Hi macpod. Just yesterday I order a Laserhark board to Barcelona (Spain). I hope to receive the order soon.
I have been reviewing the documentation regarding the LaserShark board, and I have some doubts. In the brief description you make of it, you say ...
"Lasershark v2.0 Specifications. ILDA-standard differential + /-10V 12-bit X and Y Adjustable output to get as close as possible to the spec."
and this picture say... (http://macpod.net/electronics/lasershark/images/lasershark_pinout_v2.jpg) descriptive that you contribute here. It appears that the voltage range is +5 / v-5v. Does that mean that the degrees of movement in the galvos are "limited" from suposed (-/+15V) to 1/3 of movement?
I hope recived my order soon.
Thank!
The LaserShark for the X and Y channel DO follow the ILDA spec. the output range IS NOT "limited".
The +5/-5v indications in the picture are the potential of that pin compared to
GND on the LaserShark board.
According to the ILDA spec, the X/Y signals are bipolar differential meaning you must compare the
+X pin with the
-X pin and the
+Y pin with the
-Y pin, not
GND.
As an example:
1. If the
-X pin is -5v and the
+X pin is 5v, this is a 10v differential.
2. If the
-X pin is 0V and the
+X pin is 0V, this is a 0V differential.
3. If the
-X pin is 5V and the
+X pin is -5v, this is a -10v differential.
Please see:
http://www.laserist.org/StandardsDocs/ISP05-finaldraft.pdfThe specification confuses many because the "Voltage range" column for the "X Axis (+)", "Y Axis (+)", "X Axis (-)", and "Y Axis (-)" states "+/-10V diff"
If you scroll down further in the specification you will see this is clarified with the following:
All signal receivers must have a true differential input stage! Unless otherwise indicated, the signal must always to be derived from the difference between the normal signal line and the corresponding inverted signal line. For example:
A differential voltage of +10V occurs if the normal signal line (+) has a voltage level of +10V with respect to the voltage level of the inverted signal line. (-)
