FSR 402 force sensor: specs
Round thick-film force sensing resistor whose resistance falls as pressure on its 14.68 mm active area increases.
Specs
| Spec | Value | Source |
|---|---|---|
| Actuation force | About 0.2 N minimum | source Device Characteristics (p.2) |
| Force sensitivity range | About 0.2 N to 20 N | source Device Characteristics (p.2) |
| Non-actuated resistance | More than 10 Mohm | source Device Characteristics (p.2) |
| Force repeatability, single part | +/-2 % | source Device Characteristics (p.2) |
| Active area (Model 402) | 14.68 mm diameter | source Model 402 Sensor Mechanical Data (p.6) |
| Nominal thickness (Model 402) | 0.46 mm | source Model 402 Sensor Mechanical Data (p.6) |
| Operating temperature test points | -40 C cold and +85 C hot tested | source Device Characteristics (p.2) |
| Rise time | Under 3 microseconds | source Device Characteristics (p.2) |
Power
| Value | Source | |
|---|---|---|
| Supply | Resistive sensor, no supply pin; the sheet's divider example uses V+ of 5 V | source Application Information (p.3) |
Pinout
We don't publish a pin table for this part: no official source we could verify gives one. Check the labels printed on your module, and see the notes below.
Two-wire sensor; the sheet lists connector options (bare tail, female contacts, solder tabs) and no pin names. The listing's connector type is not stated.
Build with it
Project ideas for the FSR 402 force sensor. Each link opens Soldr with the prompt filled in; Soldr assigns the pins, checks power and shows how to wire every part.
- Press-strength meter: A divider with a fixed resistor feeds one analog input, as in the sheet's example circuit.
- Drum pad trigger: The sensor rise time is under 3 microseconds, so a code threshold catches quick taps.
- Pressure-controlled LED brightness: Run the divider from 3.3 V so the analog input stays within the board's range.
- Foot-press counter: Learning project; the sheet reports a tap durability test of 10 million actuations.
Common mistakes
- Reading it without a measuring resistor: wire it in a divider, VOUT = RM x V+ / (RM + RFSR), with RM chosen for the force range (source: link, Application Information).
- Swapping the divider order and expecting the same trend: with RM and RFSR swapped the output falls as force rises (source: link, Application Information).
- Treating it as a precise scale: the graph values are reference only and depend on the actuation mechanics (source: link, Application Information).
Not covered by the official source
- Model confirmed as FSR 402 (14.68 mm active area) from the 400-series sheet.
Sources
- link (Interlink Electronics FSR 400 Series data sheet, P/N 94-00027 Rev. D)