ADS1015-Q1: Continuous conversion mode or Single shot mode

Shinji-san,

I generally recommend using the ADS1015 in single-shot conversion mode. When you start the conversion, you wait for the conversion to complete and then read the data. The amount of time is dependent on the data rate setting. The time needed would be [1/(data rate)]*1.1+20us. There is an added 10% for the variation of the internal oscillator for the device.

For example, if the data rate is 1600SPS, then you would start the conversion and wait:

(1/1600)*1.1 + 20us = 625us*1.1 + 20us = 708us

Then you would read the data.

You can change the input channel with the MUX[2:0] bits of the config register at any time. However, when you program the config register, the ADS1015 does not make the change immediately. It completes any conversion in progress and then makes the change to the config register.

If you are using continuous conversion mode, this may cause problems in reading back data because if you make a change, you may need to wait up to 2 data periods to get the data from the new config register settings.

You could use continuous conversion mode, but I always find it easier to use single-shot conversion mode and wait a set period to read the data.

Joseph Wu