Watergius's Journal

The world as I see it

Category Archives: my final project

voltage changing using ADC in MSP430

This thing happened quite a long time a go, but I think I just want to write it anyway.


I was trying to use two ADC10 inputs in MSP430G2231 in order to produce a controllable PWM. This is the schematic for ADC inputs that I used (using simple voltage divider) :

ADC10 inputs

And it’s working. I mean, it can produced PWM. Then, I decided to check the voltage in ADC inputs. First, I check each voltage in voltage divider output (ADC1 and ADC2). After that, I connect the voltage divider to the ADC input port in MSP430G2231 (P1.0 and P1.1) and check the voltage back.


Here was the result that I got:

first measurement

Then, I tried to improvise by turn off the power source (both MSP and Voltage divider) for a short time and turn it on again, then measure it back. This was the result that I got:

second measurement

But, if I turn of the power source (both MSP and Voltage divider) for quite a long time and turn it on again , the result was like the first measurement (before I turn it off).

Okay, this was not what I expected… Still got no clue, I decided to ask about it in a forum. Luckily, I got a quick response and it turn out that the solution was really simple.

Here’s what he wrote:

Are the Rx, Tx, and LED0 jumpers in place? Remove them and test again.


Following his suggestion, now my problem has been solved. Looks like even the tiniest thing sometimes can cause big problem.. 🙂


another day in laboratory

finally I got my sense of engineering.. haha.. but that doesn’t mean that I spent almost 4 years in this institute without knowing it at all.. 🙂

assistant's room, fabio's laptop, and microcontroller -> PWM

had to move out from assistant's room and right now we're testing the MOSFET driver

conversion laboratory - left side point of view

conversion laboratory - right side point of view

final testing, the boost converter which turn out to be working fine (after some advise from Pak Nana)

inductor and LCR meter

Thursday, June 16


Yesterday we tested the MPPT under the bright sun. But, the result was not as we expected it should be. Something went wrong because we suddenly smell something burn from the inductor that we use for the boost converter. Looks like our inductor current rating is too small.

The output current from a solar panel is around 3 A. So, we need to use an inductor that would be able to sustain such current. But, since it is difficult to find one that is suitable, we decided to make one for our selves.

I always know that the basic principle for inductor are windings and core. For low frequency you use iron as its core, meanwhile for high frequency you use ferrit. Then, you should also decided how large (in Henry) the inductor that you want to build because it will determine how many windings that you want to make. And the tool that you would really need is LCR meter.

This is my first time saw this thing and also my first time made an inductor

LCR meter

our first inductor (sample)

It is called Subsystem

Last night, I was busy looking for a way creating something called “block” in Simulink Matlab. I thought it called block, but apparently I was wrong. That’s way when I search for it in the google with the keywords “making your own block in simulink matlab”, I got different solutions.

The basic idea of what that I want to do is making my “functional blocks” into one block so that I can use that one block for another functions.


my functional blocks

the one block that I want to make


After back to the basic which is reading the manual or documentation for Simulink Matlab from the beginning,  I finally got the answer to my problem. It is called subsystem or basically grouping your functional blocks into one  block.

How do you do it?

Select all the functional blocks (you can use ctrl + A). Then, right click and choose  “Create Subsystem”. And then, voila, you got what you wanted.