iTechGuides is reader-supported. When you buy through links on our site, we may earn an affiliate commission. As an Amazon Associate I earn from qualifying purchases. Learn more
A low-cost M6 smart fitness band can be more than a sealed tracker—but only if its particular board exposes hardware you can reach and its firmware can be replaced. In a 2021 project, Raphael Baron opened one AliExpress-bought M6, identified a Telink TLSR8232, dumped its stock flash over the chip’s SWire interface, and built custom firmware that used the screen and Bluetooth Low Energy (BLE) radio to display readings from a separate soil sensor. It was a hardware-specific repurposing project, not a validated fitness-band upgrade.
What this M6 project actually changed
Baron’s stated goals were to understand the band’s hardware, communicate with it, dump its stock firmware, and run custom code using its GPIO pins, color display, and BLE. His July 6, 2021 project report documents a single unit he purchased from AliExpress. Hackaday’s July 8, 2021 summary describes the outcome as firmware that read BLE soil-moisture sensors used for the author’s plants.
That M6 is not the Xiaomi Mi Smart Band 6. The similar names do not imply shared hardware: the author’s comparison of the two was about naming and historical price, not compatibility. He said he paid around $6 for his M6 in 2021 and cited roughly $50 for the Xiaomi device at that time; neither figure is a current price.
PC Slower Than It Used to Be?
A free scan shows the junk files, broken settings and background clutter dragging Windows down - then fixes them in one click.Free scan · Windows 10 & 11Crashes, No Sound, or Screen Glitches?
Random freezes, missing sound and display glitches usually trace back to one bad driver. Find and replace yours safely.Free scan · under a minute“M6” is a generic product name used on different listings, and the report does not establish a standard board shared by every M6-branded band. The findings below describe Baron’s examined variant. A similar-looking listing—or a low price—does not confirm that it contains the same chip, display, or programming pads.
#1 Best Overall
- Perfectly designed for Mi Band 5 and Mi Band 6 - Our bands are made specifically to fit Xiaomi Mi Band 5 and Mi Band 6 snugly and securely, ensuring you get the best possible experience from your wearable.
- Made of soft TPU material - Our bands for Mi Band 5 and Mi Band 6 are crafted from premium-quality, ultra-soft TPU material that feels comfortable on your skin and won't irritate even after hours of use.
- Variety of colors to choose from - We offer a range of fashionable and versatile colors to suit your individual style. Mix and match to create the perfect look for any occasion.
- Easy to install and remove - Our bands are designed with easy, hassle-free installation and removal in mind, so you can effortlessly switch up your look whenever you like.
- Durable and long-lasting - Our bands are made to last, with high-quality TPU material that is resistant to wear and tear. You can enjoy wearing your Mi Band 5 or Mi Band 6 for longer periods of time without worrying about its longevity.
What hardware was inside the examined band?
Baron reports finding a Telink TLSR8232, a 0.96-inch diagonal 160×80 color display, an approximately 100 mAh LiPo battery, and a vibration motor. He suspected the heart-rate sensor was fake; that is his assessment, not an independently verified teardown result or a test of sensor accuracy.
In the project report, the TLSR8232 is described as a 32-bit tc32-family chip running at 24 MHz, with 16 kB of SRAM, 512 kB of internal flash, BLE, and a single-wire serial interface called SWS or SWire. These are the report’s specifications for the chip in this unit, not assurances about other M6 products.
The case came apart easily in Baron’s experience. He questioned the IP67 claim printed on its box, but did not establish water resistance with a test. Opening this unit without much difficulty should not be taken as evidence that every M6 case opens the same way or that the band is waterproof.
Rank #2
- 【Compatible Model】Width of the band is 16mm. Compatible with HENGTO 1.4''/MorePro HM08/FITVII HM08/YOUSOKU H97 Pro/Amzhero D26/HENGTO H39 PLUS Fitness Tracker Watch (H39Plus).
- 【Material】Made of premium silicone material, light weight , soft and comfortable to wear, Also it is durable, Metal buckle clasp provides a simple yet elegant look.
- 【Band Sizes】It fits 5.5"-8.7"(band length:87+112mm), Precise multiple alternative holes allow your watch adjust the suitable size, with comfortable touch feeling on your wrist.
- 【Easy Installation】Upgraded and improved-built quick release pins feature a stable and reliable performance, very easy to install and disassemble, no falling off or loose issue, fit perfectly.
- 【After-sale Service】We provide friendly after-sales service. We are free to replace it or make a refund for you if there is any quality problems, please feel free to contact us.
How did the author access the firmware?
Map the board before connecting a programmer
Baron used a multimeter and the chip datasheet to identify exposed board pads. The key interface was Telink’s SWire/SWS connection, which provided access to the chip for debugging and programming. The project’s central challenge was not simply finding a firmware file: it was making a working connection to a low-level interface whose timing and command behavior were not fully clear from the available documentation.
Make SWire timing and reset work
Baron describes SWire as asynchronous and half-duplex, with the programmer and target needing compatible timing. His account works through command and data framing, read and write operations, and a speed-control register. In some cases, the CPU would not respond until he reset it and sent CPU-stop commands. The board did not provide reset at a convenient exposed pad, so reaching the reset pin required delicate soldering.
That is the author’s procedure on his board, not a universal recipe for all TLSR8232 devices. Pad layouts, reset access, and timing may differ between boards; a wiring assumption based on the M6 name alone risks damaging the device.
Rank #3
- Keep Your Wrist Free: This arm band for Google Fitbit Air offers an alternative when wrist wear gets in the way at work or during daily tasks. Wear your tracker on your upper arm to keep your wrist clear while going about your day.
- Lightweight, Low-Profile Design: The slim nylon band keeps bulk to a minimum for everyday wear. It fits discreetly beneath suitably loose sleeves, giving you a less visible way to wear your tracker while keeping your wrist free.
- Easy Fit Adjustment: The hook-and-loop closure lets you fine-tune the fit for everyday wear. Made from lightweight, non-stretch woven nylon, the band comes in M and L sizes; choose according to the listed circumference range.
- Ankle Wear as an Option: Alongside upper arm wear, the band can be worn around your ankle within its listed size range. Its low-profile design fits beneath suitably loose pant legs, offering another placement for your daily routine.
- Everyday to Nighttime Wear: An alternative for evenings at home and nights when you prefer nothing around your wrist. The hook-and-loop closure makes the band easy to put on and remove. Includes one replacement band; tracker not included.
Use an alternative programmer and preserve the stock image
Rather than rely on the tooling he initially encountered, Baron built an alternative programmer around an STM32 Blue Pill development board and used a Python client. Through SWire he controlled the SoC’s internal flash interface and reported saving a 512,000-byte dump of the stock firmware. Keeping that original image is a useful preservation step before experimenting, although the report does not establish that every unit can be restored from a dump using the same process.
The Tool Desk
Outbyte PC Repair FREERepair Windows errors before they cause bigger problemsFix Now →Outbyte Driver Updater FREEScan for outdated or missing drivers - takes under a minuteDriver Scan →For custom code, he used Telink’s TLSR8232 SDK and a tc32 toolchain packaged in Docker. This is an embedded-development workflow: access to the chip and a build environment are prerequisites, not an ordinary settings-menu option. The project illustrates why “flash custom firmware” here means working with board-level connections, a specialized interface, and a compatible compiler rather than installing a normal wearable app.
What did the custom firmware demonstrate?
GPIO and the capacitive button
Baron first demonstrated basic GPIO control with a blinking output, then investigated the touch input. He identified the capacitive button input as GPIO_PC2 on his examined board. That pin assignment is specific to this variant and should not be used as a guaranteed map for another M6.
Rank #4
- 【Trail Running and Outdoor Activity】Real-time pace tracking on uneven terrain. Distance covered, vertical gain, and active minutes logged per session. Lap memory for interval splits. 170+ sport modes include trail running, ridge scrambling, and outdoor adventures. Adjustable silicone band fit.
- 【Bluetooth Calling, Messages, and Music Control】Make and receive calls from your wrist. Send quick text replies, control music playback, take photos remotely from your phone. Compatible with iPhone (iOS 9.0+) and Android (5.0+) via Glory Fit Pro app. Calendar reminders and message alerts.
- 【Activity Tracking and Smart Reminders】Logs daily steps, distance, calories, pace, and active minutes per session. Sleep duration tracking. Stand reminders, water intake reminders, and step goals. Activity data stored 30 days. Sync to Glory Fit Pro app for iPhone and Android.
- 【5ATM Waterproof and 1.43" AMOLED Display】Certified for 50-meter static water pressure. Suitable for swimming laps, rain, sweat, shower, and creek crossings. 1.43" AMOLED at 1000 nits provides readable display in direct sunlight. Optional Always-On Display. Adjustable brightness.
- 【15-Day Battery and 2-Year Warranty】400mAh lithium-polymer battery up to 15 days typical use, 5-7 days with Always-On Display active, or 60 days on standby. 2-hour full charge via magnetic charging cable. 2-year manufacturer warranty. A thoughtful birthday, Father's Day, anniversary, or Christmas gift idea for runners, lifters, triathletes, and gym athletes.
Display control
The band’s 160×80 screen is an SPI TFT driven through an ST7735 controller. Baron mapped the display signals and wrote firmware to draw to it. The display was the key output for the later sensor demonstration: instead of trying to make the stock interface do something it was not designed for, he used custom code to turn the screen into a small readout.
BLE peripheral and central roles
The custom firmware demonstrated the band in both BLE roles. In peripheral mode, it exposed a service whose value could be written to toggle an LED. In central mode, it listened for broadcasts from a b-parasite soil sensor, recognized the device address, decoded battery voltage, temperature, humidity, and soil-moisture fields, and rendered readings on the display.
Recommended Free Tools
The notable result was a tiny sensor console on a wrist-worn screen. The b-parasite was separate sensor hardware; it was not part of the band, and the demonstration did not validate the band’s stock heart-rate or other fitness measurements.
Best Value
- 👀 [GREAT VIEWING] BoxWave Holster Compatible With FiiO M6. New design integrates a SAFE AND SECURE holder with minimal screen coverage. No plastic window cover that obstructs your view or operation of the device. 💬 Includes limited 3rd party tech support for your device (up to 3 inquiries via messaging) - not affiliated with or endorsed by FiiO ⭐ *** PLEASE NOTE, M6 DEVICE NOT INCLUDED ***
- 📏 [ADJUSTABLE] Fits your device as well as many other devices while remaining secure. The ActiveStretch Sport Armband's innovative design uses strong ELASTIC GRIPS to tightly grip your device securely to allow full viewing and access while keeping it in place.
- 💃 [FLEXIBILITY] Rotate 360 degrees to view your device at the PERFECT ANGLE. Click into one of 23 pre-set positions without removing it from your arm!
- 📦 [EXTRA STORAGE] Includes key slot for SAFE STORAGE while you are out and about.
- 👕 [BUILT FOR COMFORT] Breathable and stretchable material with cutouts on the armband for added VENTILATION and circulation.
What to check before attempting the same hack
There is no reliable compatibility verdict from an M6 listing title alone. Before buying or opening a band for this project, look for evidence about the specific board and the development path:
- SoC identity: confirm the board contains a Telink TLSR8232 rather than assuming all M6-labelled bands do.
- Programming access: determine whether SWire pads are present and whether reset can be reached safely.
- Display: check the panel resolution, controller, and signal wiring; Baron’s ST7735 mapping applies to his unit.
- Software: account for the TLSR8232 SDK, tc32 toolchain, programmer hardware, and client software needed for this approach.
- Physical access: inspect how the case is assembled and consider whether opening it could damage the device or any seals.
The project report is the detailed source for Baron’s hardware and workflow; Hackaday’s summary corroborates the soil-sensor result. Neither source is an independent fitness-accuracy, medical, battery-life, durability, or water-resistance evaluation.
Quick Recap
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
