Forum >IO Expansion Shield (V5) error with RS485
IO Expansion Shield (V5) error with RS485
stancrm 2012-08-01 02:28:54 4038 Views3 Replies Hello. I'm using Arduino Uno with IO Expansion Shield V5. I want to communicate with PC using RS485. If I set all 3 jumpers to RS485, I cannot upload the codes to arduino. It says :
avrdude: stk500_getsync(): not in sync: resp=0x00
I set all 3 jumpers to 485 and connect A and B to my RS485 in PC.
Thanks.
avrdude: stk500_getsync(): not in sync: resp=0x00
I set all 3 jumpers to 485 and connect A and B to my RS485 in PC.
Thanks.
2012-08-01 18:17:50 If I send something to Arduino Uno with RS485 (using IO Expansion Board), should I see "Blink" in TX & RX ? stancrm
stancrm 2012-08-01 17:25:33 To add a bit more info:
The Arduino only has 1 physical serial port which is used by the USB cable to upload your sketches. The IO Expansion shield also makes use of this port for RS-485 OR Xbee communications. IF you connect something to these ports then you do not allow the USB access to the Arduino's serial port and that is why you get the error message.
There is 2 solutions to this problem:
1. Disconnect anything from RS-485/Xbee
2. Remove the jumpers
The replace after you have finished uploading your new sketch.
Hector
The Arduino only has 1 physical serial port which is used by the USB cable to upload your sketches. The IO Expansion shield also makes use of this port for RS-485 OR Xbee communications. IF you connect something to these ports then you do not allow the USB access to the Arduino's serial port and that is why you get the error message.
There is 2 solutions to this problem:
1. Disconnect anything from RS-485/Xbee
2. Remove the jumpers
The replace after you have finished uploading your new sketch.
Hector 2012-08-01 06:05:44 You must remove the jumpers in order to upload sketches. As long as you finished the uploading, apply jumpers to let your pc communicate with arduino via rs485. 
R2D2C3PO
R2D2C3PO 