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Topic: ZIFduino (Read 5 times) previous topic - next topic

eustace

Is that preview version for use with the FTDI cable?  Getting rid of the chip makes the board easier to build, but it would also eliminate the point of the Zifduino, at least for me.  Using that cable, I could program my Boarduino's directly.

aballen

I like the idea of using the ftdi cable, it knocks a few bucks off the price, and removes the most difficult part from the board.

which reminds me, bitty I got the rest of my parts, it diddnt work for me, the tx light blinks 3 times when I power it up.. thats all...

I tried to clean up the soldering on my usb chip... and I burnt the traces in the process :(

I would be happy to try again if you have a new design, I've got lots of spare parts now.


aballen

hey bitty, just got that extra board you sent me

Thank you.

I put it together, flashed it and have my simple blinky running(led on pin13).  For some reason the red leds don't light up, power and rx.  I'm not sure but perhaps the 220ohm in place of the 330 was just too low, and they popped... I'll have to read the specs on the red ones.. I hope I have a few left.

I'll test the rest of the pins for digital and pwm this weekend if I have a chance.

so far I say gratz, it appears to work, perhaps you will refine it... but it is definatley working!

More feedback to come.

Bitty

;)

Glad to hear it's working for you.  I'd recommend replacing those LEDs and going with a higher value resistor.

The boards are being sent in for manufacturing on Monday.  I'll post a link when kits are ready for shipping.

aballen

yep, either the red leds were put in backwards or the long lead was the cathode... I flipped them around, and the red power led induced temporary blindness ;)  when I was able to see again I switched it with a 1kohm resistor, and the light is more consistent with the other leds.

ok, digital out tested on all pins, PWM out tested on 3, 5, 6, 9, 10 and 11.

I'll test some analog in tonight.


aballen

well got it done after breakfast.

all analog in work es expected, icsp header works great, reset button works too.

I think thats everything, but a pic of the working one.



silly question.  can you reduce the number of caps?  I know the arduino decimilia has a similar number of parts, but if you look at something like the boardunio, much fewer parts.  Just a thought.

Let me know if you want me to test your other variants.. I have an ftdi cable.

kg4wsv

Quote
can you reduce the number of caps?

IIRC, ZIFduino (and the Decimilla) contain the minimum number of caps recommended by the data sheets of the components.  The only "extra" on there is the coupling cap for the auto-reset functionality.

-j


aballen

well there you have it.

how to boards like the rbbb, or the boarduino get away without all the caps?

kg4wsv

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how to boards like the rbbb, or the boarduino get away without all the caps?

Reduced functionality.

The 7805 regulator requires 2 caps minimum.  Leave off the 7805 and say goodbye to 2.

The FT232RL (USB chip) recommends 4 caps in their reference design - leave off USB support, and there go 4 more.

A typical crystal needs 2 caps - use a resonator with built-in caps, and lose a couple more.

The ATmega recommends an analog filter cap between AVcc and GND - don't do any analog input, and you can probably get away with leaving that one off.  In addition, pretty much every digital IC should have a .1uF between Vcc and GND.  If you feel like troubleshooting bizarre random problems, leave that one off. |:

The RBBB has 4 caps, the 2 for the ATmega and 2 for the 78L05.  It uses a resonator to avoid the XTAL caps.

The boarduino has 6 caps.  Just guessing here, but I think 2 are for the 7805, two for the ATmega, I think the fifth is for auto-reset, and I'm guessing the 6th is an extra power supply filter.

-j


spiffed

Quote
The 7805 regulator requires 2 caps minimum.  Leave off the 7805 and say goodbye to 2.

Technically, the 7805 requires no caps for operation, only for increased transient response or (very) noisy supply lines. Arguably removing the 7805 necessitates the use of a capacitor or two because you're moving the power supply away from the system and all transients must be handled by capacitance.

Reading from the datasheet
Quote
Cin is required if regulator is located an appreciable distance from power supply filter.
CO is not needed for stability; however, it does improve transient response. Values of less than 0.1 uF could cause instability.


In practise, the price of two caps is less than the worry of ignoring the gotchas.
iDuino - MaxSerial - [url=http://spi

gradbert

Quote
It's set up so you can use either a crystal or an oscillator.  A lot of people don't care either way, but a lot of people do.  I figure it's better to give the option.


Good idea, the resonators are typically +- 5% of the desired frequency.  If you are doing something like building a clock a 5%  error would mean your clock would gain or lose over an hour a day.  Or if you are generating a tone, it could be off by almost  a 1/2 step.



Bitty

http://bittyware.com

:D :D :D

mellis

Congratulations!  Those ZIF sockets are expensive, huh?  

I like the way you created a separate item for the FT232RL solder option.  Makes it easy for people to pay for it or not as they want.

Bitty

Yeah, and the big fat board isn't exactly cheap to have manufactured in small quantities. ::)

The_Bongmaster

YaY :D nice work :3
B-dui in creation.

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