MM DS3231, BMP180 and I2C

Author	Message
TassyJim Guru Joined: 07/08/2011 Location: Australia Posts: 6624	Posted: 06:09pm 23 Nov 2016         Quote   - I have a future project where I want to measure two sets of pressures, one at atmospheric and a second at less than this (well within the BMP180's range) - can I address two BMP180's via I2C? (how)? The BMP085 has a XCLR pin that can be used a s chip select to allow more than one BMP085 on the bus. The BMP180 doesn't have that option.   Quote   - how does one know that the BMP180 address is &H77? (TassieJim's code to read BMP180 temperature and pressure) - how does one know that the RTC address is &H68? (Geoffg's code for SuperClock) Read the data sheets. They are readily available and should be studied if you want to get the most out of the devices without too much head-banging. Sometimes, you will need help but when you have the answers and the datasheets to compare them with, you will learn how to decipher the next datasheet. Sometimes (often) when you get a module it has a 3.3V regulator on board allowing 3.3 or 5V supplies to be used. The datasheets will tell you what the chip voltage is likely to be. If your RTC module has a regulator, both devices will be running the I2C at 3.3V The micromite I2C runs at 3.3V although I think all devices are 5V tolerant. The method you use to keep time and program flow will depend on the whole program requirements so there is no best way. Jim VK7JH MMedit