The IoT under the Microscope.
Terror stalks the floor at MEA: Christmas is only a fortnight away and sales orders for our new CAT-M1 data loggers are raining down from above.
But production has jammed: SD memory cards are failing to pass production testing and the engineer who designed this part of the circuitry is incommunicado somewhere in Europe.
Our production engineer is going quietly mad with fear and frustration.
I need to step in.
It’s now 45 years since I graduated in electronic engineering from the South Australian Institute of Technology so these moments of terror are nothing new, though their impact never seems to diminish.
At these times I follow a standard routine to bring the young engineers through the crisis, while knowing full-well that I can no longer solve many of these problems myself. Designing IoT technology is a team effort. No single one of us on the product development team has all the skills to function alone.
So, I stay outwardly calm and clear some mental and physical space to sit down in a quiet place with our production engineer. I ask to be walked through the history of the problem. Then we take a look at all the circuit schematics and relevant data sheets.
It’s not that I am here to fix the problem myself, but merely to act as a mirror and a sounding board, asking penetrating questions if I find a weakness in the fabric of the case and quietly letting these talented youngsters solve the problem themselves.
The problem itself is simple enough. MicroSD memory cards that worked in previous batches and previous products don’t work in this new product though circuitry remains the same. Even part numbers remain unchanged. Worse, devices from the same manufacturer work from one source but not from another. We scour the computer stores around Adelaide, buying up small handfuls of different memory cards for testing, then ordering up many hundreds of the apparent successes from warehouses interstate. These then fail on arrival to work at all.
Nothing makes any sense.
Just for something to say, I ask to look at the schematic for the jellybean ESD protection part that protects the memory card from damage from static discharge during installation.
I’m no digital genius, but us old analog engineers recognise a low-pass filter when confronted by one; this thing is sitting on the memory card data bus, as it has done in previous products from this modem manufacturer, and has never before caused problems. I ask for it to be removed and tracks bridged over.
Suddenly, all the lights come on and even our worst-case memory cards start passing test.
Once again hardware re-work is needed. This is only possible thanks to a beautiful new microscope, beloved of all of us aging techos squinting at parts having twelve legs in the space of tiny resistors that have only two.
The production line grinds back into life and filling back-orders before Christmas is once again a possibility.
Off to the side, we rotate our techs through the microscope desk, laboriously upgrading valuable PCB assemblies with this new fix then feeding them into production.
Should I be feeling professionally remiss that this happened at all?
Nah! Software engineers roll out fixes seemingly forever. Scaling up production in the IoT will inevitably produce more of these moments of terror, allowing me to invoke yet one more old adage:
“When the going gets tough, the tough get going!”