Dear Jong,
Thank you for the information.
I do believe there is a big cross talk between the accelerometer
(probably for axis Z) and the battery readings. Did you ever experience
this issue? How to address it? I was trying to subtract a scaled value
of the axis Z to the battery readings but seems to not to work, i.e.
cannot model this cross talk as linear. Any ideas on it?
Sincerely,
Jose F. Mingorance-Puga
On 27/02/2013 9:03, Jong Chern Lim wrote:
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
_______________________________________________
Shimmer-users mailing list
[email protected]
https://lists.eecs.harvard.edu/mailman/listinfo/shimmer-users
