Build and push server image / build-and-push (push) Successful in 35s
Factory-reset (GPIO3, hold 10s): clears stored WiFi/server config and restarts into provisioning -- the deliberate, USB-free replacement for the earlier reverted RST-based auto-reprovisioning idea. Next-photo (GPIO2, tap): wakes the device and forces the server to advance immediately via a new POST /frame/advance, instead of waiting for the refresh interval. Both buttons arm themselves as deep-sleep GPIO wakeup sources so a press is noticed promptly even while asleep. Also makes GET /frame/image side-effect-free: it now only advances once refresh_interval_s has elapsed since the current photo was set (tracked server-side), so a device reboot for any reason just redisplays the current photo instead of silently skipping ahead. The server maintains a small reorderable upcoming-photos queue, viewable and rearrangeable from the web UI.
69 lines
3.1 KiB
Markdown
69 lines
3.1 KiB
Markdown
# Hardware
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## Parts
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- An ESP32-C6 dev board (e.g. ESP32-C6-DevKitC-1). Needs 8MB flash --
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see [`firmware/sdkconfig.defaults`](../firmware/sdkconfig.defaults) and
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[`firmware/partitions.csv`](../firmware/partitions.csv) if yours differs.
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- [Waveshare 7.3" E Ink Spectra 6 (E6) panel](https://www.waveshare.com/7.3inch-e-paper-hat-e.htm) --
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800x480, 6-color, SPI.
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- A USB cable for flashing/power.
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## Wiring
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The panel connects over SPI plus three control lines (data/command, reset,
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busy). Defaults below match the reference build and are set in
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[`firmware/components/epd7in3e/Kconfig`](../firmware/components/epd7in3e/Kconfig) --
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override via `idf.py menuconfig` under **E-Paper Display (epd7in3e)
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Configuration** if your wiring differs.
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| Panel pin | ESP32-C6 GPIO | Kconfig option |
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| --------- | ------------- | ----------------- |
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| CLK | 20 | `EPD_PIN_CLK` |
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| DIN | 19 | `EPD_PIN_MOSI` |
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| CS | 18 | `EPD_PIN_CS` |
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| DC | 9 | `EPD_PIN_DC` |
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| RST | 10 | `EPD_PIN_RST` |
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| BUSY | 11 | `EPD_PIN_BUSY` |
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| VCC | 3.3V | -- |
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| GND | GND | -- |
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Optionally, two buttons, both wired the same way -- momentary push button
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between the GPIO and GND, no external resistor needed (the firmware
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enables each pin's internal pull-up, so it idles high and reads low when
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pressed):
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- **Factory-reset (GPIO3)**: held for 10 seconds, clears the stored
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WiFi/server config; see
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[`firmware/README.md`](../firmware/README.md#resetting-to-provisioning-mode).
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- **Next photo (GPIO2)**: a normal press skips immediately to the next
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photo; see
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[`firmware/README.md`](../firmware/README.md#skipping-to-the-next-photo).
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Both pins were picked because they're within GPIO 0-7 -- the only pins
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the ESP32-C6 can wake from deep sleep on -- aren't strapping pins, and
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aren't already used by the panel wiring above.
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A couple of things worth knowing if you pick different pins:
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- **Avoid the ESP32-C6's strapping pins** (GPIO 4, 5, 8, 9, 15) and the
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USB-JTAG pins (12, 13) where possible -- strapping pins are sampled at
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reset to select boot mode. The reference wiring above already uses
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GPIO9 for DC, which *is* a strapping pin; it's only sampled during
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power-on/reset, so it's safe once the app is running, but if
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flashing/boot ever misbehaves on your board, check whether the panel is
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pulling that line low during reset.
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- The panel's SPI interface is rated well above the firmware's default
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4MHz clock (`EPD_SPI_CLOCK_HZ`), but breadboard/dupont-wire connections
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are often unreliable much past a few MHz. Raise it once your physical
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wiring is confirmed solid.
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## Power
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The device spends nearly all its time in deep sleep, waking briefly once
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an hour (configurable, see the server's web UI) to fetch and display a
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photo. A full-color refresh on this panel takes 15-30+ seconds and draws
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more current than deep sleep by a wide margin -- expect battery life (if
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not running from USB power) to be dominated by refresh frequency, not
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sleep current.
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