a PCB, dangit here I was trying to avoid pcb building. Alas it appears I must jump into the abyss and learn.

You dont have to. But its always fun to learn, key is to not stress up, and do a little at a time, and rip the benefit, while keep fun for future planned

 

[Tristanzs]

So I've wired up my float switches, they will turn on my ato. They however will not shut it off. I'm not sure exactly what is happening. I've tested each by itself with the same results.

 

[Tristanzs]

This is how my adaptor cables are built as per @Michael Lane .

 

[Tristanzs]

If I reverse polarity within reef pi I can get it to shut off via the switch. Then I have to reverse polarity again to get it to turn it on. This is what I've done to troubleshoot so far, I've isolated each switch individually, ran them in pairs, rewired the switch itself to ensure proper polarity, unplugged switch while relay was turned on by ato without a response from reef pi. I am thinking that it must be somewhere in the adapter cable itself.

 

[b4tn]

If I reverse polarity within reef pi I can get it to shut off via the switch. Then I have to reverse polarity again to get it to turn it on.

I cant see the color bands on your resistors. Do you for sure have the 4.3k ohm resistor going to ground and the 2k ohm resistor going to 5v on the dual resistor wire? The dual resistor circuit is a voltage divider. If the resistors are swapped it would output 1.5 volts instead of the intended 3.3. Not sure if thats the issue but doesnt hurt to check.

 

[b4tn]

https://www.allaboutcircuits.com/tools/resistor-color-code-calculator/

Just a handy quick resistor calculator I used.

 

[Tristanzs]

I am unsure Michael Lane made them for me.

 

[Tristanzs]

Ok I pulled the shrink wrap off one and can verify that the 2k resistor is going to +5v lead.

 

[b4tn]

Another thing I just thought of, are you waiting for the check interval? The relay will not turn off instantly with the switch. Say your interval is set to 60 seconds. If you trip the switch it will trigger the relay somewhere between 0-60 seconds and come on. When you change the state of the switch it will turn the relay off somewhere between 0-60 seconds. You can speed this up by changing your check interval to 10 seconds or less.