feat(expander): default MCP INT output to active-HIGH in begin()#303
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JosipKuci merged 2 commits intoMay 19, 2026
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… polarity The MCP23017 power-on default for IOCON is 0x00 — which means INTPOL=0 (active-LOW): the INT pin drives HIGH when no interrupt is pending and only drives LOW when one fires. On Inkplate hardware (and any design that wires INT into a host MCU configured to wake on HIGH, e.g. ESP32 ESP_EXT1_WAKEUP_ANY_HIGH), this is exactly inverted from what is wanted, causing the host to see a permanently asserted wake line every time it sleeps. v11.0.1 restored the setIntOutput() API that v11.0.0 removed, but did not configure IOCON from begin(). This means each application that uses MCP- driven wake must remember to call setIntOutput() with the right parameters after display.begin(). For applications that don't, deep-sleep + MCP-driven wake is non-functional out of the box: the host wakes immediately on every sleep cycle regardless of pin activity. Call setIntOutput() from begin() with sensible Inkplate-correct defaults (active-HIGH, push-pull, ports not mirrored) so the library works correctly on standard Inkplate wiring without requiring application code to know about IOCON. Users with non-default wiring can still override by calling setIntOutput() after begin().
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On Inkplate 6 / 10 / 6PLUS the internal MCP23017's INT pin is wired to
an ESP32 GPIO that's used with
ESP_EXT1_WAKEUP_ANY_HIGHfor deep-sleepwake. The MCP power-on default for
IOCONis0x00(INTPOL=0,active-LOW) — meaning the INT pin idles HIGH whenever no interrupt is
pending. Result: ext1 wakeup fires immediately on every sleep call,
producing a continuous wake/sleep loop.
v11.0.1 restored the
setIntOutput()API (good) but doesn't call itfrom
begin(), so the library still doesn't work for deep-sleep wakeout of the box — every application has to know to call
setIntOutput()itself.Fix
Call
setIntOutput(PORTB, no-mirror, push-pull, active-HIGH)fromIOExpander::begin(). Applications with non-default needs can stilloverride after
display.begin().Verification
Inkplate 10 V1, arduino-esp32 3.3.7. Without the patch: device wakes
immediately every sleep cycle. With the patch: device sleeps for the
configured duration; ext1 only fires on real touchpad presses.
Compat / scope
Backward compatible — only changes a default; existing
setIntOutput()callers still win since they run after
begin(). File is gated toARDUINO_INKPLATE6 || ARDUINO_INKPLATE10 || ARDUINO_INKPLATE6PLUS, sono PCAL boards are affected.