Nexus robot - Can't upload to arduino unless unplug io bad

Help & Support Robots & Kits
1

I have a Nexus Mecanum 10021 robot kit. I can’t upload a new program to the arudino 328 mega unless I remove the IO board.

I have gotten the same errors on both Mac and Windows install of at the ardruino IDE.

Any ideas?

2

Hi,

This is normal with the Nexus boards, the RS-485 chip is connected to the serial bus and only one serial is available on those micro controllers.
It’s not software but hardware related.

If you do not use the RS-485, you could disconnect or cut the pins between the Arduino and the shield.

:slight_smile:

3

Is this only a USB progtamming issue?

Can serial and rs485 both be connected to different devices and working?

Can USB and rs485 both be connected to different devices and working.

4

The expansion board have the pins connected directly to the main controller.
You can have a look at he schematic HERE.

The main board (microcontroller) share a similar configuration with Duemilanove HERE.
Only one “serial” port is available on D0/D1 which is aslo used for USB.