We would like to thank Hammond Manufacturing for providing us enclosures for our MPPT. Woo Hammond Rocks! Here is a link for their website below so you guys can check out what they have to offer.
Here is the picture of the enclosure we decided to use. It is the 1554 series.
Want your data on your phone? We have a Bluetooth App for that. The application was built with the help of the MIT App Inventor. The App Inventor uses a block-structured programming language and a blocks editor where you can assemble program blocks that specify how the components of the application should behave. The programs visual design and components are designed in the App Inventor visual design component which allows you to pick and place different things in the application such as buttons and labels. The best part is that it allows for Bluetooth Communication!
In the setup function, the line of code “Serial1.begin (9600);” activates the serial transmission on pins 18 (TX) and 19 (RX). The Arduino uses this serial port to transmit the panel voltage, panel current, battery voltage and battery current. Once the application has connected to the Bluetooth module; it gathers this data in a list (the equivalent of an array). This list is then searched for every item in the list and once a delimiter character such as X, Y, Z or D is found the next 4 items in the last are sorted into smaller lists and displayed next to their respective labels on the capstone App. The application is based purely on action programming; therefore an action must occur on the app for an execution of code. So when the get data button is pressed, the process described above occurs. Because of this sometimes there is an inconsistency with the results being displayed on the app and the LCD display. Shown Below are some screen shots of the application and the blocks used to program.
If you any questions feel free to ask us. We will have a download link to the app shortly! (Sometime close to the presentation date).
Our Buck-Boost PCB from OSH Park has arrived. This version uses more SMD components than the first version. This allowed us to reduce the area of the PCB by 35%. I immediately began applying flux and populating the board. Here are some images of the process:
The film on the gold plated pads is the flux. I positioned the first gate drive IC in this picture.
I then proceeded to solder all of the pins of the IC. This was done with a regular iron and flux. For surface mount work you don’t need an extremely fine iron. The surface tension of the solder causes it to have a tendency not to form solder bridged, when an appropriate amount of solder is used.
Chip capacitors were then soldered in place. We used many 1uF X7R ceramic capacitors because this was much more cost effective than using a single large capacitor. The capacitors must have a low ESR; electrolytic capacitors are out of the question.
The components for the snubber circuit were then populated. The snubber prevents destructively large voltage transients from developing when current through the inductor is interrupted.
Through hole components and the bottom side surface mount components were mounted. The populated board now resembles our original board.
– Soldered by Judson Tofflemire