Extension module for Nettemp and Raspberry Pi

Description

The Nettemp system is used to monitor the temperature measurement and other parameters, display results in the form of statistics on the server's website built on Raspberry Pi or other platform based on the Linux system, and control. It has a user interface that allows easy configuration of sensors, setting parameters and tracking measurements.

Software (open source) is available on GitHub (Nettemp GitHub), while the project website is http://techfreak.pl/nettemp/ .

The extension module is compatible with Raspberry PI versions B and B +.

The expansion module has an I2C / 1-Wire converter (DS2482) through which DS18B20 temperature sensors can be connected using two or three wires. The converter supports a maximum of 8 sensors. Temperature sensors can also be connected to the GPIO4 line connector. In addition, I2C, UART and SPI interfaces have been derived. The module has 2 relays controlled by GPIO. Due to the platform operating voltage level of 3.3 V, logic level converters (TXB0102 and BSS138 transistors) have been built in, so that additional circuits operating at +5V can be connected to portions of I2C and UART connectors (Important: Connectors supporting voltage +5 V have been appropriately marked in the manual, not all connectors support voltage + 5V). You can connect, for example, a module with LCD (controlled by I2C), DHT11, DHT22, HTU21D, TSL2561 or pressure lighting to the derived interfaces. You can connect the radio module nRF24L01 to the SPI connector. The 1-Wire bus allows you to connect multiple sensors to one line, which means that there is no need to connect wires to each sensor separately. The module has a built-in voltage regulator +5 V and a DC connector, enabling additional voltage supply with a max. +12 V, this may require the installation of a small heat sink for the voltage stabilizer. In addition, a polymer fuse with a value of 750 mA has been built into the DC connector (it is resettable, thanks to which, it is enough to disconnect the power supply so that it functions properly again).

Details of the extension module:

• Derived 1-Wire interface (GPIO4 line),
• Derived 1-Wire interface from the built-in I2C / 1-Wire converter
• 2 relays with LED signaling,
• UART connector,
• 3 I2C interface connectors, eg for connection of pressure, lighting and LCD sensors,
• Connector with SPI interface, e.g. for radio module with nRF24L01 system,
• The output of a free GPIO24 pin, eg: for connecting the buzzer,
• Built-in voltage converter +3.3 V / 5 V for selected I2C and UART connectors,
• Compatible with Raspberry Pi versions B and B +

properties

• Integrated circuit: DS2482, TXB0102, LM1117-5.0
• Protection: 750 mA polymer fuse for DC input
• Input connector: Raspberry Pi connector
• Outputs / output connector: I2C, SPI, UART, 1-Wire
• Raspberry Pi power supply, additional power supply: DC connector from +7 to +12 V
• LED signaling: yes
• Dimensions: 64 mm x 58 mm
• Configuration: Vref for 1-Wire, VCC for UART
• Additional information:
  • built-in stabilizer +5 V
  • selection of reference voltage for 1-Wire sensors (VCC or GND)
  • possibility of connecting the radio module nRF24L01
  • for safety reasons, we recommend connecting a max. voltage to the relays. +12 V
• RoHS: yes

Included

• Assembled MOD-29.Z Expansion module for Raspberry Pi and Nettemp - "Temperature monitoring system and more"
• Temperature sensor DS18B20
• A set of connectors for self-assembly and 2 relays, are mounted: connector for Raspberry Pi, DC connector

To download

• User's manual