Upload
al-fredo
View
214
Download
0
Embed Size (px)
Citation preview
8/8/2019 Accelerometer App Note
1/6
\e` Wpo WQN\ l`jn w`own} mnc}l iogfpl`w co FIW7F1=CS cgg`f }nj`|`} |ec| gco m` pw`l |n j`cwp}`
|e` n}i`o|c|ino n} jn|ino nh |e` WQN\/ \eiw cqqfigc|ino on|` l`wg}im`w enr |n pw` col gcfim}c|` |e`
FIW7F1=CS cgg`f`}nj`|`}/
\e` FIW7F1=CS iw c fnr*qnr`}& |e}``*cuiw fio`c} cgg`f`}nj`|`} |ec| iw jnpo|`l no |e` l`jn w`own} mnc}l nh |e`
Wpo WQN\/ \e` cgg`f`}nj`|`} gco m` pw`l |n j`cwp}` |e` jn|ino nh |e` WQN\/ I| gco cfwn j`cwp}` |e` WQN\"w
n}i`o|c|ino ri|e }`wq`g| |n b}cxi|y/ \e` [*cuiw iw q`}q`oligpfc} |n |e` Wpo WQN\ mnc}lw/ \e` U*cuiw iw qc}cff`f |n
|e` }nr nh F@Lw no |e` w`own} mnc}l/ \e` Y*cuiw iw qc}cff`f |n |e` fnob `lb` nh |e` w`own} mnc}l/
Hibp}` 3/ Cgg`f`}nj`| } U& Y col [ cu`w
Io Hibp}` 3& |e` qfpw $) no |e` `ol nh co cuiw ioligc|`w |ec| re`o |e` l`xig`"w cgg`f`}c|ino x`g|n} iog}`cw`w io
|ec| li}`g|ino& |e` cwwngic|`l cgg`f`}nj`|`} }`cliobw riff b}nr fc}b`}/ Ih |e` WQN\ iw wi||iob hfc| no c |cmf` |e`o
|e` cgg`f`}c|ino lp` |n |e` @c}|e"w b}cxi|y riff m` 3b cfnob |e` qnwi|ix` [*cuiw& col 1b cfnob |e` U col Y cu`w/
On|` |ec| reif` b}cxi|y iw qnio|iob lnro cfnob |e` o`bc|ix` [*cuiw) |eiw iw `spixcf`o| |n c poihn}j pqrc}lw
cgg`f`}c|ino nh 3b cggn}liob |n |e` @iow|`io `spixcf`og` q}iogiqf` `x`o |enpbe |e` WQN\ iw on| jnxiob/
\e` FIW7F1=CS cgg`f`}nj`|`} gnowiw|w nh c Jig}n*@f`g|}n*J`gecoigcf Wyw|`j J@JW) w`own} `f`j`o| |ec| iw
liwqfcg`l h}nj i|w onjiocf qnwi|ino re`o c fio`c} cgg`f`}c|ino iw cqqfi`l& gcpwiob co `f`g|}igcf ijmcfcog` |ec|
iw }`cl xic |e` l`jn w`own} mnc}l"w cocfnb*|n*libi|cf gnox`}|`}/ \e` }cr xnf|cb` xcfp` iw |e`o gnox`}|`l |n
b*hn}g` poi|w/ \e` cgg`f`}nj`|`} gco m` w`| |n j`cwp}` cgg`f`}c|inow nx`} c wgcf` nh `i|e`} =b n} 8b/ Hn} c
hpff l`wg}iq|ino nh |e` |`geoigcf wq`gihigc|inow nh |e` FIW7F1=CS cgg`f`}nj`|`} qf`cw` }`h`} |n |e`
W\Jig}n`f`g|}noigw lngpj`o|c|ino cxcifcmf` c| e||q;..rrr/w|/gnj.w|nofio`.q}nlpg|w.fi|`}c|p}`.nl.97=3/qlh/
\e` WQN\ fim}c}y iogfpl`w mn|e |e` ICgg`f`}nj`|`}7L io|`}hcg` |ec| l`hio`w |e` mcwig j`|enlw |ec| coy
|e}``*cuiw cgg`f`}nj`|`} wenpfl wpqqn}|& col |e` FIW7F1=CSCgg`f`}nj`|`} gfcww |ec| ijqf`j`o|w |ec|
io|`}hcg` cfnob ri|e w`x`}cf n|e`} j`|enlw wq`gihig |n |e` FIW7F1=CS/
\e` Mcwig ICgg`f`}nj`|`}7L CQI
\e` mcwig j`|enlw pw`l |n }`cl |e` gp}}`o| cgg`f`}c|ino io B"w cfnob cge cuiw c}`b`|Cgg`fU%)&
b`|Cgg`fY%) col b`|Cgg`f[%)/ C hnp}|e j`|enl& b`|Cgg`f%)& }`|p}ow |e` jcboi|pl` nh |e` gp}}`o| |n|cf
cgg`f`}c|ino& c/ \eiw iw |e` x`g|n} wpj nh |e` cgg`f`}c|ino cfnob |e` U& Y ( [ cu`w& c: cu= cy
= c{
=/
Pwiob |e` FIW7F1=CS Cgg`f`}nj`|`}]no Bnfljco
C WPO WQN\ CQQFIGC\INO ON\@
?
8/8/2019 Accelerometer App Note
2/6
Qcb` = Pwiob |e` FIW7F1=CS Cgg`f`}nj`| }
E`}` iw c gnl` h}cbj`o| |ec| riff fnnq po|if |e` cgg`f`}c|ino cfnob |e` U*cuiw `ug``lw b;
ijqn}| gnj/wpo/wqn|/w`own}mnc}l/@L`jnMnc}l4ijqn}| gnj/wpo/wqn|/w`own}mnc}l/ICgg`f`}nj`|`}7l4ijqn}| gnj/wpo/wqn|/p|if/P|ifw4
ICgg`f`}nj`|`}7L cgg : @l`jnMnc}l/b`|Iow|cog`%)/b`|Cgg`f`}nj`|`}%)4
reif` %|}p`) tlnpmf` cu : cgg/b`|Cgg`fU%)4ih %cu ?: 1/=0) t
Wyw|`j/np|/q}io|fo%U cgg`f`}c|ino cmnx` |e}`wenfl; $ cu)4m}`cd4
zP|if/wf``q%=01)4 .. ge`gd `x`}y 3.< w`gnol
z
E`}`"w con|e`} h}cbj`o| |n l`|`g| re`o |e` WQN\ iw io jn|ino my ge`gdiob hn} |e` |n|cf cgg`f`}c|ino |n l`xic|`
h}nj |e` 3b nh b}cxi|y;
qpmfig mnnf`co iwJnxiob%) |e}nrw IN@ug`q|ino t
lnpmf` jcb : cgg/b`|Cgg`f%)4}`|p}o Jc|e/cmw%jcb 3/1) ?: 1/34
z
J`cwp}iob }`fc|ix` cgg`f`}c|ino
Con|e`} w`| nh j`|enlw& b`|]`fc|ix`Cgg`fU%)& b`|]`fc|ix`Cgg`fY%)& b`|]`fc|ix`Cgg`f[%) col
b`|]`fc|ix`Cgg`f%)& }`|p}o |e` gp}}`o| cgg`f`}c|ino }`fc|ix` |n c q}`xinpwfy j`cwp}`l cgg`f`}c|ino/ \eiw
cffnrw no` |n {`}n np| |e` hn}g` nh b}cxi|y no |e` WQN\ col j`cwp}` |e` }`fc|ix` cgg`f`}c|ino nofy/ \e`
j`|enl& w`|]`w|Nhhw`|w%)& gnjqp|`w |e` gp}}`o| cgg`f`}c|ino cfnob cge cuiw col wcx`w i|& w|cmfiweiob c
o`r {`}n }`cliob |n m` pw`l my |e` cmnx` j`|enlw/ E`}` iw |e` cmnx` gnl` `ucjqf` }`r}i||`o pwiob |e`
}`fc|ix` cgg`f`}c|ino }np|io`w;
cgg/w`|]`w|Nhhw`|w%)4 .. {`}n np| |e` gp}}`o| hn}g`w no |e` WQN\
qpmfig mnnf`co iwJnxiob%) |e}nrw IN@ug`q|ino t}`|p}o cgg/b`|]`fc|ix`Cgg`f%) ?: 1/34
z
J`cwp}iob |if|
C |ei}l w`| nh j`|enlw& b`|\if|U%)& b`|\if|Y%) col b`|\if|[%)& pw` |e` cgg`f`}c|ino cfnob co cuiw io n}l`}
|n gnjqp|` |e` iogfioc|ino& n} |if|& nh |ec| cuiw ri|e }`wq`g| |n |e` |n|cf cgg`f`}c|ino |e` WQN\ iw `uq`}i`ogiob/ Ih
|e` WQN\ iw c| }`w| |e`o |e` |if| iw j`cwp}`l ri|e }`wq`g| |n b}cxi|y/
Hibp}` =/ Gnjqp|iob |e` |if|
rrr/wpowqn|rn}fl/gnj
f`x`f
|n|cf cgg`f`}c|ino
cuiw
|if| cobf`
v vccuiw
8/8/2019 Accelerometer App Note
3/6
Qcb` 7 Pwiob |e` FIW7F1=CS Cgg`f`}nj`| }
Cw wenro io Hibp}` = |e` |if| cobf` gco m` gnjqp|`l cw : c}gwioccuiwc
re`}` iw |e` |if| cobf` j`cwp}`l
io }clicow ri|e c }cob` nh
=|n
=)& ccuiw iw |e` cgg`f`}c|ino j`cwp}`l cfnob |e` bix`o cuiw& col c iw
|e` |n|cf cgg`f`}c|ino/E`}` iw c gnl` `ucjqf` |n j`cwp}` |e` |if| nh |e` WQN\ col liwqfcy |e` |if| io |e` F@Lw fid` c mpmmf` io c f`x`f;
qpmfig xnil l`jnMpmmf`F`x`f%) thn} %io| i : 14 i 6 54 i$$) t
f`lwTiZ/w`|Nhh%)4 .. |p}o nhh cff F@Lwf`lwTiZ/w`|Gnfn}%F@LGnfn}/MFP@)4 .. w`| |e`j |n m` mfp` re`o fi|
z
reif` %|}p`) t|}y t
io| |if|U : %io|)Jc|e/|nL`b}``w%cgg/b`|\if|U%))4 .. }`|p}ow T*91& $91Zio| nhhw`| : *|if|U . 304 .. wn mpmmf` bn`w |n eibe`} wil` T8& *8Zih %nhhw`| 6 *7) nhhw`| : *74 .. gfiq cobf` |n }cob` T7& *7Zih %nhhw`| ? 7) nhhw`| : 74f`lwT7 $ nhhw`|Z/w`|No%)4 .. pw` = F@Lw |n liwqfcy -mpmmf`--
f`lwT< $ nhhw`|Z/w`|No%)4P|ifw/wf``q%01)4 .. pqlc|` =1 |ij`w q`} w`gnolf`lwT7 $ nhhw`|Z/w`|Nhh%)4 .. gf`c} liwqfcyf`lwT< $ nhhw`|Z/w`|Nhh%)4
z gc|ge %IN@ug`q|ino `u) tWyw|`j/np|/q}io|fo%-@}}n} }`cliob cgg`f`}nj`|`}; - $ `u)4
zz
z
\e` cmnx` `ucjqf` iw iow|cff`l ri|e |e` Wpo WQN\ WLD col gco m` hnpol io;
L`jnw.Gnl`Wcjqf`w.Cgg`f`}nj`|`}Wcjqf`Gnl`
Hn} jnw| WQN\ q}nb}cjw |e` hpog|inocfi|y l`hio`l my ICgg`f`}nj`|`}7L riff m` cff |ec| iw o``l`l/
\e` FIW7F1=CSCgg`f`}nj`|`}CQI
\e` FIW7F1=CS cgg`f`}nj`|`} gco m` w`| |n j`cwp}` cgg`f`}c|inow nx`} c wgcf` nh i|e`} =b n} 8b/ \e`
j`|enl w`|Wgcf`%io|) iw pw`l |n w`f`g| |e` l`wi}`l wgcf`/ i| |cd`w no` c}bpj`o|& `i|e`} |e` gnow|co|
WGCF@^=B n} WGCF@^8B/
ijqn}| gnj/wpo/wqn|/w`own}mnc}l/@L`jnMnc}l4ijqn}| gnj/wpo/wqn|/w`own}mnc}l/FIW7F1=CSCgg`f`}nj`|`}4
FIW7F1=CSCgg`f`}nj`|`} cgg :%FIW7F1=CSCgg`f`}nj`|`})@l`jnMnc}l/b`|Iow|cog`%)/b`|Cgg`f`}nj`|`}%)4
cgg/w`|Wgcf`%FIW7F1=CSCgg`f`}nj`|`}/WGCF@^=B)4 .. pw` |e` =B wgcf`
\e` j`|enl b`|Gp}}`o|Wgcf`%) }`|p}ow co io|`b`} `i|e`} WGCF@^=B n} WGCF@^8B) ioligc|iob reige wgcf` iw
gp}}`o|fy w`f`g|`l/ \e` j`|enl b`|Wgcf`w%) }`|p}ow co c}}cy nh io|`b`}w& t =& 8 z& |ec| fiw| |e` wgcf`w |e`
cgg`f`}nj`| } wpqqn}|w/ On|` |ec| |e` gnow|co|w&WGCF@^=B col WGCF@^8B& gco m` pw`l cw iolig`w io|n |eiw
c}}cy/ Wn ch|`} |e` gnl` woiqq`| cmnx` |n w`f`g| |e` =B wgcf`& |e` w|c|`j`o|;
io| wgcf` : cgg/b`|Wgcf`w%)Tcgg/b`|Gp}}`o|Wgcf`%)Z4
rnpfl w`| |e` xc}icmf` wgcf` |n c xcfp` nh =/
\e` j`|enlw b`|]crU%)& b`|]crY%) col b`|]cr[%) c}` pw`l |n b`| |e` }cr xnf|cb` xcfp`w }`cl h}nj `cge cuiw
nh |e` cgg`f`}nj`|`}/ \e`y }`|p}o c xcfp` io |e` }cob` 1 |n 31=7/ \n gnox`}| |eiw xcfp` |n B"w }`spi}`w |rn
rrr/wpowqn|rn}fl/gnj
8/8/2019 Accelerometer App Note
4/6
Qcb` < Pwiob |e` FIW7F1=CS Cgg`f`}nj`| }
w|`qw; wpm|}cg|iob nhh |e`{`}n nhhw`| xcfp` hn} |ec| cuiw reige riff weih| |e` }cob` |n nhhw`| |n $nhhw`|& col |e`o
lixiliob my |e` bcio hn} |e` cuiw |n wgcf` |e` xcfp` |n B"w/
c:}cr {`}nNhhw`|
bcio
\e` onjiocf {`}n nhhw`| xcfp` iw
8/8/2019 Accelerometer App Note
5/6
Qcb` 0 Pwiob |e` FIW7F1=CS Cgg`f`}nj`| }
|e` F@Lw no |e` f`h|)/ \e` WQN\ riff wibocf |ec| i| iw cmnp| |n |cd` c }`cliob hfcweiob F@Lw) col |e`o hn} `cge
cuiw |cd` |e` cx`}cb` nh 01 }`cliobw c| |e` =B wgcf`& col |e`o cbcio pwiob |e` 8B wgcf`/ Ih |e` WQN\"w q}io|
np|qp| iw m`iob liwqfcy`l& |e`o |e` jioijpj& jcuijpj col cx`}cb` xcfp`w hn} `cge cuiw col wgcf` riff m`
q}io|`l/ Re`o }`cliobw ecx` m``o |cd`o cfnob cff 8 n}i`o|c|inow |e` gnjqp|`l {`}n nhhw`|w col bciow xcfp`w
riff m` q}io|`l/
\eiw gcfim}c|ino q}ng`ww iw lno` |rig`/ \e` w`gnol |ij` pw`w |e` xcfp`w h}nj |e` hi}w| |n |ibe|`o |e` gnow|}cio|w
no rec| iw co cgg`q|cmf` n}i`o|c|ino/
Ch|`} |e` gcfim}c|ino q}ng`ww |e` cgg`f`}nj`|`} q`}hn}jw c w`fh |`w| mfp` F@Lw)qpwe wri|ge 3 |n w|c}|/ Ih i|
qcww`w |e`o |e` gcfim}c|ino xcfp`w& riff m` w|n}`l cw q`}wiw|`o| q}nq`}|i`w io |e` l`jn w`own} mnc}l"w Hfcwe
j`jn}y col pw`l re`o`x`} c WQN\ cqqfigc|ino pw`w |e` cgg`f`}nj`|`} io |e` hp|p}`/
C Rn}l no Wcjqfiob ]c|`w
\e` }c|` c| reige co cqqfigc|ino o``lw |n }`cl |e` cgg`f`}nj`|`} riff xc}y b}`c|fy col l`q`olw no |e` |yq` nh
cgg`f`}nj`| } lc|c m`iob j`cwp}`l/ Hn} co cqqfigc|ino gnog`}o`l ri|e j`cwp}iob |e` WQN\"w n}i`o|c|ino cwcjqf` }c|` nh 31*=1 }`cliobw q`} w`gnol riff pwpcffy wphhig`4 fid`riw` hn} b`w|p}` }`gnboi|ino/ Hn} j`cwp}iob
|e` jn|ino nh |e` WQN\ re`o jnpo|`l io c |ny wfn| gc}& c }c|` nh 311 }`cliobw q`} w`gnol rcw jn}` |eco
cl`spc|`/ Ih no` riwe`w |n j`cwp}` xim}c|inow |e`o |e` Oyspiw|*Wecoono wcjqfiob |e`n}`j |`ffw pw |ec| |e`
wcjqfiob h}`sp`ogy o``lw |n m` b}`c|`} |eco |rig` |e` wibocf mcolril|e/ \e` sp`w|ino |e`o iw enr eibe c
wcjqf` }c|` iw qnwwimf`/
Hibp}` 7 wenrw |e` xc}inpw gnjqno`o|w ioxnfx`l io }`cliob cgg`f`}nj`|`} xcfp`w/
Hibp}` 7/ Gnjqno`o|w ioxnfx`l io }`cliob |e` cgg`f`}nj`|`}
\e` J@JW w`own}w nh |e` FIW7F1=CS cgg`f`}nj`|`} c}` gcqcmf` nh j`cwp}iob cgg`f`}c|inow nx`} c jcuijpj
mcolril|e nh
8/8/2019 Accelerometer App Note
6/6
Qcb` 8 Pwiob |e` FIW7F1=CS Cgg`f`}nj`| }
cff |e}`` cu`w& n} =/=DE{/ \e`w` jcuijpj wcjqf` }c|`w c}` nofy qnwwimf` ih |e` WQN\ cqqfigc|ino iw 311%
l`ligc|`l |n }`cliob |e` cgg`f`}nj`|`}/ Ih coy n|e`} gnjqp|c|ino iw q`}hn}j`l io n|e`} |e}`clw |ec| riff
l`g}`cw` |e` wcjqf` }c|` col io|}nlpg` ki||`} io re`o wcjqf`w c}` |cd`o col qnwwimfy `x`o gcpw` jiww`l
wcjqf`w/
Qp||iob cff nh |e`w` hcg|n}w |nb`|e`} ijqfi`w |ec| |e` jcuijpj wcjqf` }c|` iw 7=1E{& n} wfibe|fy eibe`}& |n
jc|ge pq ri|e |e` gp|nhh h}`sp`ogy nh 381E{/ \eiw j`cow |cdiob c w`| nh }`cliobw `x`}y 7 /3=0 jiffiw`gnolw&
reige iw c }c|` |ec| gco m` wpw|cio`l col w|iff cffnr hn} n|e`} gnjqp|c|ino |n m lno`***iogfpliob }`cf*|ij`
cocfywiw nh |e` iognjiob cgg`f`}nj`|`} xcfp`w/ Ih }clin qcgd`|w c}` w`o| reif` }`cliob |e` cgg`f`}nj`|`}& i|
jibe| gcpw` c wcjqf` q`}inl |n m` jiww`l cw i| |cd`w cmnp| < jiffiw`gnolw |n w`ol c qcgd`|/ Wcjqf` }`cliobw
jcy cfwn m` fnw| lp` |n bc}mcb` gnff`g|ino& |enpbe wiog` c b`o`}c|inocf gnff`g|ino wge`j` iw pw`l my |e`
Wspcrd Kcxc XJ& |e` `uq`g|`l l`fcyw h}nj BG c}` nofy cmnp| =1*71 jiffiw`gnolw/
]`qfcgiob |e` gcqcgi|n} |n }ciw` |e` gp|nhh h}`sp`ogy |n 501E{ rnpfl cffnr cff |e}`` cu`w |n m` }`cl c| c
jcuijpj }c|` nh 3/2DE{/ Ih nofy c wiobf` cuiw o``lw |n m` }`cl |e`o i| wenpfl m` qnwwimf` |n }`cl no` gecoo`f
c| c }c|` nh 0DE{ ch|`} }ciwiob |e` gp|nhh h}`sp`ogy |n =/0DE{***|enpbe c| |eiw }c|` wcjqf`w gnpfl q}nmcmfy nofym` |cd`o hn} c fiji|`l |ij`/
On|`; \n f`c}o enr |n |cd` wcjqf`w c| }`bpfc} io|`}xcfw qf`cw` }`h`} |n |e` Wpo WQN\ Cqqfigc|ino On|` no Pwiob
|e` C\93 \ij`}.Gnpo|`}w/
rrr/wpowqn|rn}fl/gnj
Cmnp| Wpo Fcmw
@w|cmfiwe`l io 3991& Wpo Jig}nwyw|`jw Fcmn}c|n}i`w iw |e` cqqfi`l }`w`c}ge col clxcog`l l`x`fnqj`o| c}j nh
Wpo Jig}nwyw|`jw& Iog/& ri|e fngc|inow io Gcfihn}oic col Jcwwcgepw`||w/ Wpo Fcmw iw no` nh |e` rcyw Wpo iox`w|wio |e` hp|p}`& col iw }`wqnowimf` hn} jcoy nh |e` |`geonfnby clxcog`j`o|w |ec| ecx` jcl` Wpo c |`geonfnby
qnr`}enpw`iogfpliob cwyoge}nonpw col eibe*wq``l gi}gpi|w& nq|igcf io|`}gnoo`g|w& 7}l*b`o`}c|ino R`m
|`geonfnbi w& w`own}w& o`|rn}d wgcfiob col Kcxc |`geonfnbi`w/ Cf|enpbe jcoy gnjqcoi w ecx` ](L b}npqw&
Wpo Fcmw gco gfcij no` nh |e` eibe`w| }c|`w nh |`geonfnby |}cowh`} io |e` iolpw|}y/
Wpo Jig}nwyw|`jw& Iog/