Audi System fr VR/AR Glasses Features Bluetth 1 cntrller cmpliant t Bluetth specificatin V4.1 Supprt A2DP and HFP prfiles Operating Vltage frm a 3.6V battery Battery charging with micr USB Wide audi bandwidth Battery Lifetime (typical) 2 Hurs (cntinuus music stream) Applicatins Eye ware 2 AR Glasses 2 Descriptin The Icaste is a fully-integrated Audi system that can be placed inside eyeware temples. The max required thickness t integrate the system is 5mm It features a Bluetth cntrller, 2 wfers, 4 MEMS tweeters, 2 Micrphnes (with beam frming), a pwer management that allws peratins using batteries with typical 3.6 V pwer supply, 32bit lw pwer micr-cntrller (ARM Crtex-M4). USund delivers the mdule with pre-sert audi filters, using the micr cntrller it is pssible t mdify and adapt the filters t custmer specific requirements VR Glasses Other kinds f wearable 1 Bluetth is a trademark wned by the Bluetth Special Interest Grup (SIG) 2 Due t exclusivity agreement the availability f samples is restricted and subject t third party apprval 1
Table f cntents 1 INTRODUCTION... 3 2 BLOCK DIAGRAM... 3 2.1 LEFT TEMPLE:... 3 2.2 RIGHT TEMPLE:... 3 3 BILL OF MATERIALS (BOM)... 5 3.1 RIGHT PCB... 5 3.2 LEFT PCB... 6 4 OPERATING CONDITIONS... 7 5 AUDIO CHARACTERISTICS... 7 5.1 SPL @10CM... 7 5.2 THD TYPICAL... 8 5.3 POLAR PATTERNS... 8 5.3.1 Radiatin n the hrizntal plane. Left temple. Frnt prt pinting at 0... 8 5.3.2 Radiatin n the vertical plane. Left temple. Frnt prt pinting at 0... 9 6 FUNCTIONS... 9 6.1 VOICE CALL... 9 6.2 AUDIO LISTENING... 10 6.3 BATTERY LOW... 10 6.4 CHARGING... 10 6.5 BLUETOOTH PAIRING... 11 6.6 TURN-ON AND TURN-OFF... 11 6.6.1 Turn-n... 11 6.6.2 Turn-ff... 12 7 BUTTON FUNCTIONS... 12 8 FIRMWARE UPDATE... 12 2
1 Intrductin The Icaste is a fully-integrated Audi system that can be placed inside eyeware temples. The max required thickness t integrate the system is 5mm It features a Bluetth cntrller, 2 wfers, 4 MEMS tweeters, 2 Micrphnes (with beam frming), a pwer management that allws peratins using batteries with typical 3.6 V pwer supply, 32bit lw pwer micr-cntrller (ARM Crtex-M4). USund delivers the mdule with pre-sert audi filters, using the micr cntrller it is pssible t mdify and adapt the filters t custmer specific requirements 2 Blck Diagram 2.1 Left temple: 2 Micrphnes Bluetth Fr picking up wn vice during phne calls, 2 mics fr beam frming Fr wireless audi play back, fr vice / phne calls, i.e. wireless cnnectin t smartphne Micrprcessr/DSP Fr running beam frming algrithm, filter functins, etc. Audi amplifiers/drivers/dac Pwer amplifiers DAC (if required) and drivers fr wfer & tweeters Ludspeakers (2 MEMS tweeter, 1 electr dynamical wfer) 2.2 Right Temple: On/ff switch Fr turning n and ff, fr Bluetth pairing (if required) Micr USB cnnectr Battery Fr charging the rechargeable battery in the glasses Rechargeable Lithium In battery Battery management Fr prviding suitable vltages fr individual blcks, fr generating pwer n reset, fr handling the battery charging Audi amplifiers/drivers/dac Pwer amplifiers, DAC (if required) and drivers fr wfer & tweeters Ludspeakers (2 MEMS tweeter, 1 electr dynamical wfer) 3
4
3 Bill f materials (BOM) 3.1 Right PCB 5
3.2 Left PCB 6
4 Operating cnditins The typical perating cnditins fr the develpment kit are 0 C t 45 C 5 Audi characteristics 5.1 SPL @10cm SPL 10cm [db] 90 85 80 75 70 65 60 ICaste SPL 55 50 70 db @ 1 khz Max SPL 45 100 1.000 10.000 Frequency [Hz] 7
5.2 THD Typical ICaste THD 20 18 16 14 70 db @ 1 khz THD [%] 12 10 8 6 4 2 0 100 1.000 10.000 Frequency [Hz] 5.3 Plar Patterns 5.3.1 Radiatin n the hrizntal plane. Left temple. Frnt prt pinting at 0 8
5.3.2 Radiatin n the vertical plane. Left temple. Frnt prt pinting at 0 6 Functins 6.1 Vice call When the glasses are cnnected t a phne they enable yu t take calls. Upn receiving a call the glasses will play yur ringtne. Yu can accept the call by pressing the multi-functin buttn. End the call by again pressing the multi-functin buttn again. Side nte: Declining an incming call is nt implemented yet. Principle diagram fr Vice call use case. 9
6.2 Audi listening The glasses can play music that is played n yur Bluetth device (like a smartphne r a Bluetthenabled prtable music player). Yu can start and stp the music frm bth yur Bluetth device and frm the glasses. Press the multi-functin buttn t tggle play/pause. If yu listen t music and receive an incming call at the same time, the music will autmatically pause. After ending the call, the music will autmatically start again. Principle diagram fr Audi listening use case. 6.3 Battery lw During music playback, the battery will last mre than 1 hur. The glasses will emit a warning sund apprximately 5 minutes befre the battery is depleted, and the LED will blink slwly. When the battery is depleted, the shutdwn sequence will autmatically initiate and the glasses will play the dwnwards meldy t cnfirm shutdwn. 6.4 Charging T recharge the battery, plug a Micr USB cable in the Micr USB slt lcated n the right temple and cnnect it t a suitable pwer supply (any pwered USB utlet will d, as will any USB pwer supply). The glasses will autmatically turn ff (if they haven t been turned ff befrehand) and g int charging mde, shwn by the blinking LED. As sn as the battery is cmpletely recharged, the LED stps blinking and illuminates cnstantly. Principle diagram fr Charging use case. 10
6.5 Bluetth pairing T pair the glasses with a new Bluetth device, the glasses need t be switched ff first. Then press the multi-functin buttn cntinuusly fr 5 secnds. After 3 secnds the start-up sequence will be initiated. Cntinue t press the multi-functin buttn until the pairing in prgress sund is played and the LED starts blinking. Nw select the glasses n yur ther Bluetth device (e.g. smartphne) t start the cnnectin. The blinking will stp when the glasses are crrectly paired with the ther Bluetth device. Side nte: There is n de-pairing functin; yu have the switch ff the glasses befre yu can pair the glasses t a different Bluetth device. Side nte fr iphne users: If yur mbile phne was nce cnnected with the glasses, but nt the latest device fr this glasses t be paired with, yu have t first delete the glasses ut f yur phnes recently used devices list. Nw the glasses will reappear like a new device and yu can crrectly start the pairing prcess. Principle diagram fr BT Pairing use case. 6.6 Turn-n and Turn-ff 6.6.1 Turn-n The electrnics is activated via the n/ff push buttn n the right temple. One shrt push will initiate the startup sequence. The pwer management unit will turn n and prvide the necessary vltages fr the rest f the system, it will prvide pwer n reset signals fr the micrcntrller/dsp. The micrcntrller/dsp will bt and lad its memry frm the Flash/EEPROM. Subsequently, the micrcntrller/dsp will activate the BT engine. If previusly paired t a BT master, and this BT master is transmitting, the BT link will be reestablished. If n autmatic cnnectin, a pairing event must be initiated. A pairing is initiated by hlding the push buttn fr 5 secnds. Pairing is acknwledged by 3 beeps in the left and right speakers. 11
6.6.2 Turn-ff The electrnics is de-activated via the n/ff push buttn n the right temple. If the system is already active, ne shrt push will initiate the turn ff sequence. In a battery lw scenari, the device will signal t the wearer that battery is lw by sunding 3 beeps. Once the battery reaches its battery empty state, the electrnics will autmatically turn ff. 7 Buttn functins Current status Buttn push Actin Sund LED Off 3 5s Turn n the glasses and recnnect t the last Bluetth device Off 5s Turn n the glasses and pair with a new Bluetth device Start-up, Recnnect Start-up; Cnnect Any n-state 3s Turn ff the glasses Shut-dwn - On & receiving a call 1s Accept call - - On & in a call 1s End call - - On & music paused On & music playing 1s Play music - - 1s Pause music - - flashing flashing 8 Firmware update Pssible ver Test-pints n the left temple 12
( USund ) makes n warranties fr the use f USund prducts, ther than thse expressly cntained in USund s applicable General Terms f Sale, lcated at USund assumes n respnsibility fr any errrs which may have crept int this dcument, reserves the right t change devices r specificatins detailed herein at any time withut ntice, and des nt make any cmmitment t update the infrmatin cntained herein. N license t patents r ther intellectual prperty rights f USund are granted in cnnectin with the sale f USund prducts, neither expressly nr implicitly. In respect f the intended use f USund prducts by custmer, custmer is slely respnsible fr bserving existing patents and ther intellectual prperty rights f third parties and fr btaining, as the case may be, the necessary licenses. Imprtant nte: The use f USund prducts as cmpnents in medical devices and/r medical applicatins, including but nt limited t, safety and life supprting systems, where malfunctins f such USund prducts might result in damage t and/r injury r death f persns is expressly prhibited, as USund prducts are neither destined nr qualified fr use as cmpnents in such medical devices and/r medical applicatins. The prhibited use f USund prducts in such medical devices and/r medical applicatins is exclusively at eh risk f the custmer. 13