úterý 21. srpna 2012

New project

The summer is almost gone and I'm moving onto another project.
Idea is: Arduino based control panel for my analogue transistor based power supply with current limiter.

What I want: Graphic LCD, rotary encoder, 16bit ADC converters reading voltages & current, digital Potentiometers setting voltage & current. Few buttons, few LEDs.

Why I want it? 
I built a power supply 0-30V 0-3A that serves me well for around a year, but would like to give it more of a digital touch. And its a little bit challenging. (Third project with MCU).
Hopefully I'll manage to take the best from digital & analog world :)

Wish me luck.

BLuetooth L6 breakout board

I've added a small board for Bluetooth L6 module with 3.3V to 5V TTL converter and LEDs for status & pairing info.

pátek 3. srpna 2012

DIY Arduino 180 RGB LED Wall clock

I've added all files for the Arduino clock
Everything is running fine, but the animations are still not done. Maybe in the future.
So what can it do?
Show time, date, temperature, humidity and self adjust brightness.
It's changing colours and ways it is showing time.
+ I think my program is easy enough to modify for everyone (my programming skills are low and everything is written that way)

Feel free to change, modify, upgrade ...

sobota 26. května 2012

pátek 25. května 2012

The ambilight is up and running. I'll post all the schematics, source code, and video tomorrow

pondělí 21. května 2012

At this stage and after testing, I can say, the ambilight board is working perfect with the boblight so I'm going to post the eagle files soon. The only thing I'm a bit concerned about is the current draw. I'll see if the 0.3mm traces for the power will be enough. I placed a capacitor close to the Atmega so hopefully it won't brown out at peaks. I have to go back to work now, but  in the evening I'll start working on the RGB strips.

neděle 20. května 2012

One thing with the Arduino nano design ... It's not working ! When I connected the board to the PC I got error message: USB device not recognized. After few hours of desoldering, soldering, ,checking, measuring continuity I got desperate, opened the FT232RL datasheet and found that TEST pin has to be connected to ground, which is not in the arduino nano schematics.

Fortunately there is pin beside what is GDN, so just a bit of solder to shorten these pins and voila, drivers installed. Burned bootloader using second arduino board as ISP and now I'm running succesfully "Hello world" sketch on my new board :)

Next step: check the communication with TLC5940 and write the code for recieving from serial port and writing data to SPI. This time the chip doesn't have to do much :)

Have I mentioned, that there is also photoresistor? Have to figure out how, but I'd like it to adjust the ambilight to the actual ambient light (If enabled)

Oh yes, and BTW ... I have already done board design for the LED strips. In local shop they want 15€ for 0.5m strip with 6 LEDs on it! What a ripoff. My ones will be 30cm with 6 RGB leds on it.
I'm making 10 of them (3 top, 3 bottom, 2 each side of telly). I still have around 70 LEDs left over from the clock project, they'll come in handy
Arduino Ambilight

On wednesday I've decided to build an ambilight for my flatscreen TV. After a bit of googleing I found the Amblone, but it has only four channels. Then I found BobLight. It is great idea, simple and you can have as many channels as you like. Downloaded the software, installed virtual COM port and watched the data being transmitted. Simple enough. Now the hardware.

At first, this was perfect to try my new LED exposure unit. Google again and looked for schematics. There is a good few of them around, so I took idea here and there and started to design my own.

Schematics were based on the Arduino Nano, The FT232RL gives USB connectivity, Atmega 328P-AU is great foe what I need, as PWM drivers I'm using TLC5940. There is a great library written for the TLC5940 and I have previous experience with that chip. To get enough of current I found logic PNP transistor what can handle up to 500mA of current and has pull-up resistors and base resistor (less parts needed).

Parts came on friday (under €30 for the whole lot + some I needed to restock, like LEDs, resistors)

When I was making the board (first time using photoresist and UV light) I run into a problem. I couldn't get an even coat of the photoresist. Cleaned, degreased, I tried solvent, acetone, acid, nothing. I was a bit desperate, so forums (thank god for them) and found the answer after couple minutes. You have to be in absolute dark when spraying. So half can of photoresist later I got a perfect coating. Exposing itself was easy, etching is a daily bread.

sobota 12. května 2012

LED Clock

That one isn't finished yet. But the preview is up
I've just added first post with DIY exposure unit.

1st post

My Electronic Projects

Welcome to my new blog. 

I'm just a guy what is interested in electronics. I'm not Pro, it isn't my job, I just like it. I've decided to post some of my projects here on this blog in a hope it might be useful to someone.
Hope you'll like it :)