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.
- 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
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 termanl 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.