Project.
Greenhouse Environment Monitor/Control Project.
Today I am doing the SCM of the LCD Display Shield V2. This is done by using the Arduino Shield Rev3 which is composed of 4 components.
The software seem to be causing some problems and therefore causing a delay in order to finish the schematic itself.
To make this schematic I need to pay much attention to the smallest details in order not to miss anything out. e.g. the inputs and the outputs which are very necessary when the finished piece is being put into action.
The problem with the software cost us a lot of time as it made us wait for a very long time.
This waste of time is not good in my opinion because it start showing a bad sign in the very beginning while I want to get stuck directly into the second schematic.
Getting the part names of the components seem like a challenge in the beginning because they are so many of them and each one has to go in the correct order; to avoid mistake of the PCB and the Artwork.
To conclude, it was worth it to come to the lab early and get all the instructions about how to start the project itself. I also gain more knowledge on what the project is all about. i.e. Green House.
The Fan Control section of the board we had to work out the value of R1. The resistor was connected to one of the ports on the 15 pin connection and then through a transistor (BC337).
First step was to find the current of the fan using the formula I=P/V ( Current= Power/Voltage )
P=1.23W
- V=5V
- I=246mA
The data sheet of the BC337; I was able to found out the beta value, which was 400. With this at hand I worked out the base current. IB=IC/Beta
- IC=246mA (from above equation)
- Beta=400 (from data sheet)
- IB=615 microA
The final voltage is 4.3, because of the 0.707V voltage drop from the BC337 ( The NPN transistor ).
The value of R can easily be find by using the following formula: R=V/I (Resistance= voltage/current ).
- V=4.3 ( 5V - 0.707V )
- I=615 microA
- R=4.3V/615x10-6A
- R=6.99 kOhms
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