Test Fixtures & Bed-of-Nails

How to test a board quickly and repeatably. For a one-off, PCB Tools (PCBite, clips) is enough. For 50+ boards or production, you need a fixture: pogo pins on test points, edge clamps for connectors, a programming header, and a power feed. Pair with Debug Probes for in-fixture flashing, Multimeters and Power Supplies for measurement, and Instrument Software for running the test sequence. For designing testable boards see PCB / EDA Suites — DFT (design-for-test) starts in the schematic.

Flexible / one-off fixturing

• ★ PCBite (Sensepeek) — see PCB Tools. Magnetic flexible probes that "fixture" any board in 30 seconds. The default for prototype-tier "I need to probe 4 nets reliably while debugging."
• Sensepeek PCBite Pro — bigger / more probes for low-volume production tests.
• SMD test clips (Pomona / KZL / Hirschmann) — for IC pin-grabbing without designing test points.
• Edge clamps / Pomona test clips — short-run connector-edge fixturing.

Pogo-pin / bed-of-nails fixtures

• ★ DIY 3D-printed pogo-pin jigs — a 3D-printed top plate + spring-loaded pogo pins (P75-D2 / P75-E3 are the hobby standards from Mill-Max / Yokowo / generic) is the small-shop production-test workflow. Designs on Thingiverse / GitHub / Hackaday. Combine with an Arduino / Pi test controller.
• Mill-Max / Yokowo / Harwin pogo pins — premium spring-loaded probes for thousands-of-cycles fixtures.
• PCB-mount pogo headers (e.g., Tag-Connect TC2030) — solderless 6-pin or 10-pin programming/test footprints; insert pin = make contact. Required for almost every commercial product's debug header.
• GoldFinger / Verifies / Ingun — commercial bed-of-nails frame manufacturers; serious money.

Programming / "in-circuit programming" fixturing

• Tag-Connect TC2030-IDC / TC2050 — the canonical no-header solderless programming probe. Replaces a soldered SWD header on production boards. Pricier than a 6-pin, worth it.
• PicKit clips / ICSP headers — for AVR / PIC programming.
• Edge-fingers + spring connector — alternative to pogo pins for edge-card programming.

In-circuit test (ICT) and boundary-scan

• Boundary-scan / JTAG-chain test (IEEE 1149.1) — hooks every chip's IO into a serial scan chain so you can verify connections without physical probes. Toolchains: OpenOCD scan chain, TopJTAG, JTAG Live (XJTAG). The right answer for dense BGA boards where bed-of-nails is impossible.
• OpenBSP — FOSS boundary-scan tooling; niche but active.
• GenRad / Teradyne / Keysight ICT systems — the production-line equipment; six-figure money, outside hobby scope.

"Test the board" as code

• ★ Custom Python test harness — pyvisa (drives DMMs, PSUs, scopes), pyserial / pyOCD / probe-rs (drives the DUT), pytest for assertions. The standard small-shop test rig.
• TestStand (NI) — production test orchestration; closed, expensive, ubiquitous in factories. License-bound.
• OpenHTF (Google's open-source hardware test framework) — Apache-2; a real alternative for production test sequencing.
• HardwareTestRig / hwtest — community Python frameworks on GitHub for simple hobby fixture orchestration.

Connectors / cabling for fixtures

• IDC ribbon harnesses — for programming pin-outs to the DUT.
• DB-9 / DB-15 / DB-25 — old-school but still common for fixture I/O.
• D-sub interface modules with terminal blocks — clean way to break out fixture wiring.
• Banana → BNC → SMA cabling for routing instrument signals to fixture pins.
• Mating connectors / sockets for plugging the DUT into the fixture (Hirose DF40, JST SH/PH, Molex Picoblade are the small-board favorites).

License / pricing notes

• Fixture hardware is mostly mechanical — no license issues.
• TestStand is per-seat licensed and expensive; OpenHTF is FOSS and a real alternative for new projects.
• Tag-Connect is patented; clones exist on Aliexpress but the genuine connector is cheap enough that fighting it isn't worth it.
• For hobby use, PCBite + a pyvisa script covers most one-off and small-batch production needs without buying a "real" fixture.

Pick this if…

• Probing 1–10 boards, debugging: PCBite.
• Making 50–500 boards, no fixture yet: 3D-printed pogo-pin jig + Tag-Connect.
• Running production, hundreds per week: custom bed-of-nails + Python harness with pyvisa + probe-rs.
• Programming production boards without a soldered header: Tag-Connect TC2030.
• Dense BGA board, no physical access: boundary-scan / JTAG-chain test.
• Big shop, NI-shop: TestStand.
• Big shop, FOSS-shop: OpenHTF.