LILYGO® T-Watch S3 open-source smartwatch with LoRa and ESP32 US915 Mhz

Firmware: Silver (K221)

Pickup available at 2251 NW 41st Street

Usually ready in 1 hour

T-Watch S3 is an open-source smart watch for developers who want to experiment with LoRa and ESP32 S3 technology in wearable devices. It is highly customizable and usable in a variety of applications.

US 915 MHz


Platform Arduino-IDE, ESP-IDF, VS Code, Micropython

Wi-Fi: 802.11 b/g/n

Bluetooth: BLE V5.0

Onboard Functions RTC, Microphone, MAX98357A, Power Detection, BMA423 3-axis acceleration sensor
DRV2605 Haptic Driver Motor for ERM and LRA
AXP2101 Highly Integrated Power Management Unit
 SX1262 Low Power LoRa Transceiver
This version supports US 915 Mhz


Sample Code For Reference [Github]

If you need technical support please check below link to find more details.


T-WATCH-2020 document

Micropython ESP32 Firmware Download Address

Pin Diagram

  • 1 X T-Watch
  • 1 X Cable

Dev Watch Return Policy

Open Source watches are specialty items that generally cannot be resold on return, especially if the firmware has been flashed. Defective units can be replaced or returned for refund within 30 days of purchase. Non-defective units can be returned in the same time frame if in like-new condition with a 20 percent restocking fee applied. If the unit has had altered firmware or became bricked due to a non-standard firmware flash, the board may not be eligible for return.

Sales tax is required in many states and will be added at checkout if applicable to your delivery state. Tax exempt forms can be sent to our support department.

Shipping & Returns
FREE Standard shipping on all items shipped in the USA! 
We are in Florida and ship to: USA, Australia, Austria, Canada, France, Germany, Israel, Netherlands, and the United Kingdom. Local pickup available in Gainesville, FL

Expedited shipping orders placed before 3PM EST weekdays will ship that day. Standard shipping orders ship within 1 business day.

Sales tax: shipments shipped to states in which we are registered to collect tax will have appropriate tax added at checkout. Tax exempt forms can be sent to our support staff who can activate exemption status. 

Lost packages and insurance

International Shipping:

Shipping options are visible in cart by using the shipping estimator. Transit times posted are estimates. International packages are subject to customs holds and duty payment may be required by your government on delivery. The cost of duty  is not reimbursable. Internatonal shipping charges are not refundable in the event of a return.


See item description for product specific return policies, and return policies vary by item.

Bulk/High Value Order Returns

Due to the labor required to package and ship bulk orders, as well as cost and stock issues involved in replenishing items, bulk orders of 5 pieces or more are not returnable unless the equipment is defective or mis-advertised, or a return period is prenegotiated. For non-defective returns over $500, a restocking fee may be deducted from the refund to cover bank or card processing fees.


Items on backorder or preorder will ship as estimated on the item page. You can cancel an order any time up until shipment. Orders with expedited shipping will arrive in the advertised time after the order ships, not after the order is placed.


If you want to cancel an order, please email or call us at (352) 372-9902. If your item has not been shipped, we will cancel the order and provide a full refund.

Firmware: Silver (K221)

Customer Reviews

Based on 3 reviews

Im surprised these are still in stock. I use them as trackers for my kids lol. Great product to stay meshed.

Joshua Harris
What I was looking for, however I have some qualms with the listing itself, not the product.

Note, If this review doesn’t make any sense to you, this is not the watch for you! This product is a dev kit intended for people willing and wanting to write the code to make the bare hardware work. This is not a functional consumer product out of the box. If you do know what youre looking for, hopefully my review can help clarify things.

Buyers should note that the S3 version is not compatible with the software for other versions of the LilyGo T-Watch, and the GitHub linked in the description is not accurate.
While it shares some characteristics with the 2020v3, it uses a different chipset and instruction set. The two are not compatible, and the S3 has much less community support as of this writing,

The T-watch-S3 uses an ESP32S3 MCU with 16Mb flash, 8Mb PSRAM , Sx1262(LoRa transceiver), AXP2101 power management unit, and an IR emitter diode. The esp32s3 uses Xtensa® Dual-core 32-bit LX7 running at 240MHz utilizing the RISC-V Microprocessor instruction set and requires esp-idf version 4.6 or greater to build for. The biggest difference is this chip lacks support for an SD card and has more available GPIO pins (45). The pinouts are different between these two watch models.
The GitHub repo for that particular branch is to match This watch* can be found here. (Or, if using the git cli utility: git clone –branch t-watch-s3 )

The T-Watch2020v3 That this watch closely resembles uses a ESP32-D0WDQ6-V3 MCU with 16Mb flash, SRAM 520 kB SRAM / PSRAM 8MB, AXP202 power management unit, also has the IR Diode, but does not have the Sx1262 LoRa chip. The ESP32-DOWDQ6V3 also uses the Xtensa® Dual-core 32-bit LX7 chipset running at a clock rate of 240MHz. This watch does include SD card support, however it lacks the same number of available pins(22).
If you find a good deal on the 202v3, This software for it is excellent. However, it is not compatible with this watch listing. GitHub - sharandac/My-TTGO-Watch: A GUI named hedge for smartwatch like devices based on ESP32. Currently support for T-Watch2020 (V1,V2,V3), T-Watch2021, M5Paper, M5Core2 and native Linux support for testing.

This Needs to be made clear in the listing as physically the devices look identical and in fact use the same casing and strap. At the very least the links for the firmware need to be updated.

Jason Agne
a good watch

Previously left a review about the watch battery running out but discovered the wifi disconnect needed a 'true' passed in to also turn it off or it would drain the battery.

However, I was trying to get it to mimic a 433MHz garage door opener and the spectrum analyzing code on github doesn't seem to function at all, or the radio doesn't - but that's not really what I got the watch for so I didn't exactly try hard.

Battery life will vary based on WiFi and Bluetooth connections and how long the screen is on. Based on factory firmware testing, with a battery voltage of 4.1V~4.2V, the screen is observed every 2 hours, displaying for approximately 15 seconds before automatically resting, the standby battery life is approximately 48 hours. Our team has reached out to you via email to confirm how the watch is being used.