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mission:resources:picoreflow [2015/01/29 09:40]
chrono [Software]
mission:resources:picoreflow [2021/08/30 22:25] (current)
chrono [Simulation]
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 More and more semiconductors are produced in packages (the chip's case) which have become impossible to hand solder with a solder iron. The switch from through-hole (THT) to surface mount technology (SMT) has actually made hand soldering much easier (although still many believe the opposite to be true) but now we are faced with BGA and other packaging forms which only have contacts on the bottom of the chip.  More and more semiconductors are produced in packages (the chip's case) which have become impossible to hand solder with a solder iron. The switch from through-hole (THT) to surface mount technology (SMT) has actually made hand soldering much easier (although still many believe the opposite to be true) but now we are faced with BGA and other packaging forms which only have contacts on the bottom of the chip. 
  
-In order to be able to work with these chips, a reflow solder process is needed. So we've built our own DIY reflow oven, using a Raspberry Pi as a universal, web enabled, PID Reflow Oven Controller driving a convectional hot air oven originally designated for gastronomy/bakery purposes. Since it's all open-source you may also use it to build the world's most sophisticated pizza oven controller and experiment with temperature curves for fresh/frozen pizza :)+In order to be able to work with these chips, a reflow solder process is needed. So we've built our own DIY reflow oven, using a Raspberry Pi as a universal, web enabled, PID Reflow Oven Controller driving a convectional hot air oven originally designated for gastronomy/bakery purposes.  
 + 
 +Since it's all open-source you may also use it to build a kiln controller, the world's most sophisticated pizza oven controller and experiment with temperature curves for fresh/frozen pizza and has also been reported to be used in other lab/production processing systems and autonomous climate testing.
  
 <WRAP round alert> <WRAP round alert>
Line 85: Line 87:
  
 ==== Heating ==== ==== Heating ====
 +
 +=== Load Wiring ===
 +
 +{{:mission:resources:picoreflow-ssr-load-connection.png|}}
 +
 +=== Signal Wiring ===
  
 SSR connected to P1-23 SSR connected to P1-23
  
 +^ PullDown Connection (default) ^ PullUp Connection (alternative) ^
 +| {{:mission:resources:picoreflow-ssr-signal-pulldown-connection.png?320|}} | {{:mission:resources:picoreflow-ssr-signal-pullup-connection.png?320|}} |
 +
 +
 +The default configuration has historically been to use the PullDown config, which results in an inverted control logic: When you pull GPIO23 low, the heater is switched on and when you pull GPIO23 high, the heater is switched off. 
 +
 +<WRAP round important>
 +**Please keep in mind that you'll have to have some script/code in your setup that makes sure that GPIO23 is pulled high as soon as the system has booted** (to be sure the heater is off) or change your setup to PullUp configuration instead, if you don't want to worry/bother.
 +</WRAP>
 ==== Cooling ==== ==== Cooling ====
  
Line 99: Line 116:
 ===== Software ===== ===== Software =====
  
-The picoReflow server is based on Python with only a few other dependencies. It was developed with foucs on Reflow purposes but as more and more people stumbled upon this project and are creatively using it for completely different (although related) use-caseswe'd like to push further development of this project into a more generalized next-generation FOSS PID controller which can be used for many more use-cases than just building a Reflow oven. If you're a Python/JavaScript developer and want to joinplease [[contact:start|contact us]], we have all the infrastructure we need to do remote hackathons as well.+<WRAP round info> 
 +**Although picoReflow seems to become ever more popular and is working fine, it has its limits in terms of flexibility and use-case adaptability: It was only modeled and catered to the parameters and constraints of a reflow soldering process.**\\ 
 +  
 +With the help of a lot of people giving feedback and using picoReflow in the wildit was easy to see that a more flexible, modular and powerful approach would be needed to become a fully autonomousmulti-module governing/monitoring bot for any DIY appliance. She calls herself [[https://github.com/apollo-ng/governess|governess]] but she's still not ready for anything yet but it's progress. More appliance/module/driver/task modelling/linking will be required. It has to be totally data-driven in order to offer any useful flexibility.
  
 +With the switch to angular/ionic2 almost everything that had been done in angular1 in the meantime was useless and had to be re-implemented, a few concepts prevailed though and a rough client mock is the only thing that has been done so far while waiting for angular/ionic2 crowd to settle a bit into stable before cracking the tough nuts. So far a lot of the desired features are already mocked or in the process of implementation but the server will need to be a complete re-implementation as well. So, as long as it's only me I can only do so much in this time. Any helping hacker brain with python and/or angular2/ionic2 skills or the will to acquire them (learning by doing) is invited to join and help, we have all the tools & infrastructure needed to do remote hackathons as well.
  
 +  * https://github.com/apollo-ng/governess/milestones/governess-1.0.0
 +  * Rough Dev-Notes on https://apollo.open-resource.org/pad/picopid
 +  * Make sure to check-in again and/or subscribe the [[https://apollo.open-resource.org/mission:log:feed|RSS Feed]]
 +
 +**Screenshots of new the interface (Profile-Editor)**
 +
 +{{:mission:resources:governess-profile-editor-1.jpg?250|Profile Editor: Temperature Curve}}
 +{{:mission:resources:governess-profile-editor-2.jpg?290|Profile Editor: Circulcator Curve}}
 +</WRAP>
 ==== Dependencies ==== ==== Dependencies ====
  
Line 186: Line 216:
  
 === Calculation === === Calculation ===
-Every <x 14>\Delta t</x> the following calculations are performed:+Every $\Delta tthe following calculations are performed:
  
  
 Thermal energy flowing into the heating element: Thermal energy flowing into the heating element:
  
-<x 14> +Q_h = P_heat * \Delta t $
-Q_h = P_heat * \Delta t +
-</x>+
  
 Temperature change of heating element by heating: Temperature change of heating element by heating:
  
-<x 14> +\Delta T_h1 = Q_h / C_heat $
-\Delta T_h1 = Q_h / C_heat +
-</x> +
  
 Temperature change between heating element and oven: Temperature change between heating element and oven:
  
-<x 14> +P_ho = (T_h - T) / R_ho $
-P_ho = (T_h - T) / R_ho +
-</x>+
  
-<x 14> +\Delta T_1 = (P_ho / C_oven) * \Delta t $
-\Delta T_1 = (P_ho / C_oven) * \Delta t +
-</x>+
  
-<x 14> +\Delta T_h2 = - (P_ho / C_oven) * \Delta t $
-\Delta T_h2 = - (P_ho / C_oven) * \Delta t +
-</x>+
  
 Temperature change between oven and environment Temperature change between oven and environment
  
-<x 14> +P_oe = (T - T_env) / R_oe $ 
-P_oe = (T - T_env) / R_oe + 
-</x>+$ \Delta T_2 = - (P_oe C_oven) * \Delta t $ 
 + 
 +Temperature of oven and heating element at this time-step: 
 + 
 +$ T = T_old + \Delta T_1 + \Delta T_2 $ 
 + 
 +$ T_h = T_h_old + \Delta T_h1 + \Delta T_h2 $ 
 + 
 + 
 +===== picoReflow in the Wild ===== 
 + 
 +This project already has inspired a couple of people who are using this concept and free software stack for their own purposes: 
 + 
 +==== DIY Reflow Toaster ==== 
 + 
 +{{:mission:resources:reflow_toaster_by_cube47_pcb.png|Reflow Toaster HW Controller PCB of cube37 }} 
 +{{ :mission:resources:reflow_toaster_by_cube47_block_diagram.png|Reflow Toaster block-diagram of cube37}} 
 + 
 +  * http://www.cube37.com/projects/reflow_toaster/design 
 +  * The domain seems to have gone offline, there is [[https://web.archive.org/web/20150814140751/http://www.cube37.com/projects/reflow_toaster/design|a snapshot on archive.org]] 
 + 
 +==== Ararpi Reflow Oven ==== 
 + 
 +{{:mission:resources:ararpi-reflow-oven-with-picoreflow-hardware.jpg|ararpi-reflow-oven-with-picoreflow-hardware}} 
 + 
 +http://ararpi.simplesite.com 
 + 
 +==== Moore Bros Composite Oven ====   
 + 
 +{{:mission:resources:moore-bros-composite-oven-with-picoreflow-hardware.jpg|moore-bros-composite-oven-with-picoreflow-hardware}} 
 + 
 +A custom built oven to bake carbon composite parts.  
  
-<x 14> +==== WiFi/Raspberry Pi pottery kiln controller ====  
-\Delta T_2 - (P_oe C_oven) * \Delta t +
-</x>+
  
-Temperature of oven and heating element at this timestep:+{{:mission:resources:kilnrunning.jpg|}}
  
-<x 14> +http://succulentceramics.com/2016/10/07/wifiraspberry-kiln-controller/
-T = T_old + \Delta T_1 + \Delta T_2 +
-</x>+
  
-<x 14> 
-T_h = T_h_old + \Delta T_h1 + \Delta T_h2 
-</x> 
  
 {{tag>research lab reflow oven pid controller raspberry pi picofab software hardware}} {{tag>research lab reflow oven pid controller raspberry pi picofab software hardware}}