DFR0996
Jose.Garcia3512 2026-07-31 01:17:10 71 Views1 Replies Need to know if the VCC can be paired with the INA or INB to set or reset. Perhaps a longer pulse would work.
Quick thing about the pin naming first: INA (Pin A) = SET (relay ON), INB (Pin B) = RESET (relay OFF). They're not both toggle pins.
Yes, pulling INA or INB HIGH to VCC (with GND on the - pin) triggers the action, same as the Arduino example does. It needs to be a pulse, not a constant HIGH:
min 2ms per the specs, >4ms for reliable switching
10–50ms is a safe practical window
don't hold HIGH for more than 1 minute (coil damage risk)
Longer pulse works fine. The on-board driver chip internally handles the ≥100ms that the bare HF3F-L relay coil needs.
Start with "Working Principle and Supplementary Instructions" for the exact pulse constraints: https://wiki.dfrobot.com/dfr0996/docs/17987
Jason.Miao 