[Bangle.js 2] modification: add buzzer, bigger battery, more switches, minus HRM

@fanoush and @enaon, ha ha ha, I know. I will be careful. 😀
Thanks!

Nope! It didn't work. I guess I messed up something on the PCB somehow. Strange, I don't see anything wrong. hmmmm

Well, I disconnected the battery and reconnected, but it didn't solve the issue with the accelerometer. I think I have done all I could try. I don't want to damage other parts, so I will stop trying to figure it out. Although I'm going to miss the pedometer, but that's not a big deal.

My main reason to design the new case and adding so many (most people won't need it) buttons and buzzer and bigger battery was for my golfing (https://banglejs.com/apps/?id=golf-gps ). Currently it uses swipes for moving the holes and adding/subtracting scores while I'm playing, but if I touch (and slide) accidentally, the score or the hole changes unintentionally. That's why I wanted to have physical buttons (left/right and up/down) and bigger battery for continuous use of GPS. The buzzer is my preference over the vibration motor.

Although I lost the pedometer, I'm happy with the other modification. I have attached some pictures to show the internal arrangement of components in case someone's interested.

The motor is moved to the right side wall in a tightly fit hole. This motor vibrates radially, not axially, so it feels much stronger than original configuration (taped on the battery). The buzzer sounds loud enough. I have tested with a MOSFET and direct drive from the pin D43, but didn't see any difference, so just connected directly to the pin D43 for simplicity. As for the battery life, I tested yesterday with continuous GPS running after full charge and it lasted over 9 hours.

5 Attachments

That's awesome! Turning the motor on its side and fixing it to the case directly to amplify the buzz is something I could imagine to do in my next version as well since it is well cushioned/dampened when on the battery.

I opened my modified watch again to measure current for other reasons, and found the accelerometer was loose from the PCB. I gently touched it and was detached easily. During the modification, I haven’t touched that area with anything, especially the soldering iron.
Anyway, I’m trying to reattach it to see if I can get the accelerometer function again, but not successful yet.
But I noticed the number of pins on the package was different from the datasheet linked from the technical information page.
See attached screenshot of a part of the datasheet and a picture showing where the accelerometer used to be. In the datasheet, it’s 16 pins but the actual part has only 12 pins. Could anyone tell me what’s the actual part number? I want to see correct datasheet.

2 Attachments