Hardware that works in a controlled lab and hardware that works in the field are two different things. After building embedded systems for deployment across Kenya and East Africa, we have learned — sometimes the hard way — that the design choices that matter most are the unglamorous ones.
Here are the five principles that guide every Savara Systems PCB.
1. Design for Voltage Variation, Not Nominal Voltage
Mains power in Kenya nominally runs at 240V. In practice, brownouts, surges, and unstable supply are facts of life, particularly outside Nairobi. Every power stage we design handles a wide input range and includes protection for over-voltage, reverse polarity, and ESD events.
We use wide-input DC-DC converters rather than linear regulators wherever thermal performance allows. A system that requires a stable 12V to function is not a reliable system.
2. Thermal Derating Is Not Optional
Kenya sits on the equator. Ambient temperatures in enclosed industrial enclosures — a control panel, a shipping container, a rooftop installation — can exceed 60°C. Every component we specify is derated to at least 80% of its rated maximum at the worst-case operating temperature.
This is basic engineering. But it is frequently ignored in designs adapted from temperate-climate references.
3. Connectors Are the First Point of Failure
In the field, connectors are handled by people who are not electronics engineers. They are connected and disconnected in the rain, in the dark, with dirty hands. We specify industrial-grade connectors with positive locking mechanisms, IP65 or better for any external-facing interface, and gold-plated contacts for anything in a high-humidity environment.
A beautiful PCB with a fragile JST connector on the power input is a liability.
4. Firmware Must Degrade Gracefully
A sensor failing should not crash the system. A communication timeout should not corrupt stored data. Every firmware we write includes explicit handling for hardware failures, watchdog timers for recovery from lockups, and non-volatile storage of critical state.
Embedded systems that work for years in the field are boring systems — they do exactly what they are told, even when the world around them is not cooperating.
5. Document Everything, Version Everything
Schematic revision B is not just revision B. It is the version with the corrected pull-up resistor on the I2C bus and the updated footprint for the new supplier’s voltage regulator. If that is not captured in the changelog, you will spend three hours in six months rediscovering it.
Every Savara Systems project ships with full schematic documentation, a BOM with approved alternatives, firmware source on GitHub with tagged releases, and a test procedure that can be run by a technician without an engineering degree.
The discipline of documentation is, in the end, an act of respect for future you — and for the client who depends on the system working long after the project is closed.