I am trying to connect an Arduino Nano to an Orion/Merlin head.
Because the connection is half-duplex I am connecting the Arduino TX/RX with 2x 220 ohm resistors to communicate, like this.
Arduino Port D0 tx <—> [220 ohm]
}<—> Orion/Merlin data port.
Arduino Port D1 rx <—> [220 ohm]
I always get an error when trying to upload a sketch to the Arduino Nano.
Binary sketch size: 4250 bytes (of a 14336 byte maximum) avrdude: stk500_getsync(): not in sync: resp=0x30 avrdude: stk500_disable(): protocol error, expect=0x14, resp=0x51
Now I just tried disconnecting everything except leaving the 2 Resistors in the D0 and D1 port with joint ends on the other side, there to say not connected to the Merlin at all. and I still get this error when trying to upload, disconnect the 2 resistors and everything is fine.
It does not what kind of Sketch I try to upload it tries and then brings this error up.
This guy was using one, I guess an older version of Arduino and it seemed to work for him.