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Topic: standlone arduino  (Read 3648 times) previous topic - next topic

Paul__B

#15
Apr 11, 2015, 01:53 pm Last Edit: Apr 19, 2015, 10:16 am by Paul__B Reason: Image link corrected
so can you please give me a schematic that work good
"nerdegutta" just gave you the schematic in reply #4.  What more do you want?

Oh, all right then, here's the proper circuit, including the reset:

wizkhalifa

thanks you  very much sir

esdad697

Way to hard to build a circuit unless you want permanent connection. buy a cable from sparkfun  (or anywhere ) that has the converter built in and add a header to your board. This way you can use the converter with all your projects.

mrburnette

There is more to Arduino than the hardware.  There is the fuses, the bootloader, the interconnection to the PC, etc.

I know you have your circuit, but this link shows all the pieces.

wizkhalifa

hi my friends i have built the schematic of the max232  the first time i have tested it by attaching the rx and tx and open the serial monitor and sebd somthing and it work good but when it attached to my atmega328 and send the code i have the next message:



avrdude: stk500_getsync(): not in sync: resp=0x30

wizkhalifa

is that fromm the type of the board or somthing else

Paul__B

It could mean many things - it means that either the serial connections are not working, or more likely, the reset capacitor circuit is not correctly wired.

Make sure you have not committed the blunder of having a reset capacitor going to ground.

Budvar10

#22
Apr 14, 2015, 08:13 am Last Edit: Apr 14, 2015, 08:14 am by Budvar10
Try to check your circuit first as Paul__B mentioned. It is more often problem. You can test reset signal with DMM (should be visible change from Vcc to 0V and back) or with some LED with resistor in series. LEDs on Rx & Tx could be also helpful.
Another way is loopback test http://forum.arduino.cc/index.php?topic=73748.0 to make sure that the serial converter works correctly.
Last thing at now is to check the clock signal on ATmega's XTAL1 pin. Even though the new raw ATmega has set internal clock by default, the first try to program can change it to external so it is good to have a crystal or external clock signal connected. Simple test with DMM is to check DC voltage XTAL1-GND. It should be cca 2.5V since there should be high frequency 50% square signal.
Arduino clone with ATmega1284P   http://forum.arduino.cc/index.php?topic=277260.0

Grumpy_Mike

#23
Apr 14, 2015, 08:33 am Last Edit: Apr 14, 2015, 08:33 am by Grumpy_Mike
The fact that you got a number from the sync as opposed to zero or all ones suggests to me you have chosen the wrong bord in the IDE.

wizkhalifa

so in my case i have chip (atmega 328 so what is the board that i should choose it on the IDE

mart256

so in my case i have chip (atmega 328 so what is the board that i should choose it on the IDE
Depends on the bootloader you choose.
You can burn optiboot, then you have to select arduino uno as board.

CrossRoads

The circuit in Reply #15 is not the best:
Aref is connected to +5V - it should only have a 0.1uF cap to Gnd. See Fig 24-1 of the datasheet to see why.
There are no 0.1uF caps from VCC and AVCC to Gnd.
The RS232 chip does not show it's power and gnd pins, and is missing 0.1uF cap to ground for the power pin.
1K resistors on pins 2 & 3 are not needed.
Designing & building electrical circuits for over 25 years.  Screw Shield for Mega/Due/Uno,  Bobuino with ATMega1284P, & other '328P & '1284P creations & offerings at  my website.

Paul__B

The circuit in Reply #15 is not the best:
Meeeh, well, it was the best I could find in reasonable time. Good schematics are hard to find!

The RS232 chip does not show it's power and gnd pins, and is missing 0.1uF cap to ground for the power pin.  1K resistors on pins 2 & 3 are not needed.
Not strictly needed, true, but they are present on the UNO and Nano, in order to permit alternate functions for those pins, so they clearly do not hurt.

wizkhalifa

when i have buy my chip the bootloader was on it . should i burn the optiboot on it one more time .is that the cause

Budvar10

No, it is not necessary. It will be probably optiboot.
Arduino clone with ATmega1284P   http://forum.arduino.cc/index.php?topic=277260.0

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