Difference between revisions of "Rev200 mods"

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m (SCMC)
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* remove 1.25mm headers for EC30, replace with single 12x0.8mm header.  add 3.3V to 5V level shift output.
 
* remove 1.25mm headers for EC30, replace with single 12x0.8mm header.  add 3.3V to 5V level shift output.
 
* need to determine the accuracy of the RTC.  Seems to be drifting.
 
* need to determine the accuracy of the RTC.  Seems to be drifting.
 +
* R206, R216 -> 6.66k to scale range 0-5V to 0-3.0V
 +
* bridge current sense duplicate phase U,V sense
  
 
==IMU==
 
==IMU==
 
* probably want to upgrade dual axis IMU  
 
* probably want to upgrade dual axis IMU  
 
* battery measurement circuit needs to be re-done.
 
* battery measurement circuit needs to be re-done.

Revision as of 03:09, 16 September 2009


PCB needed Revisions

  • debug documentation should should show all TP pads, and not be the mirror image.

current sensors

  • presently 5V current sensor becomes 3.283V, but ADC reference is 3.0V so of the 75.76A range (0->5V), only 69.23A are viable. Thus range is -37.88A to +31.34A. The scale factor is 65536 / (5/.066 * 3/(5*10/15.23)) = 946.6789

FET

  • populate coin charger as default with 6.3V target voltage (R=1.21meg)
  • way to measure coin cell voltage without charger enabled? MTR ENABLED -> disable 6V LDO
  • change D13 to diode that actually has 200mV drop @ 1uA. BAS116-F-7 appears to have 427mV @ 0.3uA

SCMC

  • populate so local vbat is default (R222, R233 installed)
  • locate IMU header for easy access. possibly rot180 - or move 2mm away from edge.
  • remove 1.25mm headers for EC30, replace with single 12x0.8mm header. add 3.3V to 5V level shift output.
  • need to determine the accuracy of the RTC. Seems to be drifting.
  • R206, R216 -> 6.66k to scale range 0-5V to 0-3.0V
  • bridge current sense duplicate phase U,V sense

IMU

  • probably want to upgrade dual axis IMU
  • battery measurement circuit needs to be re-done.