Bangle .js app developer

[espruino-discuss]

Posted at 2020-05-04 by herman_arenas

Hi guys. i want to read a analog voltage from 0-3.3 volts analog signal generated from an antena, filter the reading with a software bandpass filter, and normalize it into a selectable moving average and display a gauge in the screen with vibration and beeps after a selectable tresshold is passed, measurement time should be selectable but in the ms range.
I want to hire someone who can develop the software part of this, if anyone is up to it please let me know.

[gfwilliams]

Posted at 2020-05-05 by @gfwilliams

I'll just move this into the 'work' section (which is the area we've got for requests like this).

Just so that we know what's involved, how would this analog signal come into the Bangle? Would you use another bluetooth device and get the data from that?

[espruino-discuss]

Posted at 2020-05-05 by herman_arenas

Just so that we know what's involved, how would this analog signal come into the Bangle? I was thinking in the "speaker" port that was left avaliable, could i change this digital output to an analog input? or maybe tweaking the hardware a little and get to an avalible port in the nordic.
The signal is really simple a capacitor one end connected to 3.3v and the other to the analog input.
Would you use another bluetooth device and get the data from that? Nope, the device is still the same just need to get the analog signal into the watch directly.

[gfwilliams]

Posted at 2020-05-06 by @gfwilliams

Sadly the speaker port is output-only, and digital at that.

However if you were willing to do a little more poking you could unsolder a few components from the heart rate PCB (easily accessible on top) and then there's an available analog input on that.

It's not something I'd advise doing for anything in production, but for a prototype or something it'd be pretty straightforward.

[espruino-discuss]

Posted at 2020-05-06 by herman_arenas

Great, i see that the HRM is the U2 noted in the pic is there a pin map on the IO expander or which oin should i get for the signal to go directly to D29 HRM Analog pin.
Im i correct?
Many thanks for the help.

Attachments:

• WhatsApp Image 2020-05-06 at 12.04.46 PM.jpeg

[gfwilliams]

Posted at 2020-05-07 by @gfwilliams

This should help. Basically if you remove all the components covered by the red boxes, you should be able to get at the IO pins (in the red boxes) pretty easily.

Attachments:

• HRM-pic.png