From b10690f16d2b310221ffa7995e779f09d146f7f8 Mon Sep 17 00:00:00 2001 From: Sadeep Madurange Date: Mon, 5 Jan 2026 13:52:16 +0800 Subject: Tighten etlas prose. --- _log/etlas.md | 33 +++++++++++++++------------------ 1 file changed, 15 insertions(+), 18 deletions(-) (limited to '_log') diff --git a/_log/etlas.md b/_log/etlas.md index 9e2d191..7c50c72 100644 --- a/_log/etlas.md +++ b/_log/etlas.md @@ -20,20 +20,20 @@ DHT22 sensor. -Stocks: Two weeks EOD prices from Polygon.io (max SRAM holds). Flask app on VPS -relays feed, lets me swap symbols via config. FastCGI + httpd + htpasswd. +Stocks: Two weeks EOD prices from Polygon.io (max possible). Flask app on VPS +relays feed; manages watchlist. Backend: httpd + htpasswd + FastCGI + Flask. -gui_plot_stocks() triggers WDT. vTaskDelay() prevents that. Stepped graph was -easier to code for the bit-packed framebuffer (not enough memory for much -else), but it's messy--too messy. - -Note to self: Refactor gui_plot_stocks(). Bresenham’s line algorithm perhaps? +gui_plot_stocks() triggers watchdog; vTaskDelay() required. Stepped graph was +easier to implement (under memory constraints), but the logic is hideous. Note +to self: Refactor with Bresenham’s? News: Channel NewsAsia RSS. MCU parses XML directly. Character glyphs stored as -bitmaps in sprites directory. +bitmaps in header files. -Weather: DHT22 via PWM. 26µs/50µs/70µs pulses too fast for standard ESP32 APIs. -Compare relative pulse widths: +Weather: DHT22 single-wire protocol. 26µs/50µs/70µs pulses are too fast for +standard ESP32 APIs. Bit-banged relative pulse widths: (Ported from ESP8266): ``` static inline int dht_await_pin_state(int state, int timeout) @@ -91,15 +91,12 @@ static inline int dht_get_raw_data(unsigned char buf[BUFLEN]) } ``` -Ported from ESP8266. - -After flashing new versions, display would stop responding. Didn't observe this -with e-reader. Issue occurs spontaneously. Couldn't find root cause. Making a -change like adding a comment or tweaking delay in refresh() (then changing -back) fixed it. Noisy electrical connections? +Ghost in the machine: epd_init() stalls intermittently on first refresh() after +flash. Toggling delay values in refresh() resolves it. If first refresh +succeeds, it remains stable. Root cause unknown--suspected power supply issues +from powering display via MCU. -Once running, it runs: August 2024 - December 2025. +Uptime: August 2024 - January 2026 Commit: [a92c86a](https://git.asciimx.com/etlas/commit/?id=a92c86ac1592c2137d3d1fec1668eacc2d0ca581) -- cgit v1.2.3