Hi All,
Inside the code, the ADC is said to take pressure sensor data in and send it to portH pin 7 via serial port 2 in SPI. But the datasheet for the BMP085 says it has an internal ADC (it also says it is an I2C device--does this mean the ADS7844 ADC utilizes I2C for the accel, gyro, and baro? I admittedly do not know much about I2C...).
I am wondering how the ADC can take in a digital signal, does it take in a digital signal? I have attached the datasheet I found for the BMP085.
Thank you!
Replies
I2C is a "two wire" serial protocol that uses a clock to synchronize data transfer. The clock line is SCL the data line is SDA. It's a clever protocol in that many devices can share the same two wires yet easily detect collisions. There's one master and many slave devices. Each slave has a unique address so the master can directly communicate with a particular device.
The BMP085 datasheet says it's an I2C device with onboard ADC so whatever is interfacing with the sensor is using I2C; no other choice. The ADS7844 is a multi-channel ADC that uses SPI, a 4-wire protocol. Similar to I2C it uses a clock signal SCK, or in the datasheet, DCLK, as well as a chip select !CS, and two wires for data, a Master In Slave Out (MISO) or DOUT in the datasheet, and a Master Out Slave In (MOSI) or DIN in the datasheet. It doesn't have any means of taking in a digital signal.
What IMU and what code are we talking about? Can you quote the lines in the code, maybe?
Probably someone else will come along with a specific answer. All I'm good for is general knowledge at this point :D