It has been pretty quiet on the blog lately. We are busy testing all our designs and perform redesign and corrections on the prototypes. There’s a pile of yet to be released boards too. One of the current project we are working on is an Arduino based reflow oven controller. We have been using SMT based components for a long time and hand soldering them for bigger batch of boards seems to be rather a long and tedious process. We know there’s so many small maker like us facing the same problem like us. Sending the boards out for assembly means high volume and higher cost for each product. After all, we are not planning to be viral, 🙂
The reflow oven controller is designed as a shield to be stacked on an Arduino (Uno and Duemilanove). Some of the reflow oven controller features:
- MAX6675 K thermocouple interface with terminal block connection.
- Solid State Relay (SSR) connection header to control an oven.
- 2 push button with hardware based debounce circuitry (you don’t have to implement software debounce).
- 2 LED (red and green) for visual indication.
- Buzzer for audio indication.
- 8×2 character LCD with contrast adjust and yellow back light (we’ll get the blue back light for final design!) for display.
- Reset push button.
- Dimension – 55.88 mm x 53.34 mm (no shorting with USB connector and DC jack on Arduino board).
We have tested all the necessary peripheral and now working on the reflow characteristic of our oven. Our initial plan is to arbitrarily control the oven without any PID control algorithm before implementing a more accurate PID control on the system. We are using a 800 W oven with top and bottom heating element shown below. We have so far manage to test the oven up to 260 ℃. We just love the size of the oven as all the PCB that we have worked on so far (either single or panel) fits into the oven nicely. The glass door is a bonus that allows us to observe the reflow process.
We’ll be releasing the hardware design and related firmware once it is finalized based on CC BY-SA 3.0. This reflow oven controller will have it own project folder in this blog for easier access and organization. The final version of the design will also be on sale at our website once we complete all the testing.
Here are a couple more images of the reflow oven controller: