ColorHug+

[Valerio Messina]

hi,
Looking at the abandoned ColorHug+ schematics, it show as U6 a part
number "SPARK". Looking at the PCB I saw is has 14 SMT pins below the
package. With that information I cannot understand what is the device
brand and part number. It always come from AMS?

Also I cannot identify the user-replaceable:
"High CRI burnt-in tungsten illuminant"
and
"UV LED illuminant (for FWA measurements)"
part numbers, saw in the web page.
For confirmations, are LED2 and LED3 in the schematics, that are on the
sensor side of the PCB?

thank you,

--
Valerio

[Richard Hughes]

On Sun, 11 Nov 2018 at 10:56, Valerio Messina <efa...@gmail.com> wrote:
> Looking at the abandoned ColorHug+ schematics, it show as U6 a part
> number "SPARK". Looking at the PCB I saw is has 14 SMT pins below the
> package. With that information I cannot understand what is the device
> brand and part number. It always come from AMS?

Not AMS -- it's a now-discontinued part from OceanOptics:
https://oceanoptics.com/wp-content/uploads/SPARKManual.pdf

> Also I cannot identify the user-replaceable:
> "High CRI burnt-in tungsten illuminant"
> and
> "UV LED illuminant (for FWA measurements)"
> part numbers, saw in the web page.

The tungsten illuminant I was using for testing was sourced from eBay
(!) and was a 5V halogen 3mm bulb from what I remember. I never
decided on the UV source as a part number, one because the sensor
became unavailable and so research stopped, and two because when you
stick a UV source on a device there are additional "lockout"
considerations you need to factor in; you don't want the user to look
at the UV source even if they open the case...

> For confirmations, are LED2 and LED3 in the schematics, that are on the
> sensor side of the PCB?

Yup. There was a 3d printed light guide that directed the LED and
halogen bulb into the right "angle" to get reflected back from the
paper at 90 degrees.

Richard.