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181  Using Arduino / General Electronics / My first PCB design with ATmega328P-PU, will this work? on: June 04, 2012, 11:51:53 am


This is my first PCB design based on the ATmega328P. All components are through the hole, took me some time to make the board without any vias. The board has an LM2576 3A 5V switching regulator. The L1 inductor is a lot bigger then the outline on the PCB that's why there is so much space around it. I'm new to Eagle so I haven't bothered making a symbol for it. I already have most parts including the LM2576 regulator and 3A 100µH inductor. I have one issue though, the regulators that I bought don't have the pins staggered, they are all 5 straight. When I put the regulator on the PCB in Eagle using a TO220-5 symbol with straight pins I couldn't get it to pass a DRC check. Even after changing the TO220-5 symbol to the smallest pads. It always complains that there is not enough space between the pads. So I just used the staggered symbol and I thought of just bending the pins on my regulators  smiley-red Does my design look ok? Or won't this work? I'm a bit worried about the regulator, that's why I've put so many caps on the board. I have a decent stock of caps so I might as well use them...
Datasheet of the regulator can be found here: http://www.datasheetcatalog.org/datasheet/nationalsemiconductor/DS011476.PDF

The board will be used for a couple of small robots using a bunch of small SG90 servos. With this design I can just connect the servos directly on the board. The regulator is powerful enough to power the servos. Power supply will come from a 2 cell Lipo battery.

I've attached the schematic smiley
182  Using Arduino / Microcontrollers / Re: Through the hole DIY Arduino: how to upload sketches? on: June 03, 2012, 03:56:23 am
Oh yes, TX/RX must be connected to RX/TX on the programmer. Thanks smiley
183  Using Arduino / Microcontrollers / Re: Through the hole DIY Arduino: how to upload sketches? on: June 02, 2012, 10:06:11 am
Ah, didn't know about ftdi cables  smiley-red
I've added a 6 pin ftdi header to my schematic. Connected GND/VCC, TX/RX to the corresponding pins on the ATmega and the DTR pin through a 100nF cap to the reset pin. I hope that will work if I buy a cable like this?
http://www.ebay.co.uk/itm/USB-TTL-5V-Serial-Cable-FTDI-FT232RL-Chipset-Arduino-UNO-mini-/270873825130?pt=US_Parallel_Serial_PS_2_Cables_Adapters&hash=item3f11568f6a

I've attached the updated schematic.
184  Using Arduino / Microcontrollers / Through the hole DIY Arduino: how to upload sketches? on: June 02, 2012, 07:18:05 am
Hi, I've been playing in Eagle 6.2 the last couple of days and made my own through the hole Arduino. I will use it to control a small robot, the board must power a couple of servos and sensors. I used a LM2576 5V 3A regulator that should be powerful enough. The schematic I have made is attached, can someone take a look at it and tell me if I didn't make any mistakes? In the schematic there is a small 100µH inductor (L2) connected between VCC and AVCC. I saw this in the schematic of the Arduino Severino, do I really need this?
The board only has an ICSP 6 pin connector, can I use this to upload sketches? What programmer would I need to do this? Or are there other ways to upload sketches without removing the microcontroller? Are there programmers that I could connect to my board which I could use for the serial monitor? Do I need another/different header for this? This would help a lot for debugging code. I already have a couple of ATmega328P-PU's that I have bootloaded myself on a breadboard with an Arduino Duemilanove.
185  Using Arduino / Microcontrollers / Re: Need a flight-proven µcontroller for cubesat mission on: May 28, 2012, 01:24:36 pm
Arduino in space -> http://arduino.cc/blog/2009/07/21/arduino-in-space/
186  International / Nederlands / Re: arduino nano V2.2 VS V3.0 on: May 26, 2012, 03:38:12 pm
Ik denk dat je die pagina nog eens goed moet lezen smiley I²C zit wel degelijk op de analoge pinnen 4 en 5 net zoals een Duemilanove/Uno.
187  Community / Website and Forum / Re: Login on the Danish Forum on: May 23, 2012, 01:52:26 pm
Uh, there is no Danish section. So I assume that the OP is asking about another website/forum? Or do you mean this part of the forum http://arduino.cc/forum/index.php/board,36.0.html ?

PaulS, Nederlands = Dutch, a language spoken in the Netherlands and the Flemish part of Belgium. I speak Dutch but I don't understand a word of Danish smiley
188  Using Arduino / Project Guidance / Re: Measurement in Cadsoft Eagle on: May 23, 2012, 01:07:32 pm
Try to find the dimension button  smiley-cool Near the bottom of the main toolbar on the left (well in my Eagle 6 setup).
189  Using Arduino / Motors, Mechanics, and Power / Re: WIll this Battery work with my 4 servos and my Arduino UNO board? on: May 15, 2012, 02:46:51 pm
You need a resistor between the base of the transistor and the Arduino. Also take a good look at the code you have posted, it won't do what you want it to do... The leds will never turn because you immediately turn them of.
190  Using Arduino / General Electronics / Re: 2n2222 from ebay? on: May 15, 2012, 10:39:24 am
I received my 50 transistors last Friday. I just checked 10 of them with my multimeter, they all have a HFE between 215 and 240. I think that's rather good smiley
191  Using Arduino / Project Guidance / Re: Determining heading for a robot based on the Arduino platform on: May 13, 2012, 03:58:10 pm
I suggest you do some reading on "tilt compensated compass". You'll will find a lot of information on these forums and other websites about digital compasses.
192  Using Arduino / Motors, Mechanics, and Power / Re: WIll this Battery work with my 4 servos and my Arduino UNO board? on: May 13, 2012, 05:09:34 am


Also, does anyone know the type of convertor this guy is using on the end of his battery? I think I will need something like this.



(this is the battery used in the above pic, but I thought it was kind of on the low side power wise, http://www.ebay.com/itm/battery-lipo-KingMax-500mAh-7-4v-25C-RC-mini-model-new-Free-Shipping-/230782766368?pt=Radio_Control_Parts_Accessories&hash=item35bbb98d20)

Thanks, Mike

Ha, that's my picture smiley I got the connector from Tayda electronics -> http://www.taydaelectronics.com/hardware/dc-power/dc-power-plug-2-1mm-x-5-5mm-x-9-5mm-right-angle.html I use the 500mAh battery to power my "Arduino remote control" -> http://www.bajdi.com/arduino-remote-control/remote-control/
193  Using Arduino / General Electronics / Re: cheepest place to buy blank 328 chips. on: May 06, 2012, 11:20:31 am
I looked on digikey and they can ship to Belgium
http://search.digikey.com/us/en/products/ATMEGA328-PU/ATMEGA328-PU-ND/2271026
Price Break   Unit Price   Extended Price
1           2.88000    2.88
25           1.80920    45.23
100           1.60800    160.80

prices are in USD




They have a Belgian website digikey.be but they only sell to registered companies. You need to provide a VAT number if you want to buy from them.
194  Using Arduino / General Electronics / Re: cheepest place to buy blank 328 chips. on: May 04, 2012, 11:00:38 am
Since I'm Belgian I can't buy from places like Mouser, Digikey or RS. I've ordered electronic parts from Tayda electronics in Thailand a couple of times. They sell the ATmega 328P-PU for 3,5$. That's cheap enough for me smiley
195  Using Arduino / General Electronics / Re: Pinout of 328 chip on: May 01, 2012, 03:33:20 pm
When I use a bare ATmega328 on a breadboard I use this drawing to see the pins:
http://www.hobbytronics.co.uk/arduino-atmega328-pinout
Very handy because it has the Atmel and Arduino pin numbers on it.
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