Pages: [1]   Go Down
Author Topic: Serial to Mega2560  (Read 411 times)
0 Members and 1 Guest are viewing this topic.
Offline Offline
Jr. Member
**
Karma: 0
Posts: 55
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

I am trying to by pass the USB to serial converter chip on the 2560. I see lots of tutorials on how to do it with uno, but I am trying to do it with the 2560. I desoldered RN4 from the board (next to RX LED) and C7 (next to RESET-EN). HOwever, it does not seem to work. I rebuilt the MAX232 (and a I even tried a MAX202) several times. It is still a no go. Am I missing something? It just blinks like it is not even receiving a signal at all.
Logged

Seattle, WA USA
Online Online
Brattain Member
*****
Karma: 601
Posts: 48553
Seattle, WA USA
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

Quote
I am trying to by pass the USB to serial converter chip on the 2560.
Why? Only one of the 4 hardware serial ports (Serial) goes through the USB to serial converter. The other three (Serial1, Serial2, and Serial3) do not.

Logged

Offline Offline
Jr. Member
**
Karma: 0
Posts: 55
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

Well, I wanted to upload the programs via serial. I essentially just copied how it was done on Unos. I did not really think about the fact that the 2560 has 4 ports while the Uno has one, which is the reason why people bypassed that USB to serial chip on Unos to begin with. I really do not have to bypass the serial, I guess. Either way, I still cannot get it to upload the program with the arduino IDE....
Logged

Seattle, WA USA
Online Online
Brattain Member
*****
Karma: 601
Posts: 48553
Seattle, WA USA
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

Quote
Either way, I still cannot get it to upload the program with the arduino IDE....
Did you solder the resistor and capacitor back on?
Logged

Offline Offline
Jr. Member
**
Karma: 0
Posts: 55
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

Yes, but I still just trying to upload via the ports now....All I have to control is the reset and the 2 serial pins, right?
Logged

Seattle, WA USA
Online Online
Brattain Member
*****
Karma: 601
Posts: 48553
Seattle, WA USA
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

Quote
Yes, but I still just trying to upload via the ports now
Which port(s) The bootloader only listens to one of the serial ports (Serial/RX and TX).
Logged

Offline Offline
Jr. Member
**
Karma: 0
Posts: 55
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

I got it working....

turns out that the schematic in the datasheet (MAX 202) is not right for what I needed it for. The cap on pin 2 is shown with the neg side going to the supply. I brought it to ground instead and now it works. That was frustrating.

thanks!
Logged

Pages: [1]   Go Up
Jump to: