In this project, I will show you how to build an awesome ESP32-based smartwatch with numerous environmental sensors and a laser that you can use to control all of your other projects remotely.
This is a truly awesome project, thanks for all your time and effort documenting it and sharing it .
The module itself at $190 is a real bargain - pity I am so far from the US.
May well think about wiring the money to my cousins there, they are thinking of travelling long haul this year. Even better plan, I could pay them by covering the same amount of their travel and subsistence travel costs while here - no need to enrich the predatory banks with their forex charges.
Really cool info, and I appreciate your kindness! It took quite awhile to design. I apologize shipping is an inconvenience, I’ve been looking to expand internationally but there are some things I need to figure out before I do. Maybe soon though! In the meantime I’m glad you enjoyed the article!
I believe it could! ESP32 is very versatile for network features, and I don't think the DStike has any external components beyond it. I know for sure beacon spamming would work since I got curious one day and tried it, but just know it'll drain the battery pretty quick.
Hello, I have some difficulties. I really want to be a paying member, but I can't make a paying subscription because I can't operate my bank card. I don't know what the expiration date and security code are.I'm a little sad.
I can't buy the same type of battery.can I use other similar 400mah batteries to replace it? I'm afraid this will cause problems 😭😭😭I'm not very good at this. I'm afraid I'll screw it up.
Sure! Just make sure it will fit inside the watch and that it is one cell. It is also okay if it’s not 400mah, the battery just won’t last as long. Good luck!
I've measured (or tried to measure) just about all those variables at some point, for both professional and personal projects.
At the moment I'm trying to measure Javelin throw distances to worst case errors of 1 cm. Am currently using physical means to survey the field I use, and involved in the slope measurement of the field, as that impacts the accuracy that a metal tape pulled along the ground can achieve.
A LIDAR with a range of only 4 m would go a long way to solving my problems.
I previously used a laser tape measure, to measure up to 25 m I seem to remember. I wasn't too impressed with its accuracy though, I got the feeling a metal tape pulled taut over a flat, hard surface was better. Though I could see 2 mm stretch, and 1 or 2 mm thermal expansion over a 40m travel with a metal tape (must measure its thickness now I think).
Your temperature readout of 31.38C tickles me.
That BME680 sounds quite a bit of tech. Pity that body heat puts up to a 5C shift on the temp..
I would never wear the module, I'd use it as a precision weather station, shield it from sun and wind like it should be. But then it will shift temperature reading slightly due to its own dissipation :
400mAh * 3.7 V / "the watch can last 14 hours" => 100 mW.
I tried Gemini.google on this (" use results with caution" :-D )
**what is the temperature gradient over a 2 cm by 2 cm by 1 mm piece of glass dissipating 0.1 W by natural convection**
=>
ΔT = q * L / k
ΔT ≈ (500 W/m²) * (0.001 m) / (1.1 W/(m*K))
ΔT ≈ 0.455 K
That sounds about right, also consistent with the 0.5C uncertainty I have with my own thermometer.
I have an ongoing contest with the resident pool "manager" where I swim. She has used a variety of floating alcohol pool thermometers, and now a thermocouple thermo with 5 m probe lead to get to the deepest part. All of them without exception read 1.5 to 2C higher than my own alcohol thermometer.
I've tried calibrating my own thermo, with a digital medical grade thermo (35 to 43C, stated accuracy of 0.1C) and with a small, wire-coil, home weather station (temperature and humidity), It is virtually impossible to calibrate to better than 0.5C accuracy. But all three thermos I have at home are close to 0.5C within each other.
I've also used three calibrated Fluke 289 multimeters with T/C probes stabilised in an ice bath - no matter how I moved the 2 probes between the 3 MM's, I could not get to the stated accuracy of the FL289, which was something like 0.2C I seem to remember.
So any temp measurement claiming accuracy of better than 0.5C I simply do not believe.
I worked on high temperature measurement systems in the steel industry, measuring up to prob around 800C. Also on jet engines. I think we were happy/lucky to get 10C accuracy there.
This is a truly awesome project, thanks for all your time and effort documenting it and sharing it .
The module itself at $190 is a real bargain - pity I am so far from the US.
May well think about wiring the money to my cousins there, they are thinking of travelling long haul this year. Even better plan, I could pay them by covering the same amount of their travel and subsistence travel costs while here - no need to enrich the predatory banks with their forex charges.
Really cool info, and I appreciate your kindness! It took quite awhile to design. I apologize shipping is an inconvenience, I’ve been looking to expand internationally but there are some things I need to figure out before I do. Maybe soon though! In the meantime I’m glad you enjoyed the article!
AMAZING!! Thank you so much for making this so in-depth!!
Thanks so much for reading! :)
That is really impressive
Thanks for open source
Could the functionality of the DStike watch be programmed into this one for testing wifi networks?
I believe it could! ESP32 is very versatile for network features, and I don't think the DStike has any external components beyond it. I know for sure beacon spamming would work since I got curious one day and tried it, but just know it'll drain the battery pretty quick.
Best,
Justin
Hello, I have some difficulties. I really want to be a paying member, but I can't make a paying subscription because I can't operate my bank card. I don't know what the expiration date and security code are.I'm a little sad.
Hi! Sorry to hear that, but thanks for your support anyway!
I can't buy the same type of battery.can I use other similar 400mah batteries to replace it? I'm afraid this will cause problems 😭😭😭I'm not very good at this. I'm afraid I'll screw it up.
Sure! Just make sure it will fit inside the watch and that it is one cell. It is also okay if it’s not 400mah, the battery just won’t last as long. Good luck!
I've measured (or tried to measure) just about all those variables at some point, for both professional and personal projects.
At the moment I'm trying to measure Javelin throw distances to worst case errors of 1 cm. Am currently using physical means to survey the field I use, and involved in the slope measurement of the field, as that impacts the accuracy that a metal tape pulled along the ground can achieve.
A LIDAR with a range of only 4 m would go a long way to solving my problems.
I previously used a laser tape measure, to measure up to 25 m I seem to remember. I wasn't too impressed with its accuracy though, I got the feeling a metal tape pulled taut over a flat, hard surface was better. Though I could see 2 mm stretch, and 1 or 2 mm thermal expansion over a 40m travel with a metal tape (must measure its thickness now I think).
Your temperature readout of 31.38C tickles me.
That BME680 sounds quite a bit of tech. Pity that body heat puts up to a 5C shift on the temp..
I would never wear the module, I'd use it as a precision weather station, shield it from sun and wind like it should be. But then it will shift temperature reading slightly due to its own dissipation :
400mAh * 3.7 V / "the watch can last 14 hours" => 100 mW.
I tried Gemini.google on this (" use results with caution" :-D )
**what is the temperature gradient over a 2 cm by 2 cm by 1 mm piece of glass dissipating 0.1 W by natural convection**
=>
ΔT = q * L / k
ΔT ≈ (500 W/m²) * (0.001 m) / (1.1 W/(m*K))
ΔT ≈ 0.455 K
That sounds about right, also consistent with the 0.5C uncertainty I have with my own thermometer.
I have an ongoing contest with the resident pool "manager" where I swim. She has used a variety of floating alcohol pool thermometers, and now a thermocouple thermo with 5 m probe lead to get to the deepest part. All of them without exception read 1.5 to 2C higher than my own alcohol thermometer.
I've tried calibrating my own thermo, with a digital medical grade thermo (35 to 43C, stated accuracy of 0.1C) and with a small, wire-coil, home weather station (temperature and humidity), It is virtually impossible to calibrate to better than 0.5C accuracy. But all three thermos I have at home are close to 0.5C within each other.
I've also used three calibrated Fluke 289 multimeters with T/C probes stabilised in an ice bath - no matter how I moved the 2 probes between the 3 MM's, I could not get to the stated accuracy of the FL289, which was something like 0.2C I seem to remember.
So any temp measurement claiming accuracy of better than 0.5C I simply do not believe.
I worked on high temperature measurement systems in the steel industry, measuring up to prob around 800C. Also on jet engines. I think we were happy/lucky to get 10C accuracy there.