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mission:resources:picoreflow [2016/09/21 09:20]
chrono [picoReflow]
mission:resources:picoreflow [2021/08/30 22:25] (current)
chrono [Simulation]
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 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.  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 and has also been reported to be used in other lab/production processing systems and autonomous climate testing applications.+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>
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 ==== 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 ====
  
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 === 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>+
  
-<x 14> +\Delta T_2 = - (P_oe / C_oven) * \Delta t $
-\Delta T_2 = - (P_oe / C_oven) * \Delta t +
-</x>+
  
-Temperature of oven and heating element at this timestep:+Temperature of oven and heating element at this time-step:
  
-<x 14> +T = T_old + \Delta T_1 + \Delta T_2 $
-T = T_old + \Delta T_1 + \Delta T_2 +
-</x>+
  
-<x 14> +T_h = T_h_old + \Delta T_h1 + \Delta T_h2 $
-T_h = T_h_old + \Delta T_h1 + \Delta T_h2 +
-</x>+
  
  
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 A custom built oven to bake carbon composite parts.   A custom built oven to bake carbon composite parts.  
 +
 +==== WiFi/Raspberry Pi pottery kiln controller ====  
 +
 +{{:mission:resources:kilnrunning.jpg|}}
 +
 +http://succulentceramics.com/2016/10/07/wifiraspberry-kiln-controller/
 +
  
 {{tag>research lab reflow oven pid controller raspberry pi picofab software hardware}} {{tag>research lab reflow oven pid controller raspberry pi picofab software hardware}}