Difference between revisions of "Rev200 mods"

From DIDEAS Wiki
Jump to: navigation, search
m
m
Line 6: Line 6:
  
 
=PCB needed Revisions=
 
=PCB needed Revisions=
 +
==discussion==
 +
 +
* overall our goal is it keep to a minimum the number of changes.  The changes they we have proposed are absolutely necessary from our point of view.
 +
 +
* changing 0.8mm headers to 1mm
 +
** Obviously we would like to avoid this.  In particular have had cables made for the EC30-MILE and IMU.  However, with the other connectors I don't see a problem with this.
 +
 +
*4 Channel DAC
 +
** Have not made us of the DAC, however that very well could change as we will soon be doing automated testing.  Unless there is a very compelling reason to remove it - I suggest that it remain.
 +
 +
*Primary Li cells
 +
** Again, unless there is a compelling reason, I believe it should remain.  My understanding is that the foot print of the 2ndary and primary cells overlapped.  Although I guess there is a possible problem with through hole mounting?
 +
 +
* The present design with the current sensors can actually cause an over-voltage condition on the dsPIC.  When this happens there are offset and cross coupling issues on all channels.  The slight lose in resolution is minor compared with the upside.
 +
 +
* Hall sensor should remain.  The location of the sensor may change slightly. 
 +
** The purpose of the connection to TP252 is so that we may experiment with alternative sensors.  At present we don't have any.
 +
 +
 +
  
 
==FET==
 
==FET==
−
* w/clamp circuit - use thermal vias for R4 - this device is impossible to replace
+
* (1) w/clamp circuit - use thermal vias for R4 - this device is impossible to replace
 
** will try low temp solder and send to MPD  
 
** will try low temp solder and send to MPD  
  
−
* height of coin cells is too great.  need the original coin cell spec
+
* (2) height of coin cells is too great.  need the cells from this original coin cell specification
−
* pg 4/8 : populate coin cell charger as default  
+
* (3) pg 4/8 : populate coin cell charger as default  
 
** populate BT2,BT3 as default, DNP BT1,BT4 (but keep R18, D21)
 
** populate BT2,BT3 as default, DNP BT1,BT4 (but keep R18, D21)
 
** DNP D13 only if primary coins are installed.
 
** DNP D13 only if primary coins are installed.
Line 20: Line 40:
 
*** expect a 150-200mV drop across D13
 
*** expect a 150-200mV drop across D13
  
−
* change D13 (and D21 ?) to diode that actually has 200mV drop @ 1uA.  BAS116-F-7 appears to have 427mV @ 0.3uA
+
*(4) change D13 (and D21 ?) to diode that actually has 200mV drop @ 1uA.  BAS116-F-7 appears to have 427mV @ 0.3uA
 
** See : [http://www.diodes.com/datasheets/ds30233.pdf (PDF)] - Diodes Inc BAS116-7-F fig 3, pg 2]
 
** See : [http://www.diodes.com/datasheets/ds30233.pdf (PDF)] - Diodes Inc BAS116-7-F fig 3, pg 2]
  
  
−
* pg 4/8 : ability to measure coin cell voltage without charger enabled?  Connect pin 3 of U10 to something like the SFTYSNS_EN, or MTR_EN signal at TP97 or U20B
+
*(5) pg 4/8 : ability to measure coin cell voltage without charger enabled?  Connect pin 3 of U10 to something like the SFTYSNS_EN, or MTR_EN signal at TP97 or U20B
  
 
==SCMC==
 
==SCMC==
−
* pg 7/18 : change cutoff freq to ~15Khz for temp circuit (U22) R102=1k, C73=0.01u  
+
*(6) pg 7/18 : change cutoff freq to ~15Khz for temp circuit (U22) R102=1k, C73=0.01u  
  
−
* pg 7/18 : remove R232 - 10k for batt_temp_mon pullup
+
*(7) pg 7/18 : remove R232 - 10k for batt_temp_mon pullup
−
* pg 7/18 : remove R245 - 220 ohm for mtr_temp_mon pullup
+
*(8) pg 7/18 : remove R245 - 220 ohm for mtr_temp_mon pullup
  
−
* pg 7/18 : R206, R216 -> 6.66k to scale range 0-5V to 0-3.0V  (current sensors)
+
*(10) pg 7/18 : R206, R216 -> 6.66k to scale range 0-5V to 0-3.0V  (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
 
** 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
  
−
* pg 7/18 : bridge current sensor use same values phase U,V  
+
*(11) pg 7/18 : bridge current sensor use same values phase U,V  
  
  
−
* Pg 8/18 : increase size of resisters (by 10x) for supply voltage measurement (R91, R94, R221, R88).  Keep cut off freq the same.   
+
*(12) Pg 8/18 : increase size of resisters (by 10x) for supply voltage measurement (R91, R94, R221, R88).  Keep cut off freq the same.   
  
−
* pg 8/18 : populate so measurement of supply voltage is default (R222, R233 installed).  its easier to remove components than to add them.
+
*(13) pg 8/18 : populate so measurement of supply voltage is default (R222, R233 installed).  its easier to remove components than to add them.
  
  
−
* pg 3/18 : replace 1.25mm header for EC30 enc/hall w/ 12x0.8mm header
+
*(14) pg 3/18 : replace 1.25mm header for EC30 enc/hall w/ 12x0.8mm header
 
** [[http://mediawiki.dideas.com/index.php?title=Upd_2x0_218_controller#pinout  12x8 pinout]]
 
** [[http://mediawiki.dideas.com/index.php?title=Upd_2x0_218_controller#pinout  12x8 pinout]]
 
** [http://dhcp-17-197.media.mit.edu/ankle/for_mpd/prelim-EMILE3_070709.pdf  interface cable]
 
** [http://dhcp-17-197.media.mit.edu/ankle/for_mpd/prelim-EMILE3_070709.pdf  interface cable]
  
−
* pg 6/18 : replace HALL_C input with SSI_CLK 5V output  
+
*(15) pg 6/18 : replace HALL_C input with SSI_CLK 5V output  
  
−
* pg 11/18 : (CB) need to determine the accuracy of the RTC.  Seems to be drifting.
+
*(16) pg 11/18 : (CB) need to determine the accuracy of the RTC.  Seems to be drifting.
  
−
* pg 18/18 : Remove LSSGA before TP56
+
*(17) pg 18/18 : Remove LSSGA before TP56
  
−
* Connect TP56 to LSSGA connector. needs to protect dsPIC, but no other circuity.
+
*(18) Connect TP56 to LSSGA connector. needs to protect dsPIC, but no other circuity.
 
** adjust C95 for 15khz cutoff freq
 
** adjust C95 for 15khz cutoff freq
−
* pg 14/18 : Connect TP252 to LSSGA connector.  Needs to protect dsPIC, but no other circuity.
+
*(19) pg 14/18 : Connect TP252 to LSSGA connector.  Needs to protect dsPIC, but no other circuity.
  
  
−
* 3/18 : LSSGA connector  signals:
+
*(20) 3/18 : LSSGA connector  signals:
 
** AGND
 
** AGND
−
** A3V ref
+
** A3V ref (analog 3.0V reference) 
−
** A 3V supply
+
** A 3V supply ???? 
 +
*** Think I mean a 3.3V supply that can supply working current.  The reference can't (shouldn't) supply power for components.
 
** TP56 analog in
 
** TP56 analog in
 
** TP252 analog in
 
** TP252 analog in

Revision as of 21:55, 4 October 2009


PCB needed Revisions

discussion

  • overall our goal is it keep to a minimum the number of changes. The changes they we have proposed are absolutely necessary from our point of view.
  • changing 0.8mm headers to 1mm
    • Obviously we would like to avoid this. In particular have had cables made for the EC30-MILE and IMU. However, with the other connectors I don't see a problem with this.
  • 4 Channel DAC
    • Have not made us of the DAC, however that very well could change as we will soon be doing automated testing. Unless there is a very compelling reason to remove it - I suggest that it remain.
  • Primary Li cells
    • Again, unless there is a compelling reason, I believe it should remain. My understanding is that the foot print of the 2ndary and primary cells overlapped. Although I guess there is a possible problem with through hole mounting?
  • The present design with the current sensors can actually cause an over-voltage condition on the dsPIC. When this happens there are offset and cross coupling issues on all channels. The slight lose in resolution is minor compared with the upside.
  • Hall sensor should remain. The location of the sensor may change slightly.
    • The purpose of the connection to TP252 is so that we may experiment with alternative sensors. At present we don't have any.



FET

  • (1) w/clamp circuit - use thermal vias for R4 - this device is impossible to replace
    • will try low temp solder and send to MPD
  • (2) height of coin cells is too great. need the cells from this original coin cell specification
  • (3) pg 4/8 : populate coin cell charger as default
    • populate BT2,BT3 as default, DNP BT1,BT4 (but keep R18, D21)
    • DNP D13 only if primary coins are installed.
    • Would like the coin cells to have 6.0 to 6.1V to be fully changed. ABS maximum is 6.2V
      • It doesn't appear to be possible to obtain this tight voltage specification with 1% resistors and the (PDF) MIC5235 LDO. The LDO has up to 2% variation in its output over temperate. Thus a total variation of upto +- 3.65% could be expected.
      • 6.2 +- 3.65% = 5.98V to 6.42V
      • expect a 150-200mV drop across D13
  • (4) change D13 (and D21 ?) to diode that actually has 200mV drop @ 1uA. BAS116-F-7 appears to have 427mV @ 0.3uA
    • See : (PDF) - Diodes Inc BAS116-7-F fig 3, pg 2]


  • (5) pg 4/8 : ability to measure coin cell voltage without charger enabled? Connect pin 3 of U10 to something like the SFTYSNS_EN, or MTR_EN signal at TP97 or U20B

SCMC

  • (6) pg 7/18 : change cutoff freq to ~15Khz for temp circuit (U22) R102=1k, C73=0.01u
  • (7) pg 7/18 : remove R232 - 10k for batt_temp_mon pullup
  • (8) pg 7/18 : remove R245 - 220 ohm for mtr_temp_mon pullup
  • (10) pg 7/18 : R206, R216 -> 6.66k to scale range 0-5V to 0-3.0V (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
  • (11) pg 7/18 : bridge current sensor use same values phase U,V


  • (12) Pg 8/18 : increase size of resisters (by 10x) for supply voltage measurement (R91, R94, R221, R88). Keep cut off freq the same.
  • (13) pg 8/18 : populate so measurement of supply voltage is default (R222, R233 installed). its easier to remove components than to add them.


  • (15) pg 6/18 : replace HALL_C input with SSI_CLK 5V output
  • (16) pg 11/18 : (CB) need to determine the accuracy of the RTC. Seems to be drifting.
  • (17) pg 18/18 : Remove LSSGA before TP56
  • (18) Connect TP56 to LSSGA connector. needs to protect dsPIC, but no other circuity.
    • adjust C95 for 15khz cutoff freq
  • (19) pg 14/18 : Connect TP252 to LSSGA connector. Needs to protect dsPIC, but no other circuity.


  • (20) 3/18 : LSSGA connector signals:
    • AGND
    • A3V ref (analog 3.0V reference)
    • A 3V supply ????
      • Think I mean a 3.3V supply that can supply working current. The reference can't (shouldn't) supply power for components.
    • TP56 analog in
    • TP252 analog in


  • locate IMU header for easier access. possibly rot180 - or move 2mm away from edge.
    • KS - lower position for V2.
    • CB - in V2 appears to be much more space in the shell, no other changes may be needed.

IMU

  • probably want to upgrade dual axis IMU
  • battery measurement circuit needs to be re-done.
Retrieved from "https://mediawiki.dideas.com/index.php?title=Rev200_mods&oldid=4921"