how about including the m122 output?
Your using aux-2, but sadly image is not clear enough to see what pins are going where
Not all pins on the Mega and Mega 2560 support change interrupts, so only the following can be used for RX: 10, 11, 12, 13, 14, 15, 50, 51, 52, 53, A8 (62), A9 (63), A10 (64), A11 (65), A12 (66), A13 (67), A14 (68), A15 (69).
So you have to ensure that your using 63, 64, 65, 66 as RX pins.
Should be wired as
Your using aux-2, but sadly image is not clear enough to see what pins are going where
Not all pins on the Mega and Mega 2560 support change interrupts, so only the following can be used for RX: 10, 11, 12, 13, 14, 15, 50, 51, 52, 53, A8 (62), A9 (63), A10 (64), A11 (65), A12 (66), A13 (67), A14 (68), A15 (69).
So you have to ensure that your using 63, 64, 65, 66 as RX pins.
Should be wired as
GND|D63 |D40 |D42 |D65 5V |D59 |D64 |D44 |D66 GND|X_RX|X_TX|Z_TX|Z_RX 5V |Y_TX|Y_RX|E_TX|E_RX