category: hardware

IoT Temperature and Humidity Sensor

25 Jan, 2019 - 7 minutes

This is a walkthrough for setting up a NodeMCU with a Si7021 temperature and humidity sensor as an IOT device.

It will collect sensor information, and continuosly report them to Grafana and MQTT.

Reading SDRAM configuration data with the Bus Pirate

SDRAM DIMMs have a standardized way of storing configuration data in an on-chip EEPROM. In this case the EEPROM is a 24C02, 256 Byte one. The storage of information in it is defined by the Serial Presence Detect - SPD standard. It integrates into the SMBus when plugged into a computer, and the BIOS uses the data contained to initialize memory access.