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Topic: First circuit ever (eagle schematic). Will it work (Read 782 times) previous topic - next topic

3d29

Hi guys,

This is my first project. I have been using arduino but now I want to build my own circuit. Please comment and/or help me out!

Will it work?

Thanks!

retrolefty

Not familiar with that specific processor chip, but there are a few obvious errors.

1. Both batteries are shown wired backwards.

2. The pin 1 reset should normally have a pull-up resistor to VCC.

3. Does this chip use it's internal oscillator? If not you need to add either a crystal/cap assembly or a 3 terminal resonator.

Lefty

Grumpy_Mike

#2
Sep 21, 2009, 02:26 pm Last Edit: Sep 21, 2009, 02:28 pm by Grumpy_Mike Reason: 1
Are you expecting to connect it to an R232 port on something? If so you will need a voltage converter like a MAX202 or similar.
I also assume that the processor has some software to drive I2C lines, it is shown connected to the SPI lines here, this is the same on some processors but not all. You also need pull up resistors on each I2C line, if Vcc is 5V then 4K7 will do.

How are you making the battery 5V?

I suspect that the crystal on U2 requires a capacitor to ground from each side.

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