PIO-ESP32-Rememberall

The Rememberall - equipped with a WS2812 LED ring and a ePaper display - will help you keeping track of easily forgotten events.
The project includes a PowerShell based feeder script which allows you to load events from multiple iCal calendar files (or URLs, in example google calendars), find the next upcoming event and send the processed data to your MQTT broker where the Rememberall will pick it up.
The Rememberall supports 2 types of "active reminders", a "cosy" reminder which shows a slow light wave on the LED ring, and a more agressive reminder with a faster frequency.
Note: This project requires a NTP server (either local or internet).

Design Goals

The Rememberall has been designed to run on a WEMOS S2 Mini plugged in a ESP-Mini-Base. The whole setup is powered by a single LFP cell (in my case two 32700 round cells in parallel). To maximize battery lifetime, the code has been designed put the ESP in DeepSleep as much as possible and also reduce power usage by enabling WiFi only from time to time to check für updates. To further reduce power requirements, the ESP's CPU clock has been limited to 80MHz (see platformio.ini). The code is based on my PIO-ESP32-Template, also consult the readme in that repo for requirements and flashing guide.

Hardware

• WEMOS S2 Mini
• ESP-Mini-Base (optional)
• WaveShare GDEW0213Z16 2.13" 3-color ePaper display
• WS2812 RGB LED-Ring with 32 LEDs (AliExpress, Amazon etc.)
• Non-latching Pushbutton and LED (both optionally)

Note: The ESP-Mini-Base is optional. If you do not plan to use it, you have to take care of:

• Reading VCC (external attenuator 12k / 3k6 voltage divider, 100nF ceramic capacitor recommended on ESP ADC pin)
• ability to power off LED ring (draws quite some current when off (show black), which would also be drawn during DeepSleep)

MQTT Topics

All MQTT topics mentioned below need to be set retained, as the Rememberall requires all of them to be fetched at startup.

/Your/Topic/Tree/eventTxt

This topic contains the text to be displayed on the ePaper display. It may contain 1, 2 or 3 lines of text and needs to be formatted like this (example for 3 lines of text):
LineCount|ColorLine1;TextLine1|ColorLine2;TextLine2|ColorLine3;TestLine3
The LineCount must be an integer of 1-3 indicating how much text lines the message contains. ColorLineX is the text color (per line), where 0 equals black and 1 equals red.
Attention: The characters | and ; must not be used in the Summary field (description) of your calendar events, as they are used as seperators. If you are using the provided PoSh feeder, the first word of the Summary field will be used to describe the event. Note that the text will be truncated to 10 characters, which can be displayed per ePaper line.

/Your/Topic/Tree/eventReminder

This topic contains the deadline (which equals to the start date of an event), the start time of the 2 reminder periods and the color which the LED ring should show for the current event. DeadLineEpoch|CosyReminderStartEpoch|AggroReminderStartEpoch|RGB-Color
Example:
65ab999f|65aa481f|65aaf0df|0xFF00FF
Timestamps are encoded in Unix Epoch time and in hexadecimal base to shorten the strings. The LED color is encoded as 0xRRGGBB.
Note: You should use powerful colors, i've experienced that bright colors tend to look like white on the ring.

/Your/Topic/Tree/Status

This topic is basically used as a "reminder flag" for the Rememberall. You can use the button on the Rememberall to acknowledge the current event (double click on the button), where the following will happen:

• Rememberall sets the Status topic to ack (retained)
• Rememberall stops reminding by disabling the LED ring and clearing the display
• Rememberall will go to sleep for WIFI_SLEEP_DURATION (30 minutes by default)
• The feeder script will skip reminders for this event and adopt SleepUntil accordingly

Configuration

Beside the basic build / flash configuration described in the PIO-ESP32-Template README, you will need to configure:

include/time-config.h

Setup your desired NTP server as NTPServer1, optionally add a second one.

include/user-config.h

This file contains all configurable options for this project like

• type/wiring of ePaper display
• type/wiring of LED strip/ring/whatever
• default WiFi sleep time
• MQTT settings
• FastLED animation settings and global brightness for reminders

The file should be well commented.

The Feeder Script

The PoSh feeder script is designed to be run as a scheduled task once every hour (preferrable at 0 minutes). The script is (hopefully) well documented and should be adopted for your needs in the Configuration Settings section. It will handle regular and recurring events, filter the first event from all configured calendars and parse it for the Rememberall according to your configuration.
Note that it requires 2 external libraries for MQTT communication and iCalendar handling:

• IcalVCard / NuGet package
• M2Mqtt / NuGet package

Place the 2 DLL files in a lib subdirectory of the place where the feeder script resides.
Note: In order to make the german "umlauts conversion" work correctly, you need to make sure that the script is saved UTF8-BOM encoded locally.

Pushbutton functions

The (optional) pushbutton has 3 functions:

• Short Press: Skip current active reminder period by sleeping for BUT_SLEEP_DURATION (defaults to 6hrs)
• Double Click: acknowledge the current event as described above
• Long Press: Toggle WiFi up/down (useful e.g. for OTA-flashing)

Note that the pushbutton will not wake the ESP while in DeepSleep, so the button will only react during active reminding periods.

Photos

Here are 2 photos from my Rememberall:

Front	Back

Changelog

v1.0.1

• Minor code changes (final MQTT topic tree, external button)
• Feeder script encoding fixed
• Added fotos of finalized hardware
• Updated Readme

v1.0.2

• Bugfix: WiFi did not wake up after WIFI_SLEEP_DURATION
• Updated readme with pushbutton functionality

v1.0.3

• Improved Feeder script; now adds multiple words (one word per ePaper line) from the summary field of the event (up to 3 lines which can be showed on the ePaper display)
• Feeder script has a new "WhatIf" switch parameter for testing (prints what would be sent to the MQTT broker)

v1.0.4

• Changed button behavior
• Added ability to "skip" an active reminder period with a single button click (just sends ESP to sleep for 6 hours)
• Minor bugfix in Feeder script
• Bugfix: ESP did not clear the screen after elapsed events when a valid SleepUntil was set

Have fun,
Juergen