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Topic: arduino pro mini 3.3v cant upload (Read 3397 times) previous topic - next topic


Nov 23, 2011, 04:35 pm Last Edit: Nov 23, 2011, 07:06 pm by lyron Reason: 1

I just received my arduino pro mini 3.3v (http://www.sparkfun.com/products/9220) and i am trying to upload the "blink sketch" to it.

First i tried it with my usb ttl programmer hooked up like this:
ttl rx - arduino tx
ttl tx - arduino rx
ttl 3.3v - arduino vcc
ttl gnd - arduino gnd
ttl rst - arduino DTR

board selected: arduino pro or pro mini (3.3v, 8 Mhz) w/ atmega328.
but i keep getting the error
Code: [Select]

avrdude: stk500_getsync(): not in sync: resp=0x00
avrdude: stk500_disable(): protocol error, expect=0x14, resp=0x51

Then i tried hooking it up to a arduino without chip and reversing the rx and tx but nothing works...

any help?



I've tried reset a couple of hundred thousand times... :(


Gah! Not by hand... wire it up correctly and let the software do its job.


i did wire the reset on the arduino to the reset on my usb ttl


You need to wire the RESET coming from your USB thingy to the DTR pin on your pro mini. The reason is that a 100nF capacitor needs to be in there to create a reset pulse and not an 'ever-lasting' reset signal.

See the schematic.


i did hook up the rst on my usb ttl to the DTR from my arduino...


I'm having a similar problem my post is adjacent to yours.  Looks like maybe your TX/RX is backwards?  Should we use DTR or RST on my mini?  Reset on the Uno header is connected to RST on the chip?  So shouldn't it be connected to RST on mini?  Just looked, I don't see a RST pin on my DIP 328P.


Reset on a 328p dip package is pin 1.


Capacitor Expert By Day, Enginerd by night.  ||  Personal Blog: www.baldengineer.com  || Electronics Tutorials for Beginners:  www.addohms.com


The word 'BUT' should be forbidden in the troubleshooting forum.

I can't say how glad I am that airlines don't throw together various untested parts of unknown origin and hope the thing still flies.


I suggest that you stick to 'known good' parts. At least in the beginning. You will save yourself and us a lot of grief. Once you have a stock of working devices, you can buy others as well.


@madworm - To the DTR pin on mini? 

That's different from the RST pin.
Which one is correct?


It depends...

It is a known fact that the AVR chip must be reset with a short reset-pulse to make the bootloader kick in and get the upload timing right.

Depending on what kind of USB adapter you use (we don't know that of course), it may or may not create a pulse or just a static signal. You will have to look at the schematic of that contraption to find out. If it creates a reset-pulse, connect it directly to the RESET pin, if it creates a static signal, connect it to the DTR pin of the mini pro. Looking at the schematic of that piece of hardware will reveal that the DTR pin is followed by a 100nF capacitor that will create a reset-pulse, which then of course goes to the RESET pin of the mcu.

Is it just a feeling I have, or is the documentation of these products discussed here lacking a lot of essential content?


And if you can't get the friggin' bootloader to work, get yourselves a real programmer for <insert your favourite deity here> sake!

I predict that once you have one (and even if it just idly sits in its box somewhere), many problems will miraculously disappear. Just because.

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