### DESCRIPTION

OpenReflow aimed to be a simple board to convert low-cost toaster ovens into accurate soldering tools.

### NOT RECOMMENDED FOR NEW BUILDS!

Please note that for the temperature sensor, I used a voltage divider to read a PT100 element. This makes it necessary to manually calibrate, and even then it wouldn't be as accurate as using a proper RTC reading chip (i.e. MAX31865).

Also the "zero crossing" detector wasn't really necessary for the small wattage and slow pulses involved (at most 1500W at 1Hz). It just adds complexity and makes the board more dangerous by mixing digital and live tracks.

In the end I think it would be more simple to just flash a standard Sonoff switch and wire an external temperature sensor module.

### TECHNICAL DETAILS / COMPONENTS

Compared to other solutions, these are the advantages of OpenReflow:

- The board already incorporates an AC-DC converter, greatly simplifying installation (does not need additional power supplies).

- It uses a low cost mechanical relay, combined with a mains zero-cross detector. The relay is switched ONLY when the mains AC line is crossing zero; this reduces the wear of electric contacts and saves the cost of an actual SSR.

- It has a single processor: a WiFi-enabled ESP8266.

- Temperature sensing is done directly with a Pt100 element that interfaces an ADC.

The final goal of the project is to have a mobile phone interface, so the oven's user can connect to its access point ("OpenReflow" by default) and adjust the soldering profiles easily.

All of this while keeping everyting nice and tidy within the original enclosure of the toaster oven.

### LEARN / TOPIC / BUILD INSTRUCTIONS

At the moment the project is experimental, and will be fully docummented with a BOM after testing it thoroughly.

Thank you for reading! Please let us know your thougths in the comments.

Also, if you like our project, please click on the "appreciate" button above, it really helps!

PS: It will be very meta to bake more OpenReflow boards in the OpenReflow oven itself... :-)