Programming Arduino via RS232 TTL MAX233

I’ve been fussing with this issue fro a while now, and i am at a loss. i recently purchased a pro mini (the one with off-board USB) and am trying to program it. now, i do not have the FTDI breakout board or cable, as i thought i could use my setup.

I was intending on programming my pro mini via rs232. from what i’ve read, you cant just take rs232 level signals into the pro mini, they must be TTL. so i dug up one of my rs232 to TTL chips, Its a MAX233. i hooked it up, and after countless combinations of wire switching, i still cant get the arduino software to upload my sketch. i am using my laptop’s built in serial port. not one of those cheap usb to rs232 adapters.

Heres the configuration i thought was the most likely to work, but didnt.

With the MAX233 chip in my serial port, i provided the chip’s Vcc with +5 and ground. the TXd of the CHIP i put on the pro mini’s RX1, and the RXd of the MAX233 chip to the pro mini’s TX0.

now i know the MAX233 does not bring out the DTR for the automatic reset, so i brought that right off the serial port to the reset line.

When i hit upload, it compiles, thenit tries to upload to the I/O board. the board resets (i see the LED blink) but then it just times out. ive tried manual reset, ive tried close to everything!

Is this not possible? MUST i purchase a FTDI board or cable? from what i can tell, the FTDI also uses TTL. i dont understand why my configuration is failing.

Any help is greatly appriciated! thanks!

i am glad to report that i have some how resolved the issue. i just wanted to let YOU know that it IS possible to program via RS232 and a MAX232 RS232 to TTL converter. i believe my issue was a combination of several things. first, my wiring was not shielded and was kinda messy. in addition, i think the first MAX232 chip i used, had some issues. I had a second MAX 232 chip, i hooked it up with an old USB cable i scrapped (i used the cable for the shielding, high quality coppers, etc…) and it uploaded great! Also, i powered the MAX232 chip off the USB bus on my computer. So bottom line, it works great, if anyone else has a similar issue, hopefully i have help a bit!

IT IS POSSIBLE TO PROGRAM AN ARDUINO VIA RS232 VIA A MAX232 RS232 TO TTL CONVERTER