# ESP32 Multi-Channel Audio Host ## Description > ESP32-based multi-channel audio and haptic control system powered by an external 12 V input, engineered to drive 8 vibrotactile outputs and 2 speaker channels. The design includes integrated thermal monitoring and offers optional support for AUX and microSD audio sources, ensuring flexible multimedia and feedback applications in a compact, efficient platform. ## Project Details - **Owner:** whenyoung - **Created:** 4/4/2026 - **Last Updated:** 4/4/2026 - **Visibility:** Public - **Power Requirements:** External DC barrel input, nominal 12 V - **System Architecture:** ```mermaid flowchart TD DCIN[External DC Barrel Jack] --> PROTECT[Input Protection and Inrush Block] PROTECT --> AMP[High Current Amplifier Rail] PROTECT --> BUCK5[Primary Buck Regulator] BUCK5 --> DIG33[3V3 Digital and ESP32 Rail] BUCK5 --> ANA33[Filtered 3V3 Analog Sense Rail] subgraph CTRL [Digital and Control Block] ESP32[ESP32 Dual Mode Bluetooth] BLE[BLE App Control] BT[Bluetooth Classic Audio] UI[System Control and Safety Logic] end subgraph SRC [Audio Source Block] BT --> MIX[Audio Source Selection and Routing] AUX[Optional AUX Line In] --> MIX SD[Optional SD Playback] --> MIX end subgraph AMPBANK [Power Audio Block] MIX --> VIBDRV[8 Class D Vibrator Channels] MIX --> SPKDRV[2 Speaker Driver Channels] end subgraph THERM [Thermal Monitoring Block] TH1[Thermistor Channels 1 to 4] TH2[Thermistor Channels 5 to 8] MUX[Sense Filtering and ADC Front End] end DIG33 --> ESP32 DIG33 --> UI ANA33 --> TH1 ANA33 --> TH2 TH1 --> MUX TH2 --> MUX MUX --> ESP32 ESP32 --> VIBDRV ESP32 --> SPKDRV AMP --> VIBDRV AMP --> SPKDRV ``` - **Operating Voltage:** 12 V nominal input; 3.3 V digital and analog rails - **Implementation Details:** Phase 1 schematic draft: nominal rails = VIN 12 V, PVDD 12 V high-current audio rail, +3V3_DIG buck rail 500 mA budget, +3V3_ANA filtered sense rail 100 mA budget. Recommended topology: two quad Class-D stages for 8 vibrotactile outputs plus one stereo Class-D stage for 2 speaker outputs. ESP32 module and MCU interfaces use placeholder net names pending final pin map. Thermistor front end uses 8 channels with divider/filtering and ADC or mux block placeholder. Optional AUX and microSD blocks included as placeholders. Maintain digital/RF isolation from Class-D switching/high-current return paths. ## Key Components ### D1 — [M7-Diode](https://www.flux.ai/openpartlist/m7-diode~5v.md) - Role Details: Series reverse-polarity protection placeholder on VIN path - Package: SMA - Datasheet URL: https://https://diotec.com/tl_files/diotec/files/pdf/datasheets/m1.pdfwww.taiwansemi.com/assets/uploads/datasheet/SK32A%20SERIES_V2102.pdf - Manufacturer Part Number: M7 - Role: Reverse Protection - License: https://creativecommons.org/licenses/by/4.0/ - Part Type: Diode - Manufacturer Name: Diotec Semiconductor **Pins:** - A [pin 2] - K [pin 1] ### F1 — [2016L050MR](https://www.flux.ai/adrian95/2016l050mr~9r5.md) - Current Rating: 20A - License: https://creativecommons.org/licenses/by/4.0/ - Manufacturer Part Number: 2016L050MR - Part Type: Fuse - Role: Input Protection - Package: 2016 - Role Details: Resettable fuse placeholder for DC input overcurrent protection - Datasheet URL: https://www.littelfuse.com/assetdocs/littelfuse_ptc_2016l_datasheet.pdf?assetguid=0a3f187e-62df-469f-85be-57fe3e3b4668 - Manufacturer Name: Littelfuse Inc. **Pins:** - P1 [pin 1] - P2 [pin 2] ### IC1 — [TPA3251D2DDVR](https://www.flux.ai/vasyl/tpa3251d2ddvr~o5.md) - Datasheet URL: https://www.ti.com/general/docs/suppproductinfo.tsp?distId=10&gotoUrl=https%3A%2F%2Fwww.ti.com%2Flit%2Fgpn%2Ftpa3251 - Role: Class-D Amplifier - Implementation Details: Stereo Class-D speaker amplifier placeholder. Assign SPK_L and SPK_R in later iteration. Keep physically separated from ESP32 RF and thermistor analog front end. - Manufacturer Name: Texas Instruments - Role Details: Stereo amplifier placeholder for left/right speaker outputs - Package: HTSSOP-44 - Manufacturer Part Number: TPA3251D2DDVR - Part Type: Integrated Circuit **Pins:** - ~CLIP_OTW [pin 21] - ~FAULT [pin 19] - ~RESET [pin 18] - AVDD [pin 14] - BST_A [pin 44] - BST_B [pin 43] - BST_C [pin 24] - BST_D [pin 23] - C_START [pin 15] - DVDD [pin 11] - FREQ_ADJ [pin 8] - GND [pin 41] - GND [pin 13] - GND [pin 42] - GND [pin 25] - GND [pin 33] - GND [pin 12] - GND [pin 26] - GND [pin 34] - GVDD_AB [pin 1] - GVDD_CD [pin 22] - INPUT_A [pin 5] - INPUT_B [pin 6] - INPUT_C [pin 16] - INPUT_D [pin 17] - M1 [pin 3] - M2 [pin 4] - OC_ADJ [pin 7] - OSC_IOM [pin 9] - OSC_IOP [pin 10] - OUT_A [pin 40] - OUT_A [pin 39] - OUT_B [pin 35] - OUT_C [pin 32] - OUT_D [pin 28] - OUT_D [pin 27] - PVDD_AB [pin 38] - PVDD_AB [pin 37] - PVDD_AB [pin 36] - PVDD_CD [pin 31] - PVDD_CD [pin 29] - PVDD_CD [pin 30] - VBG [pin 20] - VDD [pin 2] ### J1 — [PJ-051AH](https://www.flux.ai/vasy_skral/pj-051ah~yy8.md) - Datasheet URL: https://www.cuidevices.com/product/resource/digikeypdf/pj-051ah.pdf - Role: Power Input - Package: Through Hole - Role Details: Nominal 12 V external DC barrel jack, main power entry - Manufacturer Name: CUI Devices - Part Type: Connector - Manufacturer Part Number: PJ-051AH **Pins:** - Center Pin [pin 1] - MountPin [pin MP1] - MountPin [pin MP2] - Switch [pin 3] - Terminal [pin 2] ### J2 — [SJ-3524-SMT-TR-GR](https://www.flux.ai/cherepanyadima/sj-3524-smt-tr-gr~nz.md) - Package: SMT - Manufacturer Part Number: SJ-3524-SMT-GR - Datasheet URL: https://www.sameskydevices.com/product/resource/sj-352x-smt.pdf - Role Details: Optional 3.5 mm stereo AUX line input - Manufacturer Name: Same Sky (Formerly CUI Devices) - Part Type: Connectors - Mount: Surface Mount - Role: Audio Input Connector **Pins:** - ring [pin 3] - sleeve [pin 1] - tip [pin 2] - tip switch [pin 4] ### J3 — [MEM2085](https://www.flux.ai/digitalninjae/mem2085~n6.md) - Manufacturer Part Number: MEM2085-00-115-00-A - Role: Storage Connector - Datasheet URL: https://gct.co/files/drawings/mem2085.pdf - Role Details: Optional microSD playback storage placeholder - Part Type: SD Card - Implementation Details: Optional microSD playback support placeholder. SPI/SDIO net assignment deferred to future pin mapping. - Manufacturer Name: GCT - Package: SMT **Pins:** - CD - GND 1 [pin G1] - GND 10 [pin G10] - GND 2 [pin G2] - GND 3 [pin G3] - GND 4 [pin G4] - GND 5 [pin G5] - GND 6 [pin G6] - GND 7 [pin G7] - GND 8 [pin G8] - GND 9 [pin G9] - P1 [pin DAT2] - P2 [pin CD/DAT3] - P3 [pin CMD] - P4 [pin VDD] - P5 [pin CLK] - P6 [pin VSS] - P7 [pin DAT0] - P8 [pin DAT1] ### U1 — [AP63203WU-7](https://www.flux.ai/adrian95/ap63203wu-7~o8a.md) - Datasheet URL: https://www.diodes.com/assets/Datasheets/AP63200-AP63201-AP63203-AP63205.pdf - Role: Buck Regulator - Part Type: Integrated Circuit - Manufacturer Part Number: AP63203WU-7 - License: https://creativecommons.org/licenses/by/4.0/ - Package: TSOT-23-6 - Role Details: 12 V to 3.3 V digital rail regulator, 500 mA budget target - Manufacturer Name: Diodes Incorporated **Pins:** - BST [pin 6] - EN [pin 2] - FB [pin 1] - GND [pin 4] - SW [pin 5] - VIN [pin 3] ### U2 — [ESP32-WROVER-B](https://www.flux.ai/lcsc/esp32-wrover-b~zvrg.md) - JLCPCB Part Class: Extended Part - Package: Module - Part Type: WiFi Modules - Product Info Url: https://lcsc.com/product-detail/WIFI-Modules_Ai-Thinker-ESP32-WROVER-B_C503591.html - Manufacturer Name: ESPRESSIF(乐鑫) - Manufacturer Part Number: ESP32-WROVER-B - Role Details: ESP32 control, Bluetooth audio/control host, placeholder pin map pending - Package or Case Code: WIFIM-SMD_39P-L31.4-W18.0-P1.27 - Role: MCU Platform - LCSC Part Number: C503591 - Implementation Details: Placeholder MCU nets to be assigned later: MCU_I2S_BCLK, MCU_I2S_LRCLK, MCU_I2S_DOUT_VIB, MCU_I2S_DOUT_SPK, MCU_I2S_DIN_AUX, MCU_I2C_SCL, MCU_I2C_SDA, MCU_SD_CLK, MCU_SD_CMD, MCU_SD_D0, MCU_THRM_SEL0, MCU_THRM_SEL1, MCU_THRM_SEL2, MCU_THRM_ADC, MCU_AMP_MUTE, MCU_AMP_FAULT, MCU_BOOT, MCU_EN - Datasheet URL: https://storage.googleapis.com/graviton-electric-symbols/document_assets/lcsc/2004070932_Espressif-Systems-ESP32-WROVER-B_C503591.pdf **Pins:** - CLK [pin 20] - CMD [pin 19] - EN [pin 3] - GND [pin 15] - GND [pin 1] - GND [pin 39] - GND [pin 38] - IO0 [pin 25] - IO12 [pin 14] - IO13 [pin 16] - IO14 [pin 13] - IO15 [pin 23] - IO18 [pin 30] - IO19 [pin 31] - IO2 [pin 24] - IO21 [pin 33] - IO22 [pin 36] - IO23 [pin 37] - IO25 [pin 10] - IO26 [pin 11] - IO27 [pin 12] - IO32 [pin 8] - IO33 [pin 9] - IO34 [pin 6] - IO35 [pin 7] - IO4 [pin 26] - IO5 [pin 29] - NC [pin 27] - NC [pin 32] - NC [pin 28] - RXD0 [pin 34] - SD0 [pin 21] - SD1 [pin 22] - SD2 [pin 17] - SD3 [pin 18] - SENSOR_VN [pin 5] - SENSOR_VP [pin 4] - TXD0 [pin 35] - VDD33 [pin 2] ### U3 — [TAS5711PHP](https://www.flux.ai/adrian95/tas5711php~phf.md) - Manufacturer Part Number: TAS5711PHP - Role Details: Quad amplifier placeholder for vibrotactile output bank; use two devices for eight channels - Role: Class-D Amplifier - Datasheet URL: https://www.ti.com/lit/ds/symlink/tas5711.pdf - Implementation Details: Quad Class-D vibrotactile amplifier placeholder. Assign four vibrator channels VIB1 to VIB4 in later iteration. Power from PVDD_12V; digital/control/audio interface TBD. - Package: HTQFP-48 - Part Type: Integrated Circuit - Manufacturer Name: Texas Instruments - License: https://creativecommons.org/licenses/by/4.0/ **Pins:** - *RESET [pin 25] - A_SEL [pin 14] - AGND [pin 30] - AVDD [pin 13] - AVSS [pin 9] - BST_A [pin 4] - BST_B [pin 43] - BST_C [pin 42] - BST_D [pin 33] - DVDD [pin 27] - DVSS [pin 28] - DVSSO [pin 17] - EPAD [pin EPAD] - GND [pin 29] - GVDD_OUT [pin 32] - GVDD_OUT [pin 5] - LRCLK [pin 20] - MCLK [pin 15] - OC_ADJ [pin 7] - OSC_RES [pin 16] - OUT_A [pin 1] - OUT_B [pin 46] - OUT_C [pin 39] - OUT_D [pin 36] - PBTL [pin 8] - PDN [pin 19] - PGND_AB [pin 48] - PGND_AB [pin 47] - PGND_CD [pin 38] - PGND_CD [pin 37] - PLL_FLTM [pin 10] - PLL_FLTP [pin 11] - PVDD_A [pin 3] - PVDD_A [pin 2] - PVDD_B [pin 44] - PVDD_B [pin 45] - PVDD_C [pin 41] - PVDD_C [pin 40] - PVDD_D [pin 34] - PVDD_D [pin 35] - SCL [pin 24] - SCLK [pin 21] - SDA [pin 23] - SDIN [pin 22] - SSTIMER [pin 6] - STEST [pin 26] - VR_ANA [pin 12] - VR_DIG [pin 18] - VREG [pin 31] ### U4 — [TAS5711PHP](https://www.flux.ai/adrian95/tas5711php~phf.md) - Part Type: Integrated Circuit - Role Details: Quad amplifier placeholder for vibrotactile output bank; use two devices for eight channels - Implementation Details: Quad Class-D vibrotactile amplifier placeholder. Assign four vibrator channels VIB5 to VIB8 in later iteration. Power from PVDD_12V; digital/control/audio interface TBD. - Role: Class-D Amplifier - Package: HTQFP-48 - Manufacturer Name: Texas Instruments - License: https://creativecommons.org/licenses/by/4.0/ - Manufacturer Part Number: TAS5711PHP - Datasheet URL: https://www.ti.com/lit/ds/symlink/tas5711.pdf **Pins:** - *RESET [pin 25] - A_SEL [pin 14] - AGND [pin 30] - AVDD [pin 13] - AVSS [pin 9] - BST_A [pin 4] - BST_B [pin 43] - BST_C [pin 42] - BST_D [pin 33] - DVDD [pin 27] - DVSS [pin 28] - DVSSO [pin 17] - EPAD [pin EPAD] - GND [pin 29] - GVDD_OUT [pin 32] - GVDD_OUT [pin 5] - LRCLK [pin 20] - MCLK [pin 15] - OC_ADJ [pin 7] - OSC_RES [pin 16] - OUT_A [pin 1] - OUT_B [pin 46] - OUT_C [pin 39] - OUT_D [pin 36] - PBTL [pin 8] - PDN [pin 19] - PGND_AB [pin 48] - PGND_AB [pin 47] - PGND_CD [pin 38] - PGND_CD [pin 37] - PLL_FLTM [pin 10] - PLL_FLTP [pin 11] - PVDD_A [pin 3] - PVDD_A [pin 2] - PVDD_B [pin 44] - PVDD_B [pin 45] - PVDD_C [pin 41] - PVDD_C [pin 40] - PVDD_D [pin 34] - PVDD_D [pin 35] - SCL [pin 24] - SCLK [pin 21] - SDA [pin 23] - SDIN [pin 22] - SSTIMER [pin 6] - STEST [pin 26] - VR_ANA [pin 12] - VR_DIG [pin 18] - VREG [pin 31] ### U5 — [74HC4051D,653](https://www.flux.ai/giulioz/74hc4051dc653~8u.md) - Package: SOIC-16 - Implementation Details: 8-channel thermistor scan front-end placeholder. Thermistor nodes THERM_1 through THERM_8 feed mux channels; output routes to MCU_THRM_ADC in later pin-map phase. - Manufacturer Part Number: 74HC4051D,653 - Role Details: Eight-channel thermistor scan front end placeholder to MCU ADC - Role: Analog Multiplexer **Pins:** - ~E [pin 6] - GND [pin 8] - S0 [pin 11] - S1 [pin 10] - S2 [pin 9] - VCC [pin 16] - VEE [pin 7] - Y0 [pin 13] - Y1 [pin 14] - Y2 [pin 15] - Y3 [pin 12] - Y4 [pin 1] - Y5 [pin 5] - Y6 [pin 2] - Y7 [pin 4] - Z [pin 3] ### U6 — [PCM1808PWR](https://www.flux.ai/jecstronic/pcm1808pwr~xm.md) - Package: TSSOP-14 - Role: Audio ADC - Datasheet URL: https://www.ti.com/lit/ds/symlink/pcm1808.pdf - Part Type: Integrated Circuit - Manufacturer Name: Texas Instruments - Manufacturer Part Number: PCM1808PWR - Role Details: Optional stereo AUX capture to I2S placeholder - Implementation Details: Optional AUX stereo ADC placeholder. Interface nets to be assigned later as MCU_I2S_DIN_AUX and related clocks/control. - License: https://creativecommons.org/licenses/by/4.0/ **Pins:** - AGND [pin 2] - BCK [pin 8] - DGND [pin 5] - DOUT [pin 9] - FMT [pin 12] - LRCK [pin 7] - MD0 [pin 10] - MD1 [pin 11] - SCKI [pin 6] - VCC [pin 3] - VDD [pin 4] - VINL [pin 13] - VINR [pin 14] - VREF [pin 1] *The full schematic, PCB layout, bill of materials, and interactive design are available at [https://www.flux.ai/whenyoung/esp32-multi-channel-audio-host~8k](https://www.flux.ai/whenyoung/esp32-multi-channel-audio-host~8k).* --- *Generated from [https://www.flux.ai/whenyoung/esp32-multi-channel-audio-host~8k](https://www.flux.ai/whenyoung/esp32-multi-channel-audio-host~8k)*