Warnings

In addition to the Lo-tech.co.uk Terms and Conditions, the following warnings should be observed when building and using lo-tech.co.uk products and designs:

• Lo-tech products and designs are not fault tolerant and are not designed, manufactured, or intended for use in control equipment in hazardous environments requiring fail-safe performance, such as industrial machinery, in which the failure of such components could lead to death or personal injury.
• Do not expose to water, moisture or extremes of temperature (below -40°C or above 85°C).
• Take care whilst handling to avoid mechanical and electrical damage to the device and connectors.
• Take suitable precautions to minimise risk of causing damage by electrostatic discharge.
• Connection to unapproved devices may affect compliance or result in damage and invalidate any warranty.
• Connections to should be made only be made with the power supply disconnected.
• ESD handling precautions should be observed when handling electronic components.

Product Specific Additional Warnings

Lo-tech GPIO Interface for Raspberry Pi

The following warnings apply to all versions of the board:

• The board must be mounted to the Raspberry Pi using screws and 11mm spacers. Failure to observe this may result in a short-circuit causing permanent damage to both components and the attached power supply.
• Ensure that any circuits attached to GPIO Interface are powered by a suitably rated power supply that complies with the relevant regulations and standards applicable to the country of intended use.
• Resistor network values must be calculated based on the attached equipment. Failure to select correct values can result in permanent damage to the GPIO Interface, the Raspberry Pi, attached equipment, or all of the above.

The following additional warnings apply to the Lo-tech GPIO Interface Board:

• The GPIO Interface board inputs and outputs are designed for low-frequency switching operation, for example for attachment to human-operated switches and controls.
• The maximum voltage applied to opto-isolated inputs, both across each terminal pair and relative to the Raspberry Pi power supply ground, is 16V.

The following additional warnings apply to the Lo-tech GPIO Interface Board rev.2:

• The GPIO Interface board opto-isolated inputs and Darlington outputs are designed for low-frequency switching operation, for example for attachment to human-operated switches and controls.
• The 1-wire bus output is designed for short line length operation, typically under 5m.
• Incorrect setting at JP1 can result in permanent damage to the GPIO Interface, the Raspberry Pi, attached circuits, and the attached power supply (or supplies).
• The opto-isolated inputs:
  • have a maximum voltage, both across each terminal pair and relative to the Raspberry Pi power supply ground, of 30V
  • do not provide transient over-voltage protection beyond the design maximum of 30V
• The Darlington outputs:
  • have a maximum voltage between COM terminal and the Raspberry Pi power supply ground of 30V
  • support the direct connection of inductive loads when COM terminal is connected to the load supply rail, however the voltage capacity should be de-rated such that the maximum observed voltage remains within the 30V specification under flyback conditions.

Lo-tech PDT Rollertec Interface

The following warnings apply to all versions of the PCB set:

• The Lo-tech PDT Rollertec Interface is designed to enable a RaspberryPi to operate and monitor the status of a PDT Rollertec garage door controller for the purpose of home automation, for example to provide voice control via Apple HomeKit. The kit provides no additional safety or security features to the PDT Rollertec garage door controller, and it is therefore essential that the attached garage door is operated in accordance with the manufacturers instructions, save for the method of issuing door control commands 'open' and 'close'. MOVING DOORS CAN CAUSE SERIOUS INJURY. NEVER OPERATE THE DOOR UNLESS YOU CAN SEE IT. THE USER OF THE DOOR REMAINS AT ALL TIMES FULLY RESPONSIBLE FOR ITS SAFETY.
• Not all doors are fitted with edge impact detectors, and even where fitted these should not be relied upon. A PHYSICAL STOP BUTTON SHOULD ALWAYS BE PROVIDED WITH THE INSTALLATION.
• The Lo-tech PDT Rollertec Interface must be mounted to a Raspberry Pi using screws and 11mm spacers. Failure to observe this may result in a short-circuit causing permanent damage to both components and the attached power supply.
• Use of this kit requires wiring to the Rollertec PCB, which has exposed 230V mains terminals. Ensure the board is fully isolated before opening the enclosure or making connections. If in any doubt, contact a qualified electrician.
• The kit has been tested with PDT Rollertec v5 only and is considered a component. The end-user is responsible for system integration, testing, and validation of the specific garage door controller in use to determine compatibility. Inputs (Close, Com, Open) and outputs (T13, T14, T15) are designed to integrate with 5V TTL level signals.
• Radio frequency (RHI) performance of the RaspberryPi and attached peripherals is highly dependent on the power supply quality. The use of an official RaspberryPi branded power supply is recommended.
• When powering RaspberryPi through the Lo-tech PDT Rollertec Interface (RaspberryPi model B and 2B only), connect either 5V or 8-24V supply where indicated. NEVER CONNECT BOTH SUPPLIES SIMULTANEOUSLY. DO NOT CONNECT A POWER SUPPLY TO THE RASPBERRYPI ITSELF IN THIS CONFIGURATION.
• Associated software (Homebridge and associated plug-ins) may not be error-free.

See Also

• Terms and Conditions
• Compliance