I'm looking at some freeduino and arduino schematics for the serial port version and i see Capacitance marked C1, C2, etc... what are these and how do i arrive at a value?
I recently bought and built the Freeduino serial version 2 kit. The capacitors you mentioned are used by the MAX232 chip to generate the voltages needed to interface properly on the PC RS-232 end. The Aurduino board only has +5vdc power avalible, but RS-232 levels require a higher positive and also a equal high negitive voltage source. The caps are used by an internal DC/DC converter inside the MAX232 chip to generate those required voltages. There are of course other caps on the board and there purpose and value varies so you would have to be specific about which ones on which schematic.
Bye the way I found the board easy to construct in about 2 hours and worked right off the bat, however I have had lots of hardware experiance. At $17 + shipping it's one of the best deals going.
Lefty
You'll have to tell us which schematics you're actually looking at. EVERYONE calls their caps "C1, C2, etc..."
ok i figured it out and built it up Now the problem is with downloading programs.. i power up the board (freeduino) and then the led conencted to the pin 13 gives a very short blink and when i try to download there is no response from the led except for an occasional ununiform blink. I get the following error message
"avrdude: stk500_getsync(): not in sync: resp=0x00
avrdude: stk500_disable(): protocol error, expect=0x14, resp=0x51 "
any help is welcome....
OK, the normal hints... check your soldering and parts placement to assure the parts are connected the correct way. Check voltages, make sure you have the correct board selected and the correct com port. It would also help if you would tell us just which 'freeduino' you got and if you got a kit or bought the parts yourself and if you used any parts not called out bu the designer of the board.
Freeduino MaxSerial V1.2
Yes i've used the components specified, Bought them myself and the Atmega168 removed from my deumilanove.
Now i tried a serial communication test at the pins (digital 0 & 1) it doesnt work. So looks like problem somewhere around the max232. Will check this and keep updating this post. Also which one is better the Freeduino one I'm building or the Arduino Built by hand board. What is the difference? Would it be better i take the freeduino off and build the Arduino?
Freeduinos are based on the Arduino but each maker has a different idea of what is important. What is "best" is for you to decide since only you know what you want it to do and what features you need.