Buy BMT HC-SR04 Ultrasonic Sensor Online in South Africa - Stock & Specs

Key specifications to check

• Operating voltage: typically 5V (confirm module markings if you plan to use 3.3V systems).
• Sensing range: commonly 2 cm to 400 cm (specify effective range in product listing).
• Accuracy and resolution: often quoted around 3 mm, varies with surface and angle.
• Trigger/Echo interface: Trigger input (pulse >10 s), Echo output pulse width proportional to distance.
• Beam pattern: conical beam - object size and angle affect returns.

Spec comparison (typical HC-SR04 vs similar modules)

Price note: units are commonly available online in South Africa. Typical retail ranges can be ZAR 30 - ZAR 120 per module depending on seller, packaging, and whether headers or cables are included. These figures are estimates and will vary by supplier and stock levels.

Compatibility and wiring

The HC-SR04 uses a simple four-pin layout: VCC, Trig, Echo, GND. Typical wiring to a 5V Arduino-style board is straightforward: VCC to 5V, GND to ground, Trig to a digital output, Echo to a digital input. When connecting to 3.3V logic (Raspberry Pi, ESP32), use a 1k-2k resistor divider or a logic-level converter on the Echo line to avoid over-voltage on the MCU input.

Distance calculation and timing

Measure the Echo pulse width and apply the conversion: distance (cm) = (Echo pulse width in microseconds) / 58. Example: a 1000 s pulse corresponds to about 17.2 cm. For reliability allow for environmental factors such as temperature and surface reflectivity.

Trigger: send a 10 s HIGH pulse
Echo: measure HIGH pulse width (s)
Distance (cm) = pulseWidth / 58

Practical examples for South African projects

• Student robotics: use HC-SR04 for simple obstacle avoidance in line-following platforms; pair with motor drivers and a microcontroller.
• Water tank level sensing (low-cost): mount above surface; note foam and turbulence can affect readings; average multiple samples to stabilise output.
• Workshop automation: detect presence of parts on conveyors; verify minimum object size and reflectivity for reliable detection.

What to check before purchasing online

• Stock & lead times: confirm branch availability or shipping estimates; some sellers list Samrand or Cape Town collection options.
• Included accessories: headers, jumpers, or mounting brackets save time during assembly.
• Seller specs: check measured range, supply voltage, and whether the Echo output is 5V (important for 3.3V systems).
• Bulk & education purchases: request a VAT invoice or a quote for class/department procurement.

Bundles and accessory suggestions

• Header pins and dupont cables for breadboarding.
• Logic-level shifter or resistor divider for 3.3V microcontrollers.
• Mounting brackets or 3D-printed holders (3D printing filaments available locally).

Availability and support at Communica

Check Communica's sensor and prototyping categories to see current stock and branch pickup options. For educational or larger orders, request a quote and VAT invoice via the account services on the site. If you need to compare specs, use product listings and datasheets to confirm voltage and echo behaviour before adding to your cart.

Sources

• Communica - Collections and product categories
• Arduino: HC-SR04 (Ping) tutorial and timing details
• SparkFun: Ultrasonic distance sensors guide and practical tips
• Ultrasonic sensor - Wikipedia overview and principles