T1AI-BOX Voice Solution

Tuya T1AI-BOX is a voice and screen multi-interaction AI box based on the T1-U-HL, an embedded Wi-Fi module developed by Tuya Smart. Equipped with one microphone, one audio loopback, and one speaker, this AI box supports voice recognition and playback, offering voice interaction capabilities.

Features

• Module: T1-U-HL.
  • 32-bit MCU @160 MHz.
  • 2 MB SiP flash memory.
  • 288 KB RAM.
• Voice chip: GX8006.
  • 32-bit RISC-V CPU.
  • 8 KB I-cache and 4 KB D-cache.
  • 176 KB SRAM.
• Audio: 2-channel 16-bit audio ADC and 1-channel audio DAC.
• Screen: 0.96-inch I2C screen.
• Wi-Fi:
  • IEEE 802.11b/g/n compliant.
  • Channels 1 to 14 at 2.4 GHz.
  • Support WEP, WPA/WPA2, WPA/WPA2 PSK (AES), and WPA3 security modes.
  • The maximum output power is +18 dBm for IEEE 802.11b transmission.
  • Support STA, AP, and STA + AP combo working modes.
  • Two pairing modes are supported, namely Wi-Fi Easy Connect (EZ mode) and access point (AP) mode. Both modes are available on Android and iOS devices.
• Bluetooth:
  • Bluetooth Core Specification v5.2.
  • The transmitter power in Bluetooth mode is 6 dBm.
  • Integral Wi-Fi and Bluetooth coexistence interface.

Functional block diagram

Peripherals

Recommended I/O configuration of I2C LCD

LCD subscreen parameters

Things to note

Antenna clearance

• Do not use metal shells or plastic shells with metallic painting or coating in the direction of the antenna radiation. Do not use metal objects such as screws and rivets near the antenna, which might affect the antenna efficiency.
• Try to increase the distance from the top shell to the antenna to minimize the impact on antenna performance.
• Try to increase the distance from the upper and bottom shells to the antenna to minimize the impact on antenna performance.
• Keep the module away from speakers, power switches, cameras, HDMI, USB, and other high-speed signals to avoid interference.
• Avoid metal shielding near the antenna. If co-channel interference occurs, you must evaluate the impact on the antenna performance and ensure isolation from interference.

Antenna placement

• Horizontal placement
  We recommend that you place the module at the edge of the backplane with the antenna facing outward, and flush the module’s GND terminal with the backplane’s GND terminal. Both terminals are fully connected.
• Embedded placement
  Embed the module into the backplane through a slot that is flushed with or deeper than the module’s GND terminal. The side of the slot must be 15 mm or farther from the module’s board edge. A wider slot can achieve better performance, but is weaker than that of horizontal placement.
• Vertical placement
  Insert the module vertically into the backplane slot with the antenna facing upward. The module’s GND terminal and the backplane’s GND terminal must be fully connected. We recommend that you keep a clearance distance of 15 mm or more around the antenna.

Microphone and speaker

• Take an internal sound-proof measure between the microphone and speaker. Therefore, the speaker sound can be prevented from being directly transmitted to the microphone.
• The distance between the microphone pickup port and the speaker sound outlet must be ≥100 mm. The angle between the microphone pickup direction and the speaker sound projection direction should be ≥90°.
• The microphone is sealed with a silicone cover from a solid surface. This way, prevent direct hard contact between the silicone microphone and the structure, and reduce the casing vibration and sound transmission.

Flash firmware

• The jumper cap needs to be disconnected during flashing and reinserted after flashing is completed.
• To flash firmware to T1-U-HL, you need to connect 3.3V, GND, T1_TX1, and T1_RX1. To flash firmware to GX8006, you need to connect 5V, GND, GX_TX0, and GX_RX0.
• When a reset prompt appears during T1-U-HL flashing, you need to pull down T1_RST or power off and restart. In the case of GX8006, you need to pull down GX_RST and GX_BOOT.

PCB layout

• Ensure power traces are short and wide, with minimal loops, and provide at least two 8 mil (inner diameter) vias or one 12 mil (inner diameter) via for main IC power pins.
• For power traces, use copper pours whenever possible and add sufficient ground vias for heat dissipation. Pay attention to the current-carrying capacity of single traces.
  Trace width reference (1 oz copper, outer layer): 20 mil width corresponds to 1A (without considering temperature rise).
• The power amplifier IC output lines require differential routing, with coupled traces fully ground-guarded. Trace width should be calculated based on peak output current, and routing should be kept as short as possible.
• The module’s audio output signals DACP and DACN must be routed as differential pairs and fully ground-guarded.
• MIC single-ended grounding: The trace must run parallel to AGND, with a recommended trace width of 8 mil or more.
• The 0Ω resistor connecting GND and AGND must be placed close to the GX8006.
• GX8006 DAC outputs a PWM signal. The RC low-pass filter must be placed close to GX8006.

Reference

• Schematic diagram of the AI box
• T1-U-HL design guidelines
• GX8006 datasheet