?????? ? revision: ? a ?? release ? level: ? active ? sheet ? 1 ? of ? 5 ?? ? ?2011 ? knowles ? electronics ? kj \ 33000 \ 002 ? ? ? ? ? ? ? ? ? ? joystick ? i 2 c ? development ? kit ? programming ? and ? application ? note ? ? ? ? ? ? ? ? ? knowles ? acoustics ? 1151 ? maplewood ? drive ? itasca, ? il ? 60143 ? kj \ 33000 ? installed ? within ? the ? development ? kit. ?
?????? ? revision: ? a ?? release ? level: ? active ? sheet ? 2 ? of ? 5 ?? ? ?2011 ? knowles ? electronics ? kj \ 33000 \ 002 ? 1. description ? and ? application ? ? 1.1. description ? the ? kj \ 33000 \ 002 ? is ? a ? developer?s ? kit ? that ? includes ? the ? installed ? kj \ 3300 ? joystick. ??? the ? joystick ? is ? a ? digital ? joystick ? that ? communicates ? via ? an ? i 2 c ? interface. ? this ? application ? note ? describes ? how ? to ? communicate ? with ? the ? joystick. ? ? 1.2. application ? the ? joystick ? is ? developed ? for ? hand ? held ? telecommunication ? and ? electronic ? devices. ?? refer ? to ? manufacturer?s ? website ? ( www.knowles.com ) ? for ? current ? application ? notes. ? ? 2. i 2 c ? interface ? the ? i 2 c ? controller ? can ? operate ? up ? to ? 400khz ? (fast ? mode). ? seven \ bit ? addressing ? is ? implemented. ? the ? preprogrammed ? i 2 c ? address ? is ? 0x38. ? if ? the ? addr ? line ? is ? tied ? to ? v dd , ? the ? device ? will ? respond ? to ? address ? 0x39. ? ? a ? read ? initiated ? from ? the ? device ? returns ? two ? bytes. ? the ? first ? byte ? contains ? a ? left ? justified ? 4 ? bit ? value ? for ? the ? x ? axis ? while ? the ? second ? byte ? contains ? a ? left ? justified ? 4 ? bit ? value ? for ? the ? y ? axis. ? the ? least ? significant ? 4 ? bits ? of ? both ? bytes ? are ? zero ? filled. ? ? a ? write ? initiated ? to ? the ? device ? will ? send ? it ? into ? either ? low ? power ? mode ? or ? sleep ? mode ? depending ? on ? the ? value ? of ? the ? least ? significant ? bit. ? a ? ?1? ? corresponds ? to ? low ? power ? mode ? while ? a ? ?0? ? corresponds ? to ? sleep ? mode. ? ? the ? open ? drain ? interrupt ? line ? is ? asserted ? (low ? level) ? on ? a ? change ? in ? either ? the ? x ? or ? y ? value. ? no ? interrupts ? are ? generated ? when ? there ? are ? consecutive ? zeros ? on ? both ? axes. ? ? 3. programming ? examples ? 3.1. communication ? to ? the ? joystick ? communicating ? with ? the ? joystick ? using ? the ? i 2 c ? bus, ? simply ? send ? the ? start ? condition, ? send ? the ? address ? of ? the ? device ? (0x38 ? or ? 0x39 ? based ? on ? the ? addr ? pin) ? indicating ? a ? read ? operation. ? when ? an ? idle ? condition ? exists, ? read ? a ? byte ? from ? the ? device ? ( ? x ? displacement ? ), ? issue ? an ? acknowledgement, ? then ? on ? the ? next ? idle, ? read ? another ? byte ? from ? the ? device ? ( ? y \ displacement ? ). ? finally, ? issue ? a ? no \ acknowledgement, ? wait ? for ? an ? idle ? condition ? and ? issue ? a ? stop ? condition. ?
?????? ? revision: ? a ?? release ? level: ? active ? sheet ? 3 ? of ? 5 ?? ? ?2011 ? knowles ? electronics ? kj \ 33000 \ 002 ? ? sample: ? ??? idlei2c ? (); ????????????????? // ? wait ? for ? an ? idle ? condition ? ??? starti2c ? (); ???????????????? // ? issue ? a ? start ? condition ? ??? idlei2c ? (); ????????????????? // ? wait ? for ? an ? idle ? condition ? ??? address ? = ? 0x38 ? << ? 1 ? | ? 0x01; ? // ? joystick ? address ? plus ? read ? ??? ack ? = ? writei2c ? (address); ??? // ? write ? the ? address ? plus ? read ? ??? idlei2c ? (); ????????????????? // ? wait ? for ? an ? idle ? condition ? ??? joystickx ? = ? readi2c ? (); ????? // ? read ? joystick ? x ? displacement ? ??? acki2c ? (); ?????????????????? // ? issue ? an ? acknowledge ? condition ? ??? idlei2c ? (); ????????????????? // ? wait ? for ? an ? idle ? condition ? ??? joysticky ? = ? readi2c ? (); ????? // ? read ? joystick ? y ? displacement ? ??? notacki2c ? (); ??????????????? // ? issue ? the ? no \ ack ? condition ? ??? idlei2c ? (); ????????????????? // ? wait ? for ? an ? idle ? condition ? ??? stopi2c ? (); ????????????????? // ? release ? the ? bus ? ? 3.2. lookup ? tables ? lookup ? tables ? can ? be ? used ? to ? translate ? the ? displacement ? data ? to ? a ? more ? meaningful ? value. ? the ? x ? and ? y ? data ? in ? the ? previous ? example ? will ? be ? found ? in ? the ? most ? significant ? 4 ? bits ? of ? the ? variables ? joystickx ? and ? joysticky. ? these ? values ? can ? be ? simply ? bit ? shifted ? right ? by ? 4 ? bits ? using ? the ? bitwise ? >> ? operator. ? ? ? joystickx ? = ? joystickx ? >> ? 4; ? joysticky ? = ? joysticky ? >> ? 4; ? ? each ? of ? the ? joystick ? variables ? is ? now ? a ? number ? between ? 0 ? and ? 15 ? (4 ? bits). ? a ? lookup ? table ? consisting ? of ? a ? simple ? 16 ? byte ? array ? could ? be ? used ? to ? translate ? the ? value ? output ? by ? the ? joystick ? to ? a ? more ? relevant ? number. ? for ? example, ? the ? array: ? ? char ? xspeed[16] ? = ? {0,1,2,3,4,5,6,7,0, \ 1, \ 2, \ 3, \ 4, \ 5, \ 6, \ 7}; ? ? would ? be ? used ? to ? translate ? the ? actual ? output ? of ? the ? device ? to ? a ? real, ? displacement ? number. ?? ? please ? note ? that ? due ? to ? the ? most ? significant ? bit ? indicating ? positive ? or ? negative ? displacement, ? there ? are ? 2 ? possibilities ? of ? zero ? in ? the ? joystick. ? 0b1000 ? is ? the ? same ? as ? 0b0000. ? the ? data ? in ? the ? array ? will ? then ? translate ? actual ? displacement ? to ? a ? number ? corresponding ? to ? the ? physical ? position ? of ? the ? stick. ? ? lookup ? tables ? could ? also ? be ? used ? to ? expand ? the ? 4 ? bit ? value ? to ? a ? signed ? 8 ? bit ? value. ? for ? example: ?
?????? ? revision: ? a ?? release ? level: ? active ? sheet ? 4 ? of ? 5 ?? ? ?2011 ? knowles ? electronics ? kj \ 33000 \ 002 ? ? ?????? char ? xspeed[16] ? = ? {0,15,31,47,63,79,95,111,0, \ 15, \ 31, \ 47, \ 63, \ 79, \ 95, \ 111}; ? ? ? linearly ? expands ? the ? value ? output ? by ? the ? joystick ? by ? indexing ? the ? joystickx ? value ? in ? the ? array. ? ? lookupxspeed ? = ? xspeed[joystickx]; ? ? 3.3. low ? power ? modes ? there ? are ? two ? low ? power ? modes ? to ? the ? joystick; ? low ? power ? and ? sleep ? mode. ??? to ? put ? the ? joystick ? into ? low ? power ? mode, ? a ? simple ? write ? to ? the ? joystick ? with ? the ? least ? significant ? bit ? being ? a ? one ? is ? required. ? to ? put ? the ? joystick ? into ? sleep ? mode, ? the ? least ? significant ? bit ? of ? the ? write ? must ? be ? a ? zero. ?? ? sample: ? ? ??? idlei2c ? (); ????????????????? // ? wait ? for ? an ? idle ? condition ? ??? starti2c ? (); ???????????????? // ? issue ? a ? start ? condition ? ??? idlei2c ? (); ????????????????? // ? wait ? for ? an ? idle ? condition ? ??? address ? = ? 0x38 ? << ? 1 ? | ? 0x00; ? // ? joystick ? address ? plus ? write ? ??? ack ? = ? writei2c ? (address); ??? // ? write ? the ? address ? plus ? read ? ??? idlei2c ? (); ????????????????? // ? wait ? for ? an ? idle ? condition ? ??? ack ? = ? writei2c ? (0); ????????? // ? put ? the ? joystick ? into ? low ? pwr ? ??? notacki2c ? (); ??????????????? // ? issue ? the ? no \ ack ? condition ? ??? idlei2c ? (); ????????????????? // ? wait ? for ? an ? idle ? condition ? ??? stopi2c ? (); ????????????????? // ? release ? the ? bus ? ? this ? example ? will ? put ? the ? joystick ? into ? sleep ? mode. ? the ? current ? consumption ? of ? the ? device ? will ? be ? at ? its ? minimum ? in ? this ? mode. ? ? ? ?
?????? ? revision: ? a ?? release ? level: ? active ? sheet ? 5 ? of ? 5 ?? ? ?2011 ? knowles ? electronics ? kj \ 33000 \ 002 ? ? 4. i 2 c ? demo ? board ? ? 4.1. clarification ? of ? pins ? for ? physical ? pin ? number, ? please ? see ? the ? product ? data ? sheet. ? av dd ?? \? analog ? power ? supply ? : ? 3.3v ? typical ? ? v io ? ? ? i/o ? power ? supply, ? 1.8v ? or ? connect ? to ? v dd ? test ? ? ? connect ? to ? ground ? addr ? ? ? gnd ? for ? address ? 0x38, ? v dd ? for ? address ? 0x39 ? scl ?\? i 2 c ? clock ? line ? int ? ? ? not ? necessary ? for ? operation, ? asserted ? at ? change ? of ? x ? or ? y ? sda ? ? ? i 2 c ? data ? line ? v pp ? ? ? programming ? power ? supply: ? connect ? to ? vdd ? v ss ? ? ? digital ? ground ?? v dd ? ? ? digital ? power ? supply: ? 3.3v ? typical ? ? n/c ??\? no ? connection ? av ss ? ? ? analog ? ground ? ? corner ? pads ? ? ? connect ? to ? ground ? for ? best ? rf ? performance ? ? the ? information ? contained ? in ? this ? literature ? is ? based ? on ? our ? experience ? to ? date ? and ? is ? believed ? to ? be ? reliable ? and ? it ? is ? subject ? to ? change ? without ? notice. ? it ? is ? intended ? as ? a ? guide ? for ? use ? by ? persons ? having ? technical ? skill ? at ? their ? own ? discretion ? and ? risk. ? we ? do ? not ? guarantee ? favorable ? results ? or ? assume ? any ? liability ? in ? connection ? with ? its ? use. ? dimensions ? contained ? herein ? are ? for ? reference ? purposes ? only. ? for ? specific ? dimensional ? requirements ? consult ? factory. ? this ? publication ? is ? not ? to ? be ? taken ? as ? a ? license ? to ? operate ? under , ? or ? recommendation ? to ? infrin g e ? an y ? existin g ? p atents. ? this ? su p ersedes ? and ? voids ? all ? p revious ? literature. ?
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