Another reef-pi build.
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b4tn
Valuable Member
@Ranjib the current rating on a power supply is not how much it puts out but how much it is capable of supplying. I built a 20 amp 0-50v bench power supply in high school that would sit on my desk and power just about anything I would throw at it big or small. In this case the lm2596 and Proto board will never see more than what the raspberry requires. The 12 volt side however could require up to 3 additional amps depending on which motors I decide on for the dosers. The ones I was looking at had a peak of 1.5 amps each. I sized the power supply based on the recommended 2.5 amp for raspberry and the possibility of up to 3 amp requirement for the motors. All 12 volt power is drawn directly from the source and all 5 volt power is drawn through the lm2596. 5 amps is probably ly overkill but at least it’s available if required.
Yes. I was referring to scenario where you are creating a 5v rail from the lm2596 output , pi, pca9685, ato , ph sensor etc, and it’s pretty easy to reach that 3a limit. If you are aware of this then it’s all good
. For just pi, this is definitely more than enough
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b4tn
Valuable Member
I made a ton of progress last night. My wife was less than pleased when she got home from work and I had taken over her dining room table but she is the one that said the extra room cant be a man cave so its her fault lol.
The new connectors for ATO, temp, and aviation connectors for the lights where much larger than I expected! My box is starting to look a little like Swiss cheese but I got all the holes measured and cut. Due tot he size of the connectors I had to do a complete re-wire. Which is not bad anyway because I wanted to beef up the wires a little for the 12 volt power side. I hit three hardware stores looking for 22awg stranded wire with no luck. My backup plan was to re purpose some old Ethernet cable but I really wanted more color options. In the end I went ahead and used the cat5 cable so I didnt have to wait for another order to get started. On the plus side of using twisted pair for power will help with noise issues. I had to remove the proto HAT and solder some more pins. In particular I needed to add pins for 3.3v and ground to power the the PCA9685, Pins for SCL and SDA for the I2C control, and I went ahead an soldered pins on all the remaining GPIO outputs for the light relays or whatever else I might need them for. Lastly I soldered in som pins to my ATO circuit to run to float switches in parallel. I will be running my float switches with both a high and low level switch like so.
And my helper was once again sleeping on the job.
There is so much going on here I pretty much gave up trying to make it look pretty. Its going to have a lid anyway when its done lol
If you look very close in the pic under the relay circuit you can see a bit of cardboard with something shiny protruding out. That is my make shift EMF filter, due to space issues the power cord for the pi runs directly underneath it. I basically laid foil over the power cord and covered it with cardboard so nothing shorts on the bottom of the relay board. It may not do anything, it may not even be necessary but I doesn't hurt anything so I figured what the heck. The idea came from this video.
Minus wiring the connectors everything is assembled. I went ahead and powered it up to test and the PCA9685 worked first go around using 3.3v to dim an LED I had laying around. The doser circuit still works, and all the other little things still work. but...... The relay will not fire. Seems I was not paying attention when I ordered the relay and the minimum input voltage to trigger the relays is 5v. It was nearing midnight and I was tired and about to give up for the night but @Ranjib suggested testing the voltage with things disconnected and so I ran a few tests and thats when I realized the problem. I was trying to avoid having to use a driver for relays since I dont have room for another ULN2803 but I do have 7 more lines on my perma Proto HAT which will be perfect for space for a pair of transistors. Not a huge problem just more waiting for parts to get here in the mail. I will be doing this using PN2222 and a 1k resistor. The only difference is the relay already has a flyback diode built in and the supply source will be 12 volts instead of 5.
The new connectors for ATO, temp, and aviation connectors for the lights where much larger than I expected! My box is starting to look a little like Swiss cheese but I got all the holes measured and cut. Due tot he size of the connectors I had to do a complete re-wire. Which is not bad anyway because I wanted to beef up the wires a little for the 12 volt power side. I hit three hardware stores looking for 22awg stranded wire with no luck. My backup plan was to re purpose some old Ethernet cable but I really wanted more color options. In the end I went ahead and used the cat5 cable so I didnt have to wait for another order to get started. On the plus side of using twisted pair for power will help with noise issues. I had to remove the proto HAT and solder some more pins. In particular I needed to add pins for 3.3v and ground to power the the PCA9685, Pins for SCL and SDA for the I2C control, and I went ahead an soldered pins on all the remaining GPIO outputs for the light relays or whatever else I might need them for. Lastly I soldered in som pins to my ATO circuit to run to float switches in parallel. I will be running my float switches with both a high and low level switch like so.
And my helper was once again sleeping on the job.
There is so much going on here I pretty much gave up trying to make it look pretty. Its going to have a lid anyway when its done lol
If you look very close in the pic under the relay circuit you can see a bit of cardboard with something shiny protruding out. That is my make shift EMF filter, due to space issues the power cord for the pi runs directly underneath it. I basically laid foil over the power cord and covered it with cardboard so nothing shorts on the bottom of the relay board. It may not do anything, it may not even be necessary but I doesn't hurt anything so I figured what the heck. The idea came from this video.
Minus wiring the connectors everything is assembled. I went ahead and powered it up to test and the PCA9685 worked first go around using 3.3v to dim an LED I had laying around. The doser circuit still works, and all the other little things still work. but...... The relay will not fire. Seems I was not paying attention when I ordered the relay and the minimum input voltage to trigger the relays is 5v. It was nearing midnight and I was tired and about to give up for the night but @Ranjib suggested testing the voltage with things disconnected and so I ran a few tests and thats when I realized the problem. I was trying to avoid having to use a driver for relays since I dont have room for another ULN2803 but I do have 7 more lines on my perma Proto HAT which will be perfect for space for a pair of transistors. Not a huge problem just more waiting for parts to get here in the mail. I will be doing this using PN2222 and a 1k resistor. The only difference is the relay already has a flyback diode built in and the supply source will be 12 volts instead of 5.
Thank you for sharing the detailsI made a ton of progress last night. My wife was less than pleased when she got home from work and I had taken over her dining room table but she is the one that said the extra room cant be a man cave so its her fault lol.
The new connectors for ATO, temp, and aviation connectors for the lights where much larger than I expected! My box is starting to look a little like Swiss cheese but I got all the holes measured and cut. Due tot he size of the connectors I had to do a complete re-wire. Which is not bad anyway because I wanted to beef up the wires a little for the 12 volt power side. I hit three hardware stores looking for 22awg stranded wire with no luck. My backup plan was to re purpose some old Ethernet cable but I really wanted more color options. In the end I went ahead and used the cat5 cable so I didnt have to wait for another order to get started. On the plus side of using twisted pair for power will help with noise issues. I had to remove the proto HAT and solder some more pins. In particular I needed to add pins for 3.3v and ground to power the the PCA9685, Pins for SCL and SDA for the I2C control, and I went ahead an soldered pins on all the remaining GPIO outputs for the light relays or whatever else I might need them for. Lastly I soldered in som pins to my ATO circuit to run to float switches in parallel. I will be running my float switches with both a high and low level switch like so.
And my helper was once again sleeping on the job.
There is so much going on here I pretty much gave up trying to make it look pretty. Its going to have a lid anyway when its done lol
If you look very close in the pic under the relay circuit you can see a bit of cardboard with something shiny protruding out. That is my make shift EMF filter, due to space issues the power cord for the pi runs directly underneath it. I basically laid foil over the power cord and covered it with cardboard so nothing shorts on the bottom of the relay board. It may not do anything, it may not even be necessary but I doesn't hurt anything so I figured what the heck. The idea came from this video.
Minus wiring the connectors everything is assembled. I went ahead and powered it up to test and the PCA9685 worked first go around using 3.3v to dim an LED I had laying around. The doser circuit still works, and all the other little things still work. but...... The relay will not fire. Seems I was not paying attention when I ordered the relay and the minimum input voltage to trigger the relays is 5v. It was nearing midnight and I was tired and about to give up for the night but @Ranjib suggested testing the voltage with things disconnected and so I ran a few tests and thats when I realized the problem. I was trying to avoid having to use a driver for relays since I dont have room for another ULN2803 but I do have 7 more lines on my perma Proto HAT which will be perfect for space for a pair of transistors. Not a huge problem just more waiting for parts to get here in the mail. I will be doing this using PN2222 and a 1k resistor. The only difference is the relay already has a flyback diode built in and the supply source will be 12 volts instead of 5.
, this is a great read
crusso1993
7500 Club Member
Were you going to exit the hobby had you broken your tank down?
ScottBrew
Active Member
That was the thought. I've had SW tanks on and off for 30 plus years so wouldn't have been permanent. We have plans for a 300 plus gallon down the road but requires the kitchen to be remodeled first with a built in table and then could give up the dining room to make room for the tank.
OP
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b4tn
Valuable Member
These are the connectors I was so excited about. They are a lot bigger and bulkier than I expected but man they are rock solid! And super easy to use. It takes 2 minutes to swap temp probes if needed no soldering involved. It’s nice to not have to fiddle with the temp probe connectors whenever I move the box. I got both 2 and 3 pin ones for the temp probes and for the float switches.
Diamond1
Valuable Member
These are the connectors I was so excited about. They are a lot bigger and bulkier than I expected but man they are rock solid! And super easy to use. It takes 2 minutes to swap temp probes if needed no soldering involved. It’s nice to not have to fiddle with the temp probe connectors whenever I move the box. I got both 2 and 3 pin ones for the temp probes and for the float switches.
I was considering those connectors to but decided to try the mini xlrs. They do look really solid.
crusso1993
7500 Club Member
I, for one, am happy you stuck around. You have been a big help to quite a few members building reef pi controllers!
OP
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b4tn
Valuable Member
Honestly the mini xlr probably would have been a better choice. They are probably more compact and I could have fit the aviation connectors on the front with all the others instead of on the side. But the screw terminals which I normally don’t like but are solid also are nice. I tested all my temp probes in minutes. Have you taken any pictures yet of the xlr connectors installed?
OP
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b4tn
Valuable Member
@ScottBrew I can’t find any specs for them but I am willing to bet they can take some serious current. They are very stout. I pretty much squashed the bug with a sledge hammer on this one lol
ScottBrew
Active Member
That's a two way street!
crusso1993
7500 Club Member
That's slightly true as some of us (you and others) are farther along the hardware and coding path than than some others (me and some)!
I've been planning on learning Python but have had a tough time getting to it.
crusso1993
7500 Club Member
BTW - the last time I did any coding was on Fortran and Cobol in the mid 80's! Ha!
ScottBrew
Active Member
Me, coding? No! Code doesn't "speak" to me, the hardware does. I am a software USER. I like building stuff, that's probably as much of the appeal to this hobby as the living things in the tank. I can USE software, navigate file systems, edit files and I'm really good at using Google as well as following directions from people like @Ranjib who know what all the code means! The machines I work on have Linux (and older Unix based systems) as their operating system and I've gained a lot of knowledge from beating my head against the proverbial wall with them.
