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ANT+ / MCU project

I want something on my handlebars which tells me when my heart / cadence / power ANT+ readings are in a specified band (or higher or lower).

Like this:

But not retarded, expensive, or driven by a smartphone.

It doesn't need to be configurable on the fly - I'm perfectly happy to do that over serial or something.

But it does need to know the sensor ID for each set of LEDs and the range of the band.

ie "cadence, sensor ID: 97827, range: 85-105"

Then if my cadence is between 85-105, the middle green LED comes on. Lower, left hand LED (yellow?) comes on. Higher, right hand LED (red?) comes on. Bonus points for having overlaps where two LEDs are on for higher resolution.

If there's no readings, no LEDs come on. Also should pick them up without prompting when powered on (ie when I forget to connect my heart strap until halfway down the road...)

Needs to be waterproof (obv) and the LEDs visible during the day. Ideally powered by a CR2032 but anything easily bought and recharged would work as long as it doesn't change the size too much.

Must fit on handlebars or stem or top tube. Probably no more than 20mm x 60mm x 20mm.

Triple bonus points for having the LEDs for each sensor instantly distinguishable.

Battery life has to be at least 30 hours (for long rides).

Power control by a mechanical switch is fine but power-saving sleep is bonus points.

Ideally battery should last a year of normal use (~30-60 minutes a day).

What have I forgotten?

  • Slight change of spec: that Ti chip does Bluetooth. Being able to configure the numbers over that would be perfect

Even if it's "switch into Bluetooth mode, configure, switch back to ANT+, ride" RJ

  • 09:39

[RJ Partington] V2 needs two threshold bands for high-low interval work. And a pony. And gold sparkles. RJ

  • 10:30

[RJ Partington] might be helpful for understanding the UART flow RJ

  • 21:19

[RJ Partington] and more than you ever wanted to know about ANT+ and power meters (that wiki page needs to be editable) although that slowtwitch isn't the page I thought but still interesting


Reference Design