Force, the seat node.
Seat-by-seat rowing force measurement: one node on each seat’s rigger backstay. It records the force curve of every stroke, shows the rower their own peak and curve live, and saves the session for you to download at the dock.
What the rower will see on the water.
Their own peak and their own curve, on a 3.5″ screen, with three keys down its edge.
It brings its own network to the dock.
- Its own Wi-Fi network
- Each node runs its own network. Join it from a phone, open a browser, and the node’s page is there. There’s no app to install.
- Calibration, and where it stands
- The firmware calibrates against up to 5 known weights and reports its own worst-case error. We haven’t calibrated a node yet, so for now force reads in raw sensor units. The timing measures don’t need calibration.
Specifications.
- Load cell
- 50 kg, in series on the rigger backstay
- Fits
- Vespoli riggers for now; more are coming soon
- Electronics
- Adafruit Feather ESP32-S3 and an HX711 breakout on a RowTech carrier board, sampling at 80 Hz
- Catch timing
- Placed on the node to within about 3 ms, interpolated between samples 12.5 ms apart
- Calibration
- Up to 5 points against known weights; reports its own worst-case error; not yet run on a node
- Doesn’t measure
- Oar angle, or force in calibrated units yet; it sits on the backstay rather than the oarlock to keep the cost down
- Screen
- 3.5″, 480×320 TFT
- Keys
- VIEW, TARE, POWER
- Seat number
- Set on the node’s own web page
- Network
- Its own Wi-Fi network; download from a phone or laptop
- Storage
- microSD, with strokes.csv, curves.bin, events.csv and meta.json for each session
- Battery
- 3000 mAh
- Target price
- $399 per seat
The case is a concept design.