| ring | width | thickness | sizes | price |
|---|---|---|---|---|
| mine | 7.0-7.6 | 2.4 | 5.5-infinite | ~$50 |
| circular | 7.8 | 2.55 | 6-14 | $349 |
| oura | 7.9 | 2.88 | 4-15 | ($499 or $349) + $6/mo |
| galaxy ring | 7.0 | 2.6 | 5-13 | $399 |
| ultrahuman | 8.1 | 2.45-2.8 | unclear | $349 |
6.9mm width can be made by inserting electronics mid-print
- jlcpcb: $186.59 for 2 assembled
- board: $0.40
- components: $26.38
- SMT (per unit): $0.86
- inspection: $3.14
- everything else is fixed costs
- battery: $3.50
- casing: $0.08
total: $34.36
- bq27427: battery monitor
- max30102: spo2 + heart rate
- lsm6dsox: accelerometer + gyro; provides step counter + gesture detection
- tmp117: skin temperature sensor
- im72d128v01: mic, higher-quality than most smartphones
- 17 mah battery