Wall-Mount Sensor Reference Design

Tip / Sign in to post questions, reply, level up, and achieve exciting badges. Know more

cross mob
Anonymous
Not applicable
RevisionChange DescriptionDate
1.0Initial01/16/15

The Broadcom Wall-Mount reference design is based on the WICED SMART BCM20737 Bluetooth Low Energy transceiver.

Wall Wart Links:

PFD Schematics: Wall-Mount Sensor Reference Design Schematic (PDF)

Cadence Schematics: Wall-Mount Sensor Reference Design Cadence Schematic Files

Gerber Files: Wall-Mount Sensor Reference Design Gerber Files

The intent of this reference design was to:

  1. Connect as many possible IoT Sensors to the Broadcom BCM20737 device - We utilized an I2C Expander device to ensure proper loading.
  2. Introduce new IoT sensors such as a Gas Sensor, UV Sensor, Ambient Light Sensor and PIR Motion Sensor (5V with USB Plugged into Wall Wart.
  3. Introduced a FET Transistor controlled by P2 GPIO in order to switch off ALL Sensors to save battery power.
  4. Provide a AC Pluggable device (Use USB Connector to Wall Wart device) eliminating the need for a battery pack
  5. If a Wall Wart power was not available, we added 2 CR2 Batteries to the back of the unit to supply power to ALL of the sensors except for the PIR Motion Sensor and you can switch between Wall and Battery powered.
  6. Two LARGE LED's, Red and Green, visible from a distance.
  7. And a custom I2C Connection pads for proprietary use
  8. A DC_DC Converter was added to reduce the Voltage from 3.3 to 2.0V for Power savings.

The Wall-Mount hardware provides the following features:

  • 4 Connection pads (UP_TX, UP_RX, VDDIO and GND) to enable programming of the device
  • SW1: To control BCM_SDA Signal
  • SW2: Push button to reset the BCM20737 device
  • SW3: Button to stop the BCM20737 BLE Radio from Transmitting
  • SW4: Switch from Battery to Wall Wart Power
    • The procedure to recover the EEPROM is as follows:
      • Power off the device
      • Hold down SW3
      • Power on the device
      • Release SW3
      • Proceed to program the new firmware into the device

Here are a few pictures of the Wall-Mount Sensor

Front of the Wall Wart:

pastedImage_1.png

Back of the Wall Wart:

pastedImage_2.png

Thanks

JT

0 Likes
0 Replies