CraftBeerPi - Raspberry Pi Software

[papacap]

• I'm having trouble understanding how I hook the temp probes in and the pump (do I need a relay? How would that wire up?).

I am not an expert but I very recently did a similar build. Any breakout hat should work although personally I just prototyped onto a through-hole pcb and used some jumper wires.
I'd recommend getting a relay module (like this https://www.amazon.com/dp/B0057OC6D8/) for the pumps. There's no need to run pumps on an ssr because they don't need fast switching. I set up the module so I have 3 position switches and the pumps can run manually or with the digital control.
Temperature probe should be simple to hook up if you are using a ds18b20. Its been covered many times in this thread but you need a pull up resistor between the supply and data lines.
One issue I see with your diagram is that the input side of your ssr needs to return current to the supply for the pi. You will have 2 "grounds" in your build. One is the earth which is for safety on the high voltage stuff. The other is the ground for the rpi which is the V- of your 5v power supply.

Happy to answer more questions if I can help. I'll try to get some photos of my project up when I get a chance.

 

[Lalo_uy]

Hey guys, I've been on here and in the Electric Brewery section looking at wiring designs for several months. I've decided to go with RPi and it seems like CBPi is the best supported open source solution, so I'm ready to pull the trigger on a CBPi brew controller. I've been working on my parts list and drawing, but I'm a little confused about how to bring it all together.

• I've bought an RPi 4B. Will any GPIO breakout HAT work? This one seems pretty straightforward: Amazon.com
• I'm trying to blend the safety of a mechanical system (ala The Electric Brewery) with the GUI control of a computer based controller. To that end, I've tried to copy some of Doug's drawings, while replacing the PID with the RPi (using the CBPi Wiring drawing attached in this thread and here). See my first attempt at combining this attached.
• I'm having trouble understanding how I hook the temp probes in and the pump (do I need a relay? How would that wire up?).
• I'm not entirely sure I have the element/SSR hooked up right for this.

Sorry for the noob questions here. This is my first RPi and my first control panel, but I'm looking forward to taking my brewing to the next level. I really appreciate the help!!

It is better to put some gain between the gpio and the SSR. A transistor or ULN2003 will do. Very few SSR really triger at 3v.
The wiring of therms si correct in the image. The pullup could be lower, 3k3 ir 2k7 if the wires are long. But allways connect it to 3.3V, no 5v on gpios. The therm vcc is ok at 5v

 

[LBussy]

I am not a CBPi user let alone an expert. I do mess with automation, Pis, and controllers a lot so that's my content for answering your questions. Just giving a disclaimer.

I've bought an RPi 4B. Will any GPIO breakout HAT work? This one seems pretty straightforward: Amazon.com

To the extent that it gives you a screw terminal versus a pin header, sure. That looks like a nice one. I may pick one up since I've sort of half been hunting one. The Pi 4 will do best with a fan. Any application without a fan leads to throttling in my experience. The Pi 4 is quite a bit more powerful, I like it a lot.

I'm trying to blend the safety of a mechanical system (ala The Electric Brewery) with the GUI control of a computer based controller. To that end, I've tried to copy some of Doug's drawings, while replacing the PID with the RPi (using the CBPi Wiring drawing attached in this thread and here).

Love this idea. I'm with you on the combination of safety and automation. Have had that sort of approach in the back of my brain for a while, so I am interested to see how you get it done. I've been thinking of a way to allow both, which is probably more complicated than you are considering. I'll be interested to see how you come along with this.

I'm having trouble understanding how I hook the temp probes in and the pump (do I need a relay? How would that wire up?).

In general, a OneWire sensor uses power (and these are 3v3 or 5v tolerant), ground, and a data pin. You connect power to data with a resistor (pull up), the value depending on the voltage you use and the specific application. Generally, we get pretty good results with a 2k2 resistor when powering with 3V3, and 4k7 when using 5v. I believe the Pi supplies 5v but the GPIO requires 3V3.

This is a pretty good article covering temp sensors in genera which would not be a bad read if you are coming in cold.

The pump is another thing. The Pi will not supply very much power, but small relays or an SSR (preferred I would think) is what you'd apply there. The purpose-built Pi hats for CBPi use FETs I think to provide more amperage for higher loads. Those are easier and more capable, but so long as you understand that there are current draw limitations per pin and per rail, you will be fine without those hats. You'll need to line up the SSR requirements with the rail capabilities.

Hopefully, my answer was not too basic for you, and it helps some.

 

[Wootonius]

I'd recommend getting a relay module (like this https://www.amazon.com/dp/B0057OC6D8/) for the pumps. There's no need to run pumps on an ssr because they don't need fast switching. I set up the module so I have 3 position switches and the pumps can run manually or with the digital control.

Thanks for jumping in on this, papacap! Gotcha on the relay, thanks for that.
I like the idea of being able to control those manually if necessary. I'll try to add in that circuitry. I'm thinking now that pump control within the CBPi panel can be pushed to V2 since I'm eager to get this thing started so I can get to brewing with it!!

Temperature probe should be simple to hook up if you are using a ds18b20. Its been covered many times in this thread but you need a pull up resistor between the supply and data lines.

Hmmm, I had been planning to use one of the RTD PT100 sensors from Auber, but after reading up a bit more, I see that the ds18b20's would be a simpler implementation with the Pi. And yeah, I left off the resistor. I'll add that in.

One issue I see with your diagram is that the input side of your ssr needs to return current to the supply for the pi. You will have 2 "grounds" in your build. One is the earth which is for safety on the high voltage stuff. The other is the ground for the rpi which is the V- of your 5v power supply.

If I'm understanding what you're saying here, I need to attached that green ground line to either the RPi "GND" terminal or to the V- of the 5v power supply. Right?

Thanks again!

 

[papacap]

Thanks for jumping in on this, papacap! Gotcha on the relay, thanks for that.
I like the idea of being able to control those manually if necessary. I'll try to add in that circuitry. I'm thinking now that pump control within the CBPi panel can be pushed to V2 since I'm eager to get this thing started so I can get to brewing with it!!

To elaborate a bit. I use a 3 position switch to control the relay module for the pumps. The switch outputs are bridged and go to the relay. One input is a GPIO pin and the other is the rpi gnd pin (relays turn on when you apply gnd to the input pin of the relay and off with +5v). If this kind of control is something you want eventually I'd recommend getting 3 position switches which you can use as a simple switch but gives you the option to add digital control later.

Hmmm, I had been planning to use one of the RTD PT100 sensors from Auber, but after reading up a bit more, I see that the ds18b20's would be a simpler implementation with the Pi. And yeah, I left off the resistor. I'll add that in.

Personally I have PT100's on my mash ton and hot liquor tank and then a ds18b20 on the boil kettle. Wiring the PT adds a bit more complexity but its not too bad if you care about the improved accuracy (or you already have them in my case). The main thing is you need a max31865 analog digital converter for each PT sensor.

If I'm understanding what you're saying here, I need to attached that green ground line to either the RPi "GND" terminal or to the V- of the 5v power supply. Right?

Thats correct. To be clear only the ssr and relay module go to the ground (called -V usually) on the 5v supply (or rpi gnd pin). All high voltage stuff should use the earth ground.

I'll also add that I use a ULN2803 to control my ssrs but if you have high quality ssr you should be fine with using GPIO pins. Just be sure to drive them with 5v even if they claim to work on 3v.

 

[day_trippr]

In general one should not connect a DC return to AC safety ground.
An AC to DC power supply already provides a DC "ground" reference to the scope of its output domain, and keeping it separate from the AC side is almost always a good idea...

Cheers!

 

[Wootonius]

It is better to put some gain between the gpio and the SSR. A transistor or ULN2003 will do. Very few SSR really triger at 3v.
The wiring of therms si correct in the image. The pullup could be lower, 3k3 ir 2k7 if the wires are long. But allways connect it to 3.3V, no 5v on gpios. The therm vcc is ok at 5v

Thanks Lalo_uy. I'm looking at using this 40A SSR from Auber:
https://www.auberins.com/index.php?main_page=product_info&cPath=2_30&products_id=30It says it will trigger at 3V 3-30mA, but I understand that's at the bottom limit. Does anyone have experience with this one?

Using the ULN2003: I did a little research, and I think I understand how it works. If I connect the GPIO18 to pin 1, and the 5V from the DC power supply to COM pin 9, GND to pin 8. Then output 1 pin 16 goes to the SSR + signal side and the SSR - signal side to the RPi GND. Then when the RPi switches 3.3V on at GPIO18, ULN2003 will route the 5V from the DC PS to the SSR, turning it on. If that's all correct, then the beauty is that I could GPIO23 to ULN Input 2 pin 2 to route the 5V out pin 15 (Output 2) for my second SSR/Element later on. Is that about right?

 

[papacap]

Using the ULN2003: I did a little research, and I think I understand how it works. If I connect the GPIO18 to pin 1, and the 5V from the DC power supply to COM pin 9, GND to pin 8. Then output 1 pin 16 goes to the SSR + signal side and the SSR - signal side to the RPi GND. Then when the RPi switches 3.3V on at GPIO18, ULN2003 will route the 5V from the DC PS to the SSR, turning it on. If that's all correct, then the beauty is that I could GPIO23 to ULN Input 2 pin 2 to route the 5V out pin 15 (Output 2) for my second SSR/Element later on. Is that about right?

Its possible that there are ways to wire the uln that I am not familiar with but mine is wired differently. Essentially I have the ssr+ connected directly to the +5v supply (or 5v on rpi). Then the ssr- goes to the output pin of the uln. When 3v is applied to the input pin. Current will flow through the uln output pin and out the uln gnd pin which should also be connected directly to the 5v ground reference (or gnd on rpi). The uln com pin should be at 5v for it to function properly. This essentially uses the uln as a relay controlling the return current from the ssr. The beauty of this layout is it let's you run the ssr with 5v I stead of 3v using only a 3v signal from the pi. I'm using the cheapest of cheap China ssrs (3v-32v) and I have no issue triggering them with this setup.

 

[Lalo_uy]

I agree with papacap. Put the uln outputs in the ground side (-) of the ssr.

 

[Wootonius]

I am not a CBPi user let alone an expert. I do mess with automation, Pis, and controllers a lot so that's my content for answering your questions. Just giving a disclaimer.


To the extent that it gives you a screw terminal versus a pin header, sure. That looks like a nice one. I may pick one up since I've sort of half been hunting one. The Pi 4 will do best with a fan. Any application without a fan leads to throttling in my experience. The Pi 4 is quite a bit more powerful, I like it a lot.


Love this idea. I'm with you on the combination of safety and automation. Have had that sort of approach in the back of my brain for a while, so I am interested to see how you get it done. I've been thinking of a way to allow both, which is probably more complicated than you are considering. I'll be interested to see how you come along with this.



In general, a OneWire sensor uses power (and these are 3v3 or 5v tolerant), ground, and a data pin. You connect power to data with a resistor (pull up), the value depending on the voltage you use and the specific application. Generally, we get pretty good results with a 2k2 resistor when powering with 3V3, and 4k7 when using 5v. I believe the Pi supplies 5v but the GPIO requires 3V3.

View attachment 718150
This is a pretty good article covering temp sensors in genera which would not be a bad read if you are coming in cold.

The pump is another thing. The Pi will not supply very much power, but small relays or an SSR (preferred I would think) is what you'd apply there. The purpose-built Pi hats for CBPi use FETs I think to provide more amperage for higher loads. Those are easier and more capable, but so long as you understand that there are current draw limitations per pin and per rail, you will be fine without those hats. You'll need to line up the SSR requirements with the rail capabilities.

Hopefully, my answer was not too basic for you, and it helps some.

Thanks for the detail here and the links, those will come in handy! I think I will take a phased approach on this. Phase one will be getting the basic Pi with SSR circuit, element and one temp probe up and running. I'll just manually switch my AC Pump using the switch built into its power cord for now and use my old Term Pro in the Mash. From there I can begin electric brewing and develop some proficiency with the Pi. From there it'll be easier to add functionality, controlling the pump(s) and so forth. Eventually I want to roll control my fermentation chamber into the CBPi system. It's currently a chest freezer controlled by an ITC-1000.

 

[NeoBrew]

Thanks for the detail here and the links, those will come in handy! I think I will take a phased approach on this. Phase one will be getting the basic Pi with SSR circuit, element and one temp probe up and running. I'll just manually switch my AC Pump using the switch built into its power cord for now and use my old Term Pro in the Mash. From there I can begin electric brewing and develop some proficiency with the Pi. From there it'll be easier to add functionality, controlling the pump(s) and so forth. Eventually I want to roll control my fermentation chamber into the CBPi system. It's currently a chest freezer controlled by an ITC-1000.

CBPi is a really nice system for brewing. I've been using it for a few years. I don't recommend it for fermentation. The Pi is just not reliable enough to trust with a long term fermentation. I would suggest you look at BrewPi or Fermentrack for that application.

 

[LBussy]

The Pi is just not reliable enough to trust with a long term fermentation. I would suggest you look at BrewPi or Fermentrack for that application.

I'm a little biased, but I agree. Just because the Pi *can* do it doesn't mean it's a good idea. Anyone who has used BrewPi or Fermentrack has run into a case where the UI is no longer working (the Pi) but the Arduino or ESP8266 is happily controlling things in the background. A computer is not a controller.

You can pull information into CBPi I would imagine, and push settings to the controllers, but using a Pi for the actual control is no bueno IMHO.

 

[Wootonius]

Its possible that there are ways to wire the uln that I am not familiar with but mine is wired differently. Essentially I have the ssr+ connected directly to the +5v supply (or 5v on rpi). Then the ssr- goes to the output pin of the uln. When 3v is applied to the input pin. Current will flow through the uln output pin and out the uln gnd pin which should also be connected directly to the 5v ground reference (or gnd on rpi). The uln com pin should be at 5v for it to function properly. This essentially uses the uln as a relay controlling the return current from the ssr. The beauty of this layout is it let's you run the ssr with 5v I stead of 3v using only a 3v signal from the pi. I'm using the cheapest of cheap China ssrs (3v-32v) and I have no issue triggering them with this setup.

Ok, I've added the ULN to the drawing and addressed a few other things. Thoughts?

 

[Wootonius]

I'm a little biased, but I agree. Just because the Pi *can* do it doesn't mean it's a good idea. Anyone who has used BrewPi or Fermentrack has run into a case where the UI is no longer working (the Pi) but the Arduino or ESP8266 is happily controlling things in the background. A computer is not a controller.

You can pull information into CBPi I would imagine, and push settings to the controllers, but using a Pi for the actual control is no bueno IMHO.

Thanks for the feedback guys! I guess it wouldn't be that difficult to do a separate system for the Fermentation. Just a smaller box without the need for 240V, which is nice... I'll check into those two options with an Arduino.
I had found some threads where they were using the Arduino as a simple controller initially, but then I stumbled across the RPi stuff. RPi seemed to be the newer and more flexible solution with more potential functionality.

 

[LBussy]

RPi is definitely easier for people who are not programming in C++. The good news is, these temp control projects do not require you to work with the actual firmware. Have a look at the link in my sig, also look at Fermentrack. Either will meet your needs.

 

[papacap]

Ok, I've added the ULN to the drawing and addressed a few other things. Thoughts?

It all looks good to me. The only thing I saw is when it come to the thermometer be sure the resistor is between the data and 5v pins. You have the resistor in the right place with reference to the pi but the wire colors are slightly confusing. Generally the data pin is number 2 and marked yellow on a ds18b20. Gnd is pin 1 marked black and vcc is 3 marked red. Although a 2.2k resistor will probably work I'd recommend using a 4.7k as the manufacturer specifies. Its a very common value and shouldn't be any harder to find.

 

[LBussy]

4.7k resistors are for 5v, you will want 2k2 for 3v (devoid of other factors).

 

[jangevaa]

Hey guys, I've been on here and in the Electric Brewery section looking at wiring designs for several months. I've decided to go with RPi and it seems like CBPi is the best supported open source solution, so I'm ready to pull the trigger on a CBPi brew controller. I've been working on my parts list and drawing, but I'm a little confused about how to bring it all together.

• I've bought an RPi 4B. Will any GPIO breakout HAT work? This one seems pretty straightforward: Amazon.com
• I'm trying to blend the safety of a mechanical system (ala The Electric Brewery) with the GUI control of a computer based controller. To that end, I've tried to copy some of Doug's drawings, while replacing the PID with the RPi (using the CBPi Wiring drawing attached in this thread and here). See my first attempt at combining this attached.
• I'm having trouble understanding how I hook the temp probes in and the pump (do I need a relay? How would that wire up?).
• I'm not entirely sure I have the element/SSR hooked up right for this.

Sorry for the noob questions here. This is my first RPi and my first control panel, but I'm looking forward to taking my brewing to the next level. I really appreciate the help!!

Nice diagram
-I'd prefer to have the SSR after the contactor, and probably have another LED indicator tied to it to indicate things are live.
-SSR control circuit is not correct, should go to an available GPIO on RPi and DC Ground on RPi. DC GND is not the same as AC GND
-You'll need a pull up resistor for multiple DS18B20 temperature probes.
-May be better on the diagram to use different colours for DC +/-/GND from AC L1/L2/GND
-I prefer to have the pi not impacted by the master power switch, and have a separate small switch for it, don't need a relay or anything.
-If you haven't bought your pumps already you may be able to keep things a little simpler by leaving the 120v circuits out. A lot of pumps have 240v available.

edit: sorry HBT notifications can be confusing, I thought this was the last post in the thread and I see you've already got a bunch of help

 

[Wootonius]

It all looks good to me. The only thing I saw is when it come to the thermometer be sure the resistor is between the data and 5v pins. You have the resistor in the right place with reference to the pi but the wire colors are slightly confusing. Generally the data pin is number 2 and marked yellow on a ds18b20. Gnd is pin 1 marked black and vcc is 3 marked red.

I've corrected the wire colors and labeled things better. Hopefully it is more clear below. I added the DS to the drawing with the actual wire colors from the Auber web page. I figure all the wiring in the panel should be as uniform as possible.

Nice diagram
-I'd prefer to have the SSR after the contactor, and probably have another LED indicator tied to it to indicate things are live.
-SSR control circuit is not correct, should go to an available GPIO on RPi and DC Ground on RPi. DC GND is not the same as AC GND

Thanks jangevaa, I certainly don't mind the additional eyes and brainpower here! I'm truly grateful for all the help here on HBT!
Where would I put the SSR/Element fire LED?
The SSR is being triggered by 5VDC via the 3.3V from the Pi through the ULN. However, your comment got me looking closer at my diagram and I'm noticing my contactor is missing the other side of the signal connection (A1)...

Its possible that there are ways to wire the uln that I am not familiar with but mine is wired differently. Essentially I have the ssr+ connected directly to the +5v supply (or 5v on rpi). Then the ssr- goes to the output pin of the uln. When 3v is applied to the input pin. Current will flow through the uln output pin and out the uln gnd pin which should also be connected directly to the 5v ground reference (or gnd on rpi). The uln com pin should be at 5v for it to function properly. This essentially uses the uln as a relay controlling the return current from the ssr. The beauty of this layout is it let's you run the ssr with 5v I stead of 3v using only a 3v signal from the pi.

...and now I'm wondering about the ULN and Contactor combo which handles the SSR/Element firing. How do I connect in that other side of the contactor signal (A1), especially if I'm moving it to the other side of the SSR?

-May be better on the diagram to use different colours for DC +/-/GND from AC L1/L2/GND

Noted and corrected, thanks! Is it more clear below?

-I prefer to have the pi not impacted by the master power switch, and have a separate small switch for it, don't need a relay or anything.
-If you haven't bought your pumps already you may be able to keep things a little simpler by leaving the 120v circuits out. A lot of pumps have 240v available.

This does make sense to me. I added a simple switch to the V+ feed to the Pi from the DC Power Supply. I also moved the AC L1 feed to the DC power supply to the main power contactor input side. Do I need a fuse or something there?
I'm starting simple with my pumps. I already have a Ferroday 110V pump with a switch built into the power cord. Short term, I'll run that manually via that switch, and once I've got the element control right, I'll add in pump control.

It feels like I'm getting close here...

 

[jangevaa]

These revisions look good to me @Wootonius!

 

[papacap]

...and now I'm wondering about the ULN and Contactor combo which handles the SSR/Element firing. How do I connect in that other side of the contactor signal (A1), especially if I'm moving it to the other side of the SSR?

As far as having the contactor before or after the ssr I am not aware of any advantage between the two (but i would be curious to learn if there is). Personally, I have the contactor as the last device before the element outlet. Regardless of where you place it, the other side of the contactor coil depends on the contactor. I assume it is a 120v coil because you have it hooked up to the neutral phase. If that is the case then you want to connect the other end of it to a switch that switches one of the live phases. Once again I'd recommend using a 3-position switch so that when you add another ssr and element you can toggle between the two by switching which contactor is active (as in The Electric Brewery design).

I added a simple switch to the V+ feed to the Pi from the DC Power Supply. I also moved the AC L1 feed to the DC power supply to the main power contactor input side. Do I need a fuse or something there?

A slightly better design would be to place the switch you mention directly after the 5v supply so that you also power off the ssrs, uln, etc. (edit: upon further inspection I see you are powering the uln and ssrs through the 5v and gnd pi pins so what I suggested is unnecessary. I have those powered directly from the supply with the only connection to the pi being the uln input pin.) I am also now seeing that it looks like you are powering the pi via GPOIO pins. This is definitely not recommended. The pi has built-in protections but only for its usb-C power connector. You should get a usbC power cable and connect that to your 5v supply (or swicth after the supply) and use it to power the pi.

My design is very similar and I also put the 5v powers supply upstream of my master power switch. I found that after doing that and using the relay module for pumps that there is actually no longer a purpose to the master power contactor. I still have it in there but if I did another build I would exclude it and just rely on the element selector switch as my master.

As for protection, if you are using a 5v supply it should have a fuse or other protection built-in.

EDIT:

Where would I put the SSR/Element fire LED?

This depends on the LED you are using. The simplest option is to use a 240V LED and connect it right before the outlet across the 2 live phases (240V). If you have the contactor after the ssr, place it across the contactor output, if you have the SSR last then place it across the SSR output. I initially tried to use a 120V led across 1 phase and the neutral bus but this did not work because it will always illuminate when the contactor is active because the element is charged with one live phase even if current is not flowing (because the ssr only breaks one phase).

 

[Wootonius]

A slightly better design would be to place the switch you mention directly after the 5v supply so that you also power off the ssrs, uln, etc. (edit: upon further inspection I see you are powering the uln and ssrs through the 5v and gnd pi pins so what I suggested is unnecessary. I have those powered directly from the supply with the only connection to the pi being the uln input pin.) I am also now seeing that it looks like you are powering the pi via GPOIO pins. This is definitely not recommended. The pi has built-in protections but only for its usb-C power connector. You should get a usbC power cable and connect that to your 5v supply (or swicth after the supply) and use it to power the pi.

As for protection, if you are using a 5v supply it should have a fuse or other protection built-in.

Are you saying that you would use the USB-C cable plugged into a USB power supply (wall wart)? Since this is inside the panel, did you add an outlet inside for it to plug into? Or are you using some type of usb c breakout cable to get the 5VDC from the DIN Power Supply? I found one on Amazon that looks promising...
I'm using the Mean Well MDR-20-5, 5VDC 3A
https://www.meanwell.co.uk/assets/pdf/MDR-20-spec.pdfIt says it has short circuit, over voltage, overload protection built in. I would think it would have better protections than a wall wart, but maybe I'm misunderstanding.
Thanks again!

 

[papacap]

Are you saying that you would use the USB-C cable plugged into a USB power supply (wall wart)? Since this is inside the panel, did you add an outlet inside for it to plug into? Or are you using some type of usb c breakout cable to get the 5VDC from the DIN Power Supply?

Basically, take any old USBC cable and cut off the USB end of it. Strip the red and black leads and connect them to the 5v supply you were going to use (that Mean Well one is a good choice). Then plug the USB-C end into the pi for power. Essentially exactly what you were planning just via the pi USB-C port instead of the GPIO pins. The Mean Well powers supply works the same as a wall wart in this case. The supply has its own protections (to deal with surges in the mains and limit current to 3A) but it is recommended not to power the pi via GPIO because it has no ability to regulate its current through there. If something were to short on the pi or other GPIO it could melt (the supply could deliver 3A through the GPIO which would be very bad). Its USB-C port has a resettable fuse that offers an additional level of protection.

 

[Wootonius]

Here is the latest. I think I've got something I can build!
I still open to suggestions, but I'm going to go ahead and order what I know I'll need. Thanks to all that helped so far. I appreciate everyone's time and above all, patience!

 

[Lalo_uy]

It all looks good to me. The only thing I saw is when it come to the thermometer be sure the resistor is between the data and 5v pins. You have the resistor in the right place with reference to the pi but the wire colors are slightly confusing. Generally the data pin is number 2 and marked yellow on a ds18b20. Gnd is pin 1 marked black and vcc is 3 marked red. Although a 2.2k resistor will probably work I'd recommend using a 4.7k as the manufacturer specifies. Its a very common value and shouldn't be any harder to find.

The pullup resistor need to go to 3.3v, since the gpio will break if pulled to 5v.
As show in the picture is ok. The DS18b20 are powered with 3v, that is near the lower limit.
I prefer to put Ds18b20 vcc to 5v and keep only the pullup to 3.3v.

 

[papacap]

The pullup resistor need to go to 3.3v, since the gpio will break if pulled to 5v.
As show in the picture is ok. The DS18b20 are powered with 3v, that is near the lower limit.
I prefer to put Ds18b20 vcc to 5v and keep only the pullup to 3.3v.

Somewhat confused by what you saying but it should be fine to pullup to 5v or 3v as long as you use the correct resistor value.
The resistor just needs to limit the current to about 1 mA and the sensor will work fine. I have heard people say you should not apply 5v logic to the GPIO pins but many people seem to use the ds18b20 with data line pulled to 5v without issues. If there is any report of this actually causing damage I would love to know as I currently have mine wired that way. Given the internal GPIO resistors, won't any current be in the microAmp range?

 

[day_trippr]

Anecdotal testimonials aside, why risk problems when the proper solution is literally a pin or two away?
3.3V IO cells have input clamping diodes referenced to the 3.3V rail. They're good for about .7 volts of overshoot and are there to limit signal integrity issues leading to overshoot, so pulling an input to 5V is going to unnecessarily stress the input cell.

I mean, there's the right way, and then there's "this guy on the internet said nothing died [yet]"

Cheers!

 

[papacap]

Well in my case its a matter of rebuilding my prototype board (doesn't currently have a 3V rail) which is a decent chunk of work. I'm trying to get a sense of what risk I'm dealing with because I would certainly prefer rebuilding over burning my pi. If it does go bad will it just fry that one gpio or the whole cpu?

 

[day_trippr]

Typically, just the specific IO cell is subject to failure due to essentially static over-voltage exposure.

If you are using an RPi or ESP, there will be a 3.3V regulated source available, and for at least a string of ds18b20s the pull-up current is quite small. Even a flying lead to a dead-bugged resistor would be fine and avoid an obvious risk...

Cheers!

 

[Lalo_uy]

I could not find any datasheet for rpi4 cpu, but here is the one of rpi3+

Raspberry Pi 3+ Module
There on page 12 you see absolute maximum of 4.1v
Instead of redesing the board just put the pullup in the connector between pins 1 and 7.