I am currently trying to make a bicycle helmet smarter by adding GPS and GSM modules on it so that the helmet can contact the emergency services in case of any accident detected by the accelerometer.
Although I have some theoretical experience with sensors and microcontrollers, I have little practical experience. Hence, I was hoping to get some tips for this project, for example,
Modules - Provided, I want to use this in Sweden. Which GSM module to use? Which GPS module to use? How to detect impacts, current idea is to use an accelerometer?
Microcontroller - For prototyping, I am thinking to use Arduino uno, but in the future, all these components should fit on the helmet. What microcontroller is used for such compact products? And is a custom PCB the way to go for compactness?
Power consumption - Do these modules consume a lot of power? Which power supply shall be used, thinking about the size and also the number of hours it can work without charging?
Feasibility - Is this plan feasible, is having all these modules and power supply close to the head, harmful or it is not critical?
I think Europe is going to use 2G networks for some time. You can use any 2G module, SIM800L or SIM800C. If you go for 3G, you can use SIM5300E
I recommend to use a internal GPS device for this application. Like SIM39EA or Telit SE868 kind of devices.
Accelerometer , i recommend MMA8452 as its having 12bit resolution and breakout boards are available for experimentation.
I use STM32L in my designs as ST keeps all MCU upgrades footprint compatible, even the software drivers too.
Yes, obviously you have to go for a custom PCB.
Yes, GSM consumes more power when transmitting. You have to design such that you keep everything turned off when not needed.
Yes, it will work. The radiations effect if GSM module is always turned on. If you only turn them ON when accident occurs, then there is no problem.
All these features are already implemented in my VALTRACK-V2 design. You can make use of it.
Yeah, It can be delivered.
Rs.4000/- for sample
Rs.2500/- for > 100 nos
Rs.1500/- for > 1000 nos
Yes you can program threshold using an Android app by bluetooth. It can send alert by SMS
It works with a LiPo battery or on external 5V to 12V source as well.
Yes, you need to custom firmware according to your application.
Right now the device already works in SMS alert mode , when motion detected it sends a SMS with location. It should work straight out of the box for you.
Is there an app that will come along with Valtrack? What features can be modified through this app?
Can you give an estimate of the mAh I should go for if I want it to run for let’s say 8-10 hours of usability between charging cycles? I would like to light up some LEDs using this source as well. And I understand it might depend also on whether the GSM is used for transmitting during this time. But, to get an idea, how much power do they consume when not in use?
Can you elaborate on how to make the system turn off or sleep when not in need?
Also, the SMS with location will be sent to which number? How do I modify that?
I have tested VALTRACK to run for 72 hours at 1 minute HTTP ping intervals on 4000mAh battery.
The current consumption can be reduced to almost zero when not in use.
This video is an example
You need to turn off the devices when not in motion , We can customize firmware if you need as per your requirement.
You can also buy source code and the hardware design also if you want to customize yourself.