Lilygo T3s3 E-Paper
The Lilygo T3S3 E-Paper offers as low power (on ESP32) of a device as you can get, suitable for running a mesh communication node. The paper display is easy to read and maintains images and text, even if the power is disconnected.
What can you do with it
The T3S3 E-Paper node’s easy to read display makes it a natural fit for devices that need to be able to communicate via LoRa, WiFi, or Bluetooth, while displaying something meaningful to the user.
I use mine as a base station for my ChatterBox cluster, as shown here. My base station is composed of a Lilygo T3S3 E-Paper running the ChatterBox mesh node firmware, an 86” Signal Plus omni-directional LoRa antenna, and a 20 watt bi-directional LoRa amplifier (amateur radio license required).
Good Things
Very easy to read display that keeps its state, even if the power is disconnected
Qwiic Connect Plug you can use for UART, I2C, or whatever else you want (except SPI). I use it for a realtime clock and/or GPS
Soldered SMA connector, which is vastly better than a flimsy pigtail connector
Small Form Factor - not much larger than the screen itself
ESP32 platform offers 4 MB of flash space and plenty of memory for most purposes
SD card reader for dependable IO and even more space
Many unused and accessible pins, if you need them
Not So Good Things
Screen is slow to update (~3 seconds) so you don’t want to be writing to it very often. For this reason, the ChatterBox firmware updates the screen no more than once every 90 seconds
Higher power consumption than some other platforms (non-ESP32). Of course, its still pretty low and if your solution needs at least 512k of memory, ESP32 is probably still a top option for you.
Few 3D Printable Enclosures - you might have to design your own, if you need an enclosure. Hopefully this will change soon.
Testing the T3S3 E-Paper
In order to test the T3S3 E-Paper and see how it performed as a mesh node, I installed the ChatterBox mesh node firmware, and onboarded the device to my local private cluster.
Over the course of months, I ran it as a base station, a solar node, with and without amplification, and more.
Video Demo
Rating: Excellent - Highly Recommended
Low Power Consumption
It’s based on ESP32 platform, which isn’t an extremely low power option, but the E-Paper display helps quite a bit, and if you add a realtime clock in lieu of GPS, you’ve got a good low-power mesh node.
Clear E-Paper Display
The paper display is extremely clear to read, and maintains the last display, even if power is disconnected. This means if your using this node for off-grid text communication and a message has been broadcast, but the node later loses power, it will continue to display the last message received - with no power. This could be quite important in some cases.
Great LoRa Performance
The Lilygo T3S3 E-Paper is an excellent option for the ChatterBox mesh node firmware. It has proven to be a stable and solid performer.
Easily Handles Encryption / ECDSA / Path Finding Algos
It has plenty of processing power and memory to perform encryption and digital signature operations. The integrated SD card reader allows as much storage space as you could possibly need for a mesh node.
Sliding On/Off Switch
The sliding on/off switch is perferred (in my opinion) over soft power switches offered by other devices.