Hi Jose,
You will first need to convert the RAW ADC values. You can use the following formula to do so calibratedData=(uncalibratedData-offset)*(((vRefP*1000)/gain)/4095); where offset = 0, vRefP=3, gain = 1; VSenseBatt = calibratedData *2; % as the voltage is divided, multiply it by two Finally in order to estimate the battery capacity, you can use the following table, which we've derived from the battery datasheet :- Remaining Capacity Voltage 0.0% 3.2 5.9% 3.627 9.8% 3.645 13.8% 3.663 17.7% 3.681 21.6% 3.699 25.6% 3.717 29.5% 3.7314 33.4% 3.735 37.4% 3.7386 41.3% 3.7566 45.2% 3.771 49.2% 3.789 53.1% 3.8034 57.0% 3.8106 61.0% 3.8394 64.9% 3.861 68.9% 3.8826 72.8% 3.9078 76.7% 3.933 80.7% 3.969 84.6% 4.0086 88.5% 4.041 92.5% 4.0734 96.4% 4.113 100.0% 4.167 I hope that helps, please do not hesitate to contact me if you have any further queries. Best regards, JC -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Jose F. Mingorance-Puga Sent: 26 February 2013 09:57 To: [email protected] Subject: [Shimmer-users] Monitoring battery levels Hello, I am trying to roughly monitor the battery levels of the shimmers, shimmer2r. I am reading the values of the analog channel 7 (AnEx7). A part from the crosstalk and other interferences that might be in, what are the common ranges of values expected after the AD converter? I am getting something between 2400 and 2700 out of the AD. What range should be considered as low charge, high charge? Sincerely, Jose F. Mingorance-Puga _______________________________________________ Shimmer-users mailing list [email protected] https://lists.eecs.harvard.edu/mailman/listinfo/shimmer-users
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