Version 1.0 µSLC1 PCB Corrections
I must have been smoke'n sump'n when I did the layout for Version 1.0
as there are a couple of errors (can you believe it?!).
These only impact compatibility with the Spectra-Physics 117/A (and
functionally identical Melles Griot 05-STP-901) laser head and digital
purity. ;-) The following is only really relevant if you already have
a V1.0 PCB:
These changes are not required in most cases but are recommended for
compatibility with future releases. All of these can be done on the bottom
of the PCB.
- The wiring to the photodiodes is fine if you're building your own laser
head but is not compatible with the SP/MG laser head cable. For most people,
this is of no consequence.
- Cut the trace between J2-8 and J2-9 (Laser head DB9).
- Cut the trace between J2-8 and R13 (1K 1/4W).
- Cut the trace between J2-5 and R12 (1K trimpot).
- Add a jumper between J2-5 and J2-9.
- Add a jumper between J2-5 to R13.
- Add a jumper from J2-8 to R12.
- The order of the State LEDs is backwards. I know this will keep you
up at night. :) Swapping the State0LED and State2LED #define statements
in the firmware before compiling is the simplest solution but for the purist:
- Cut the trace bwteen U1-10 (Atmega) and R2.
- Cut the trace bwteen U1-12 and R4.
- Add a jumper between U1-10 and R4.
- Add a jumper between U1-12 and R2.
- The following is recommended to beef up the current capacity of the
- Add a jumper between J1-3 (Power connector) and J2-6.
- Add a jumper between J2-1 and Q1-C (center pin).