Rev200 mods
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- SERIES: S01 S02 S03 wow_left wow_right
Contents
PCB needed Revisions
FET
- w/clamp circuit - use thermal vias for R4 - this device is impossible to replace
- will try low temp solder and send to MPD
- height of coin cells is too great. need the original coin cell spec
- 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
- 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]
- 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
- 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
- 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)
- 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
- 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.
- pg 3/18 : replace 1.25mm header for EC30 enc/hall w/ 12x0.8mm header
- 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.
- pg 18/18 : Remove LSSGA before TP56
- Connect TP56 to LSSGA connector. needs to protect dsPIC, but no other circuity.
- adjust C95 for 15khz cutoff freq
- pg 14/18 : Connect TP252 to LSSGA connector. Needs to protect dsPIC, but no other circuity.
- 3/18 : LSSGA connector signals:
- AGND
- A3V ref
- A 3V supply
- 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.