A drip-irrigation controller spends its life next to a motor pump. The supply at that site is often the weak part of the system. Driptel, the GSM valve and pump controller Sai Agro Tel launched in 2013, was designed with that in mind.
What the controller has to survive
Driptel switches a motor pump and several valves, on a schedule, from a mobile application. The published hardware includes three protection circuits: phase-failure, voltage, and dry-run. Phase-failure and voltage protection are there for an unstable supply. Dry-run protection is there so the pump is not left running when water is not available.
Trip thresholds, the supply voltage and the pump rating depend on the pump and the supply at each site, so they are confirmed with the quotation rather than fixed in advance.
Why this belongs in the hardware, not only in the firmware
A schedule in firmware cannot see a missing phase or a dry well by itself. The board has to give the controller a safe way to detect those conditions and to disconnect the pump. On Driptel that detection is part of the hardware design, alongside the GSM radio, the keypad and display, and the valve and motor indicators shown on the front panel.
The same approach shows up in other work from the team. A six-layer weighing controller, described on the projects page, isolates its encoder interfaces and treats power, measurement and communication as separate problems on the board. Protection is a hardware decision, made before the enclosure is closed.
What to tell us if your board has the same problem
If a prototype runs on the bench and misbehaves once it is next to a motor, the useful first note is short. Say what the product switches, what the supply is like at the site, and which faults you have already seen. The hardware service starts from that: architecture, schematic, layout, and a bring-up that includes the protection behaviour.
Driptel is one product we sell. The same team designs controller boards for other equipment. The enquiry form asks for the requirement, the stage, and where the device will be used. Call +91 73500 20304 if you would rather talk it through.