Integrating

Every problem in this section is invisible on a bench, which is why a module that images beautifully in an evaluation kit can still fail as a product.

For the team-process side of engineering work, handling multiple clients efficiently is a separate reference on organizing and reviewing work.

Mounting and tolerance — one degree of tilt displaces the view by roughly 17 mm per metre, which makes mechanical tolerance an imaging specification.

Flex cables and connectors — the part most likely to fail mechanically, where a sharp assembly fold passes every test and fails in service.

Signal integrity on the interface — why a link works at one cable length and not another, and why the failures look like a broken module.

Further background is available from scikit-image.

Power and noise — an analogue sensor on a digital board, where the illuminator sharing a rail makes the image worse with the light on.

EMC and the camera as an antenna — emissions decide whether the product can be sold and immunity decides whether the image survives the machine.

Thermal: the sensor gets hot — dark current roughly doubles every several degrees, and an open bench hides all of it.

Dust, water and condensation — condensation defeats a perfect seal, because the water was sealed in with the air.

Vibration and shock — continuous and small against occasional and large, with different remedies and a resonance that appears at one machine speed.

The window in front of the lens — an optical component, and tilting it a few degrees removes the ghost for the price of a drawing change.

Illumination as part of the design — five geometries, each making something visible and something invisible.

Firmware, drivers and the bring-up — rails, register read, test pattern, real image, in that order.

What changes at volume — a prototype is one sample of everything and production is a distribution of each.

• EMC and the Camera as an Antenna

  High-speed signals on a cable radiate and receive. What that does to compliance and to the image, and what fixes each.

• Flex Cables and Connectors

  The part that fails mechanically while the electronics are fine. Bend radius, connector cycles, and why length is an ordering decision.

• What Changes When You Go to Volume

  A design that works on ten units and fails on a thousand. Six things that appear at production and how to find them early.

• Illumination as Part of the Design

  The half of the system designed last and solving most of the problems. Five geometries and what each makes visible.

• Dust, Water and Condensation

  Sealing an enclosure that has a window in it, and why condensation defeats a seal that stopped everything else.

• Mounting and Tolerance

  A module aimed by its mounting, where a fraction of a degree moves the field of view. What to control and what to allow for.

• Power and Noise

  A sensor is an analogue device on a digital board. Where supply noise enters the image, and what separates the rails that matter.

• Signal Integrity on the Interface

  Why a link works at one cable length and not another, what the failures look like, and the rules that avoid them.

• Firmware, Drivers and the Bring-Up

  The item most often underestimated in a module decision. What has to exist, what to ask for, and the order that finds faults fastest.

• The Window in Front of the Lens

  A flat plate in the optical path is an optical component. Reflections, ghosting, and the angle that removes both.

• Thermal: The Sensor Gets Hot

  Noise rises with temperature, and an enclosure changes everything a bench test showed. Where the heat comes from and what removes it.

• Vibration and Shock

  Two different loads with different remedies. What vibration does to an image, and what shock does to an alignment.