Author Topic: my 1st board design, does it have problems?  (Read 1173 times)

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Offline 123laurensTopic starter

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my 1st board design, does it have problems?
« on: September 07, 2011, 04:45:47 AM »
you dont know how long it took me to find out how eagle, and eagle3D works. well, eagle is giving me all these warnings, warning me that power pins on the IC are connected to wires(they are meant to, right?), along with saying that pin headers dont have values(what values?) along with my noobish electronic skills.
NOTE: I am NOT planning to make this into a PCB, this is my 1st design, and i just want to know weather it whud have worked if i did want one.

features/explenation: it has 2 switches. 1 is for power to the board, and another is a programming mode switch. in my robot, PRObot V1.1 i had simalar, but seperate from the board. i design my code to not drive the motors when this switch is on, and will later enter a serial debug mode(requests witch sensor you want to display data of, and set servos). this is EXTREMELY usefull for me, buecause this means i can program my robot without it trying to escape my desk.

and yes, i know, it does not have an ISP header thing. but my ardurino does, and I am planning to program it on there, then put the chip in there.
and yes, I know, that removes the point of the switch. but still, this is a proof-of-concept.

EDIT: also, it has no power regulator. just noticed that now. pretend im using a stable 5V power.

3D version:(just cuz it looks cool)



a link to the video of my PRObot, to showing the usefullness of the switch/ my experience: http://www.societyofrobots.com/robotforum/index.php?topic=14416.0

I do hope this thing works. but there are probably 20 or so problems with this.
« Last Edit: September 07, 2011, 08:14:10 AM by 123laurens »

Offline 123laurensTopic starter

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Re: my 1st board design, does it have problems?
« Reply #1 on: September 09, 2011, 03:12:51 AM »
newer version of the board:
now with power regulator!
its more compact!(and looks way cooler)
those red boxes are 20uf ceramic capacitors




the new wiring:

full sized image, for if it is to small: http://i.imgur.com/pbzQW.png
whud this work? if i were to get it made?
i'm not, of course, just want to know if im not missing anything necessary, BESIDES the ISP header witch i left out on purpose.
« Last Edit: September 09, 2011, 03:14:08 AM by 123laurens »

Offline Ro-Bot-X

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Re: my 1st board design, does it have problems?
« Reply #2 on: September 09, 2011, 05:34:54 AM »
You're missing the 10k pull up resistor on the Reset pin. Never let it floating or you'll have unreliable results. Also, the crystal capacitors are 22pF not 22uF. Make the trace thicker for ground and servo power. Don't forget, you will also want to attach sensors to this board, have them connected to 5v regulated, not servo power.

To fab the board, try out Sparkfun's Batch PCB service.
Check out the uBotino robot controller!

Offline 123laurensTopic starter

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Re: my 1st board design, does it have problems?
« Reply #3 on: September 09, 2011, 07:40:54 AM »
You're missing the 10k pull up resistor on the Reset pin. Never let it floating or you'll have unreliable results. Also, the crystal capacitors are 22pF not 22uF. Make the trace thicker for ground and servo power. Don't forget, you will also want to attach sensors to this board, have them connected to 5v regulated, not servo power.

To fab the board, try out Sparkfun's Batch PCB service.

10K resistor, does it just go from power to reset?
thanks for pointing out the capasitors. i probably read something wrong.
ill se if i can foind out how to make it thiker.
ok, 50% for servos and the rest for sensors.

batchPCB: i think it only works in USA?
also, i found anotheer cheap service: http://www.dorkbotpdx.org/wiki/pcb_order
Quote
It's $5 per square inch for three copies of your two layer design. So, a 2 square inch design would cost $10, and you'll get three copies of your board. Shipping within the US is included, and there are no setup fees.

elsewere it seas that international orders cost an extra 5$. this is by far the cheapest service ive seen. the second cheapest service, http://www.jackaltac.com/ seems far off this price.
how cheap is batchPCB?

Offline 123laurensTopic starter

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Re: my 1st board design, does it have problems?
« Reply #4 on: September 09, 2011, 10:22:13 AM »
new scenamic:

not mutch changed, i still have to seperate the servo-sensor ports. i forgot to upload the file, i was done a while ago...

Offline 123laurensTopic starter

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Re: my 1st board design, does it have problems?
« Reply #5 on: September 12, 2011, 04:15:06 AM »
ok, so i think im getting used to eagle, and i now have a design that i might get made some day:

basicaly, its a watch like computer thing/scedule, still loads of work to be done, but yea.
LCD wiring is based off this thing:
http://arduino.cc/en/uploads/Tutorial/LCD_bb.png
since i am using an uno to program the chip, i did it pin by pin. my worry is, it seems to be using the pins you whud use for an ISP header. that is the main question. it will also have an Xbee or something similar for remote control, or with a real time clock module.

P.S. how do you make measurement in the PCB layout thing? i need to see if the LCD whud cover the buttons.

Offline Ro-Bot-X

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Re: my 1st board design, does it have problems?
« Reply #6 on: September 12, 2011, 06:02:25 AM »
The xBee uses only the Tx and Rx pins to communicate with the microcontroller. Same thing with a Bluetooth module. I don't know about the real time clock (RTC) module.

The only modification I would suggest is to move the connection for the LCD E (enable) line to pin 6 and the RS line to pin 7. This way you will have Timer2 available for the Tone library, in case you want your robot to play Beeps or simple songs for entertainment. Just make sure you mod the code for the LCD accordingly.
Check out the uBotino robot controller!

Offline 123laurensTopic starter

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Re: my 1st board design, does it have problems?
« Reply #7 on: September 12, 2011, 06:47:44 AM »
The xBee uses only the Tx and Rx pins to communicate with the microcontroller. Same thing with a Bluetooth module. I don't know about the real time clock (RTC) module.

The only modification I would suggest is to move the connection for the LCD E (enable) line to pin 6 and the RS line to pin 7. This way you will have Timer2 available for the Tone library, in case you want your robot to play Beeps or simple songs for entertainment. Just make sure you mod the code for the LCD accordingly.
im planning to use the tx and rx pins, witch is why I left those free.

and i dont know about the LCD thing... its a default libary, and it looks pretty complex.
i gess i can use a speaker, but know that i'm planning to wear this on my wrist of put in my pocket as the ultimate nerd watch. just got another idea: TV remote!
so, it whud need to be a speaker that can fit on the PCB. and I probably wont use it.

Offline totalis

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Re: my 1st board design, does it have problems?
« Reply #8 on: September 12, 2011, 08:41:03 AM »
I am aware that this may defeat the point of the exercise but i have recently made a MCU based upon the atmega328P I had a batch of PCB's made and i have built and tested them, they are quite compact at 5cm x 5cm and have a programming header.  I have about 7 left to sell at ú10 each + P&P

There are pictures on this thread:

http://www.societyofrobots.com/robotforum/index.php?topic=13918.msg104199#msg104199

sorry for the shameless plug but if it saves several hours and unnecessary headaches then all is well

T

Offline Ro-Bot-X

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Re: my 1st board design, does it have problems?
« Reply #9 on: September 13, 2011, 05:41:17 AM »
Nice Totalis! I see you went for the SMD version of the micro, that makes the board look less crowded. I've made a few boards myself, but I used the TH version, because I sell them as kits. My most successful board is the ÁBotino (see the link in my signature), but similar with yours is the ÁServotino. I had a manufacture defect on the first batch that prevented the auto-reset function and I also wanted to include a way for the servos to be powered after they get the signal from the microcontroller, so they don't make that jerky move at power up.
Check out the uBotino robot controller!

Offline Soeren

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Re: my 1st board design, does it have problems?
« Reply #10 on: September 15, 2011, 07:14:43 PM »
ok, so i think im getting used to eagle, []...

P.S. how do you make measurement in the PCB layout thing? i need to see if the LCD whud cover the buttons.

There's a couple of ways...
Use the info button and click on a wire/line and you get the length (among other parameters of the wire/line.
Draw a line and the measure is dynamically shown above the upper left corner of the drawing area.

Set up the grid (View -> Grid) to show the units you like. If you prefer metric measures, you can set it like this:


This way you'll get a grid line each 1cm and the resolution will be 0.1mm (good enough for most work). This works for both of the methods described above as well.

Remember to reset the grid to what you prefer when drawing, or you'll find it impossible to align components to 1/20" or whatever you use (the button "Last" will do that quickly (if you didn't set it to metric measures in more than one go) and the button "Default" will set it to... Surprise... The default value (which happens to be 1/20").

This may look slightly different in newer editions of Eagle, as I stick to version 4.16 - the 5.xx versions are too low contrast for my liking.
Regards,
S°ren

A rather fast and fairly heavy robot with quite large wheels needs what? A lot of power?
Please remember...
Engineering is based on numbers - not adjectives

 


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