Masterbuilt Build Thread (PID, WIFI, Android)

[velorider562]

This is a work in progress build thread inspired by a desire to create a better smoker and all the mod thread on this forum….

Purchased an unused Masterbuild 30" Electric smoker on OfferUp for $60 for this build project. I'll likely get feedback on this thread saying I could have bought X to solve Y and that's completely true. However, buying W, X, Y, and Z to solve A,B, C, and D ends up creating a frankenstein. Additionally, I really enjoy learning new skills and building things that look like I didn't build it. The following is a build thread of gutting a Masterbuild 30" electric smoker and rebuilding it from the ground up.

Objectives of the rebuild is to fix the temperature fluctuation, add wifi, Android app, multiple meat probes, and automatic temperature adjustments for different phases of the smoking and accomplish this without the finished project looking like a frankenstein smoker.

A lot of the knowledge of how the Masterbuild smoker works was compiled from this forum.

My idea was to replace the control board on top of the smoker with a customer ESP32 based control board that plugs into the existing wire harness for power, smoker temperature and heating element control. I also replaced the power board underneath the smoker with a new board that has a solid state relay and provides 3.3v dc instead of a mechanical relay and 5v dc of the original. Solid state relay seems like a better choice given the frequency of on/off switch PID could generate.

After some tweaking here is the temperature graph of the smoker, measured every 5 seconds. The red line was the target tempature of 225, the blue is the actual tempature.

Custom power board, install in the smoker where the original power board was installed. The solid state relay, out frame on the left. The black connector with the red, black, white, and blue is the factory harness on the plugs into the control board on top.

Prototype ESP32 based control board, plugged into the existing harness. After reverse engineering the original board and lots of trail and error the temperature reading matches within 1 degree of a counter top meat probe sensor we used for xmas roast :)

Modified Mailbox Mod Mod

I really liked the theory behind the mailbox mod.. Instead of a mailbox I purchased a cheap “safe” off Amazon. The word “safe” is in quotes because it’s basically just a 16 gauge steel box. Removed the lock mechanism and epoxy steel putty’ed the holes. Purchased some 3’ ABS plastic flanged and aluminum semi-rigid flex duct.

Today, I finally picked up a Harbor Freight tool stand and assembled everything. Need to resize the wood top and mount the smoke box underneath.

Next steps:
Design the PCB for the control board and order it from oshpark.com.
3D print an enclosure for the control board that mounts into the existing mount points on top of the smoker.
Develop an Android base app that allows me to control and monitor the smoker
Create cooking “recipes” that adjust temperature when certain meat temperatures are achieved.


Current Build Sheet:
Masterbuilt Smoker (unused on offerup) $60
Customer Power Board $10.43
Solid State Relay $6.30
Safe (Mailbox mod) $54.88
Harbor Freight Tool Stand: $36.54

 

[dr k]

I got a free Mes 30 on FB Marketplace a few years ago. I could hear the relay click after entering time and temp the first test but no heat. A power cord with lugs directly terminated to the element and the ground wire tightened around one of the access screws to the body was instantly heating so I figured check the thermal snap disk safety switch. I cut an access in the back of the smoker and a lug was disintegrated with just a bare wire, so wire nutted the wires to bypass the switch and use my multi probe digital therm with the pit probe set to a range 145-290 for an alert if the smoker is cold or on fire. These switches seem to fail at the worst time like a night long smoke. You may want to make an access before it fails to get to it and bypass to finish the smoke. I like to bring inside the Mes controller which I don't have heat fluctuation issues with and is a great little smoker and bring in the Auber PID plug and play as well from the Mes 40 in between smokes. These controllers without conformal coatings on PCBs mostly with a hole in the bottom gets condensing water vapor and smoke inside them when left outside and cool from being warm ontop of the smoker and coorode/short traces. I like to bring them inside the a/c asap when they are still warm. One stock controller the rf remote light button shut off the smoker. Another same model controller the same rf remote meat probe button shut off the smoker and a free replacement controller from Masterbuilt has been fine for three years with the same rf remote, getting it out of humidy when warm before it could condense. Now i can keep the controllers farther away from the vent smoke and is a quick disconnect.

The auto switching based on probe temp to a different smoker temp sounds interesting but I don't run my smoker unless someone is home, checking on it, mainly me so I just bump up the PID manually when the probe temp tells me to so no automation for me. The Auber has six stages to set in minutes till the next stage temp kicks in but your temp of food to change smoker temp is better. I changed my program mode to the single step so no minutes to enter, it just stays at that temp till you change it. I was sick of setting 3,000 minutes so it wouldn't shut off on a single stage brisket, pork butt etc. Good luck with all the automation if you really need it.

 

[tallbm]

This is a work in progress build thread inspired by a desire to create a better smoker and all the mod thread on this forum….

Purchased an unused Masterbuild 30" Electric smoker on OfferUp for $60 for this build project. I'll likely get feedback on this thread saying I could have bought X to solve Y and that's completely true. However, buying W, X, Y, and Z to solve A,B, C, and D ends up creating a frankenstein. Additionally, I really enjoy learning new skills and building things that look like I didn't build it. The following is a build thread of gutting a Masterbuild 30" electric smoker and rebuilding it from the ground up.

Objectives of the rebuild is to fix the temperature fluctuation, add wifi, Android app, multiple meat probes, and automatic temperature adjustments for different phases of the smoking and accomplish this without the finished project looking like a frankenstein smoker.

A lot of the knowledge of how the Masterbuild smoker works was compiled from this forum.

My idea was to replace the control board on top of the smoker with a customer ESP32 based control board that plugs into the existing wire harness for power, smoker temperature and heating element control. I also replaced the power board underneath the smoker with a new board that has a solid state relay and provides 3.3v dc instead of a mechanical relay and 5v dc of the original. Solid state relay seems like a better choice given the frequency of on/off switch PID could generate.

After some tweaking here is the temperature graph of the smoker, measured every 5 seconds. The red line was the target tempature of 225, the blue is the actual tempature.

View attachment 659263



Custom power board, install in the smoker where the original power board was installed. The solid state relay, out frame on the left. The black connector with the red, black, white, and blue is the factory harness on the plugs into the control board on top.

View attachment 659265


Prototype ESP32 based control board, plugged into the existing harness. After reverse engineering the original board and lots of trail and error the temperature reading matches within 1 degree of a counter top meat probe sensor we used for xmas roast :)

View attachment 659266



Modified Mailbox Mod Mod

I really liked the theory behind the mailbox mod.. Instead of a mailbox I purchased a cheap “safe” off Amazon. The word “safe” is in quotes because it’s basically just a 16 gauge steel box. Removed the lock mechanism and epoxy steel putty’ed the holes. Purchased some 3’ ABS plastic flanged and aluminum semi-rigid flex duct.

View attachment 659267



Today, I finally picked up a Harbor Freight tool stand and assembled everything. Need to resize the wood top and mount the smoke box underneath.

View attachment 659268


Next steps:
Design the PCB for the control board and order it from oshpark.com.
3D print an enclosure for the control board that mounts into the existing mount points on top of the smoker.
Develop an Android base app that allows me to control and monitor the smoker
Create cooking “recipes” that adjust temperature when certain meat temperatures are achieved.


Current Build Sheet:
Masterbuilt Smoker (unused on offerup) $60
Customer Power Board $10.43
Solid State Relay $6.30
Safe (Mailbox mod) $54.88
Harbor Freight Tool Stand: $36.54

Hi there and welcome!

Seems like a cool and really fun project!

I second dr k on cutting a panel in the back so you can access the safety rollout limit switch. The stock MES connectors are trash and that switch melts down and fails often due to the connectors corroding and causing resistance that then burns up the switch itself.
It's best to go ahead and cut the panel and swap the connectors and probably upgrade to a ceramic KSD301 switch (I use ones that go to 354F limit so I can do fast 325F skin on chicken smokes and not get rubber skin lol).

I am also think it's a good idea to make the top controller removeable so the elements and condensation doesn't ruin parts of your controller.

I use a HeaterMeter PID and live in TX. I think the humidity ruined the wifi portion of the pcb in the controller and wifi no longer works. Those parts are not exactly weather friendly so if you have an area to think and improve upon, this is definitely one to consider. Also my smoker is kept in a sealed plastic "shed" built for housing a pair of trash cans so it keeps the elements directly off the smoker and controller at all times but this still happened again probably due to humidity and condensation.

The HeaterMeter documentation may give you a good parts list or at least ideas on what you may want to do with the controller and wifi. They used a Raspberry Pi3 B+ I believe and also they have an android app where I think the app source code may be in github but can't remember, it's been a while since I fooled with all this.

Here is my post on getting my HeaterMeter going and things I found that the documentation didnt get correct like the need for at least a 3amp power supply instead of the recommended 1amp, etc.

HeaterMeter Controller, with Wifi, and Electric Smoker (MES40) Mod in Detail

Want to know how to setup the HeaterMeter PID Controller with Wifi to work with the MES? Here you go :) Table of Contents Overview HeaterMeter Mod Design MES Rewired - just mention don't go into detail HeaterMeter Based Controller Box Wiring and Diagrams HeaterMeter Setup Common Setup...

www.smokingmeatforums.com

I totally understand the enjoyment of the project and look forward to seeing what you come up with. Also know that I have no intention of trying to sway you from creating something new in favor of something that already exists. This work all sounds fantastic to me! :D

 

[velorider562]

Thanks for the information on the corrosion and upgraded ceramic safety switch. I'll definitely look into it.

I'm also going to search GitHub for the app you mentioned. Modify and existing app will save a lot of time.

Today was another rain day so I sat with the wife and watched moves and designed the wifi control pcb.

The next update won't be for a couple weeks while I wait for the fab shop to produce the pcb.

 

[pbk]

Sweet setup!

Did you end up ditching the built-in temperature probe? I see you used all four connectors when you were doing development on the breadboard, but on the circuit diagram it looks like the 2nd from the left connector pin (which on my smoker is the temp probe) it's unused.

I've got a similar setup on my 30". I'm using an ESP32 I had around to do PID control, but using standalone K-type thermocouples and the built-in relay. I use time proportioning control so I don't burn out the relay. I've been trying to figure out what settings to use for the built-in temperature probe. If you have any info on the circuitry for the probe or the temperature mapping, I'd love to hear it!

 

[tallbm]

Thanks for the information on the corrosion and upgraded ceramic safety switch. I'll definitely look into it.

I'm also going to search GitHub for the app you mentioned. Modify and existing app will save a lot of time.

Today was another rain day so I sat with the wife and watched moves and designed the wifi control pcb.


View attachment 659311


The next update won't be for a couple weeks while I wait for the fab shop to produce the pcb.

Here you go, this should save you some time looking for the source code :D

GitHub - colings/pitdroid: PitDroid - HeaterMeter Android app

PitDroid - HeaterMeter Android app. Contribute to colings/pitdroid development by creating an account on GitHub.

github.com

 

[velorider562]

Sweet setup!

Did you end up ditching the built-in temperature probe? I see you used all four connectors when you were doing development on the breadboard, but on the circuit diagram it looks like the 2nd from the left connector pin (which on my smoker is the temp probe) it's unused.

I've got a similar setup on my 30". I'm using an ESP32 I had around to do PID control, but using standalone K-type thermocouples and the built-in relay. I use time proportioning control so I don't burn out the relay. I've been trying to figure out what settings to use for the built-in temperature probe. If you have any info on the circuitry for the probe or the temperature mapping, I'd love to hear it!

I am using the built in temperature sensor. The connector you're referring, the pins order is non-standard. When I designed the power module board I messed up the pin order and so the pin order on the above control PCB is ordered incorrectly to match. I have since corrected the pin order on the power module board but have not ordered new boards. The built in temperature sensor is 3rd from the left.

The built in temperature sensor is powered from 5v DC from the power module under the smoker. The temperature sensor "Signal" wire then runs up to the top of the smoker. Since the ESP32 is 3.3v you can't read the 5v "signal" wire directly. This was one of the main reasons behind replacing the power module. I think with the correct resistor divider value you could get between 0 and 3.3v. The original control board also had caps to smooth the temperature sensor voltage. During testing I noticed more consistent reads with a 56pf cap. Looking at the PCB above follow pin 3 and you're see the cap and resistor.

I do have the Steinhart-Hart A/B/C coiffienents and am happy to share. I'll push everything to GitHub tomorrow sometime and post here the URL.

Hope this helps.

 

[tallbm]

I am using the built in temperature sensor. The connector you're referring, the pins order is non-standard. When I designed the power module board I messed up the pin order and so the pin order on the above control PCB is ordered incorrectly to match. I have since corrected the pin order on the power module board but have not ordered new boards. The built in temperature sensor is 3rd from the left.

The built in temperature sensor is powered from 5v DC from the power module under the smoker. The temperature sensor "Signal" wire then runs up to the top of the smoker. Since the ESP32 is 3.3v you can't read the 5v "signal" wire directly. This was one of the main reasons behind replacing the power module. I think with the correct resistor divider value you could get between 0 and 3.3v. The original control board also had caps to smooth the temperature sensor voltage. During testing I noticed more consistent reads with a 56pf cap. Looking at the PCB above follow pin 3 and you're see the cap and resistor.

I do have the Steinhart-Hart A/B/C coiffienents and am happy to share. I'll push everything to GitHub tomorrow sometime and post here the URL.

Hope this helps.

FYI, the MES units are notorious for never reading temp very well. Not sure if it is the probes they use (meat and smoker probes are both off) or something else in the mix.

Figured I would mention this in the case that it is the probe itself. If it is then you may want to swap the existing probe for a better one since you are repurposing the existing probe and wiring.

I'm interested to see what you find with it's stock probe readings so we finally may know if it's an issue with the probes or their other components. Again, bot the smoker and meat probes are notoriously off by quite a bit.

 

[normanaj]

Cool thread but way beyond my electrical ability! I was intimidated just adding an Auber PID but it happened.

 

[velorider562]

tallbm I have not noticed issues with the temperature sensor. I used a stand alone meat probe and temperatures where within a degree or 2 of each other. Could be the factory controller or firmware causing issues. Both are involved in getting good reads. I tuned the coefficients for SH algorithm in the firmware for 150 to 250 range. This ensures the temperature sensor is most accurate within this range.

 

[tallbm]

tallbm I have not noticed issues with the temperature sensor. I used a stand alone meat probe and temperatures where within a degree or 2 of each other. Could be the factory controller or firmware causing issues. Both are involved in getting good reads. I tuned the coefficients for SH algorithm in the firmware for 150 to 250 range. This ensures the temperature sensor is most accurate within this range.

I don't doubt one bit the factory controller or firmware is attempting to do some "magic" and they simply just don't care that it is bad. Hell to my knowledge the Bluetooth feature still doesn't work and really never has and they keep releasing the same crappy bluetooth versions lol.

 

[velorider562]

P pbk Here is the github repo with the firmware and eagle pcb files. This project is still very much under developement.

GitHub - jpetrocik/masterbuilt_smoker

Contribute to jpetrocik/masterbuilt_smoker development by creating an account on GitHub.

github.com

 

[pbk]

P pbk Here is the github repo with the firmware and eagle pcb files. This project is still very much under developement.

GitHub - jpetrocik/masterbuilt_smoker

Contribute to jpetrocik/masterbuilt_smoker development by creating an account on GitHub.

github.com

Thanks!

 

[river100]

This is a work in progress build thread inspired by a desire to create a better smoker and all the mod thread on this forum….

Purchased an unused Masterbuild 30" Electric smoker on OfferUp for $60 for this build project. I'll likely get feedback on this thread saying I could have bought X to solve Y and that's completely true. However, buying W, X, Y, and Z to solve A,B, C, and D ends up creating a frankenstein. Additionally, I really enjoy learning new skills and building things that look like I didn't build it. The following is a build thread of gutting a Masterbuild 30" electric smoker and rebuilding it from the ground up.

Objectives of the rebuild is to fix the temperature fluctuation, add wifi, Android app, multiple meat probes, and automatic temperature adjustments for different phases of the smoking and accomplish this without the finished project looking like a frankenstein smoker.

A lot of the knowledge of how the Masterbuild smoker works was compiled from this forum.

My idea was to replace the control board on top of the smoker with a customer ESP32 based control board that plugs into the existing wire harness for power, smoker temperature and heating element control. I also replaced the power board underneath the smoker with a new board that has a solid state relay and provides 3.3v dc instead of a mechanical relay and 5v dc of the original. Solid state relay seems like a better choice given the frequency of on/off switch PID could generate.

After some tweaking here is the temperature graph of the smoker, measured every 5 seconds. The red line was the target tempature of 225, the blue is the actual tempature.

View attachment 659263



Custom power board, install in the smoker where the original power board was installed. The solid state relay, out frame on the left. The black connector with the red, black, white, and blue is the factory harness on the plugs into the control board on top.

View attachment 659265


Prototype ESP32 based control board, plugged into the existing harness. After reverse engineering the original board and lots of trail and error the temperature reading matches within 1 degree of a counter top meat probe sensor we used for xmas roast :)

View attachment 659266



Modified Mailbox Mod Mod

I really liked the theory behind the mailbox mod.. Instead of a mailbox I purchased a cheap “safe” off Amazon. The word “safe” is in quotes because it’s basically just a 16 gauge steel box. Removed the lock mechanism and epoxy steel putty’ed the holes. Purchased some 3’ ABS plastic flanged and aluminum semi-rigid flex duct.

View attachment 659267



Today, I finally picked up a Harbor Freight tool stand and assembled everything. Need to resize the wood top and mount the smoke box underneath.

View attachment 659268


Next steps:
Design the PCB for the control board and order it from oshpark.com.
3D print an enclosure for the control board that mounts into the existing mount points on top of the smoker.
Develop an Android base app that allows me to control and monitor the smoker
Create cooking “recipes” that adjust temperature when certain meat temperatures are achieved.


Current Build Sheet:
Masterbuilt Smoker (unused on offerup) $60
Customer Power Board $10.43
Solid State Relay $6.30
Safe (Mailbox mod) $54.88
Harbor Freight Tool Stand: $36.54

Very nice! I really like the graph. Would you mind listing the brand / model # of that ESP32 board? And of course I want to know what OS it uses. LOL, code would be nice too. :)
I rigged up a Temp graphing system for our chiller and cold storage at work but the sensing board I used only uses 1-wire digital sensors. I modified a guys script for XYMON that was running around the net years ago. I'm no programmer so for me it's simple hacks and mostly copy and paste.