Hobbybotics Reflow Controller
April 7, 2011
7 April 2011:
Wow, it has been ages since I actually posted something although I visit the site pretty much every day. I ain't (good slang term) making no excuses but, okay, I am making some excuses as I am in the military and I do work roughy 11 hours, 5 days a week (when I'm not traveling).
Of course this blog post is not my attempts at apologizing (as if anyone cared) but, is for me to post some progress on a project that I have been working on for quite some time (I swear that the news of the government possibly shutting down over the budget, that will leave me without a paycheck, has nothing to do with me finding time to actually post something).
The title says it all..it is a reflow controller that is a combination of a standalone device that can be manually controlled or computer operated through a C# interface. The idea is to interface some external electronics to an unmodified toaster oven and use it to reflow my circuit boards.
I won't bore you with all of the dirty details right now as I want to use this blog to post information until I have the project finalized. I like to provide as much detail as possible so that others may learn something and/or provide some feedback.
Here are a few pictures to tide you over:
I actually have three different versions of the controller with different feature sets. I will add pictures of the different version once I have them complete. All version of the controller use a MAX6675 thermocouple. Versions 1 and 2 both have a MAX3232 for RS232 communications with the PC and a connection for a FTDI breakout board if USB communications/power is prefered. Version 1 controller has a DS1307 RTC clock IC on board for datalogging. Version 2 has a header for a DS1307 RTC from Adafruit. Version 3 of the board is a minimalist version and does away with the FTDI connector but keeps the RTC header. All three versions of the board have an auto-switch power feature where the board is powered by USB if a FTDI breakout is plugged in but, auto-switches to external power when detected. I modified a power supply design I first saw in an issue of Servo Magazine.
I am working on a forth version that pares the design down further for cost. I'm waiting on those boards to come in.
The microcontroller of choice is a PIC16F877A or PIC16F887. Both chips are loaded with a bootloader so that I don't have to program the microcontrollers outside of the project housing.
Below are some pictures of the almost finished housing without the top on.
That's it for now. I'll explain some different control methods and software implementation later on.
Dang! it feels good to be back in business!
8 April 2011:
Pictures of the version 6.00 controller with the Adafruit DS1307 Real Time Clock attached.
I'm finishing the C# application that is stock full of features to control and graph the entire process. The application has real-time visualization as the reflow or bake process takes place. The reflow chart can be exported to an image and/or file for later viewing. In addition, the chart data can be exported to a CSV file so that it can be viewed in notepad or edited in excel. I've also somewhat integrated the bootloader application into the main application for controller firmware updates.
The application and controller is fully functional right now but, I'm exporting a lot of the functionality for control into class libraries to make them easier to update. This will also allow other interfaces to be developed using the libraries.
That's all for now, \o/
13 April 2011:
I'm pretty close to finishing the software application to accompany the reflow controller. Below is a simple demonstration video going through some of the menu options and functionality. I still need to actually demonstrate the controller operating with and without the software application. The firmware for the controller is done and has been tested but, as usual, documenting is the most tedious part. I'll post more videos tomorrow (time permitting).