SEN0322 — i2c address & wiring
Factory-calibrated electrochemical oxygen sensor, 0–25 %Vol, plug-and-play over i2c.
Key facts
SEN0322 at a glance
| i2c address | 0x700x710x720x73 address-selectable via pins/jumpers |
|---|---|
| Logic voltage | 3.3–5 V |
| Type | sensor |
| Part | DFRobot SEN0322 |
| Ships with | Gravity |
| Datasheet | DFRobot SEN0322 — manufacturer documentation ↗ |
The chip
What the DFRobot SEN0322 actually is
Gravity-ecosystem electrochemical O2 module reading absolute oxygen concentration from 0 to 25 %Vol, factory-calibrated with onboard processing — the host just reads a percentage over i2c. Address pads select four addresses, 0x70 by default.
Watch out: Electrochemical cells are consumables: the sensing element depletes over roughly two years and drifts as it ages, so plan on recalibration or replacement. Its 0x70-range addresses also sit right on top of TCA954x multiplexers and HT16K33 backpacks — strap accordingly.
Wiring
How to connect the SEN0322
The SEN0322 talks i2c at address 0x70 (up to 4 selectable addresses, handy when you need more than one on the same bus). It runs at 3.3–5 V, so match your host's logic level — if your host is 5 V and a board on the bus is 3.3 V-only, add a level shifter. Use the compatibility checker to confirm the exact cable for your setup.
Because the address is selectable, you can run several SEN0322 boards on one bus by setting each to a different address — no extra wiring beyond the shared SDA/SCL.
Wiring is the usual four: power, ground, SDA and SCL, plus pull-up resistors — almost always already fitted on the breakout. Nothing showing up? Run an i2c scan first; if the bus is silent, the 7-step checklist finds it faster than guessing.
Ecosystems
Plug-together options for the SEN0322
SEN0322 breakouts ship with Gravity — keyed 4-pin cables carrying power, ground, SDA and SCL, so there's nothing to solder and nothing to wire backwards. Chain it to the next board and keep going.
Running a mixed bench? Those ecosystems interoperate more than their marketing suggests — see every connector pairing for the cable or adapter you need, or the standards overview for how they compare.
Alternatives
Other air quality boards
Watch the bus
Boards that clash with the SEN0322
These want addresses the SEN0322 also answers (0x70, 0x71, 0x72, 0x73), so they can't share a bus with it untouched. If one is address-selectable, strap it elsewhere; if not, the conflict guide covers the multiplexer and second-bus routes, and the collision roundup explains why a scan won't warn you.
Get one
Questions
SEN0322 i2c FAQ
What is the SEN0322's i2c address?
The SEN0322 uses 0x70 or 0x71 or 0x72 or 0x73, selected with an address pin or solder jumper on the board. If a scan turns up something unexpected, our i2c address list names the usual suspect for every address.
What voltage does the SEN0322 run at?
3.3–5 V logic. That range covers both 3.3 V and 5 V hosts, so it drops onto a Pi, ESP32 or Arduino without a level shifter.
Can I use two SEN0322s on one i2c bus?
Yes — set each one to a different address (0x70, 0x71, 0x72, 0x73) using its address pin or jumper, then wire both to the same SDA/SCL. That gives you up to 4 on a single bus before you need a multiplexer.
Does the SEN0322 work with Gravity?
Yes — SEN0322 breakouts ship with Gravity, so it plugs straight in with no soldering. Mixing ecosystems? The compatibility checker gives you the exact cable or adapter.
What should I watch out for with the SEN0322?
Electrochemical cells are consumables: the sensing element depletes over roughly two years and drifts as it ages, so plan on recalibration or replacement. Its 0x70-range addresses also sit right on top of TCA954x multiplexers and HT16K33 backpacks — strap accordingly.