try-fix: tbeam router goes sporadically into DS

[mverch67]

It has been observed that a node which is configured with device.role ROUTER is sometimes dead after a while.

It is suspected that the dead node is in deep sleep which normally happens only when the battery percentage falls below 10%. However it may happen also in case the battery readings deliver a wrong too low (or zero) value. For NRF52 the code requires ten subsequent measurements below the 10% threshold. For ESP32 only one(!) measurement below the threshold causes immediately a transition into deep sleep:

Power.cpp
// If we have a battery at all and it is less than 10% full, force deep sleep if we have more than 3 low readings in a row
// Supect fluctuating voltage on the RAK4631 to force it to deep sleep even if battery is at 85% after only a few days
#ifdef ARCH_NRF52
        if (powerStatus2.getHasBattery() && !powerStatus2.getHasUSB()) {
            if (batteryLevel->getBattVoltage() < MIN_BAT_MILLIVOLTS) {
                low_voltage_counter++;
                LOG_DEBUG("Warning RAK4631 Low voltage counter: %d/10\n", low_voltage_counter);
                if (low_voltage_counter > 10) {
                    // We can't trigger deep sleep on NRF52, it's freezing the board
                    // powerFSM.trigger(EVENT_LOW_BATTERY);
                    LOG_DEBUG("Low voltage detected, but not triggering deep sleep\n");
                }
            } else {
                low_voltage_counter = 0;
            }
        }
#else
        // If we have a battery at all and it is less than 10% full, force deep sleep
        if (powerStatus2.getHasBattery() && !powerStatus2.getHasUSB() && batteryLevel->getBattVoltage() < MIN_BAT_MILLIVOLTS)
            powerFSM.trigger(EVENT_LOW_BATTERY);
#endif

This try-fix adopts the algorithm for battery low detection also for other platforms (ESP32). Hopefully, this will make the TBeam router mode usable.

[github-actions]

🤖 Pull request artifacts

file	commit
pr2444-firmware-2.1.10.3a5da73.zip	3a5da73

[PhilipLykov]

The fix didn't resolve the issue. My T-Beam v1.1 still hangs with ROUTER role. It works fine with ROUTER_CLIENT role.