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Formal Tag4 Documentation:
Hardware User Guide (SDK 2.x and TAG4 Board)
WICED Smart Quick Start Guide (SDK 2.x and TAG4 Board)
Tag 4 Quick Hardware Setup:
1. Default switch settings for USB power, Booting SFLASH:
A. SW6 – 2,4 ON, rest OFF
B. SW9 – all ON
C. SW8 – 2, 3, 6, 7, 8 ON, rest OFF
D. SW4 - VUSBs
E. SW5 – VREG
2. On it's very first download, the board requires a recovery:
A. Press-hold BOOT, press-release RESET, release BOOT
B. Edit any make target: replace “download” with “recover UART=COMxx”
C. Use make target. Replace ‘xx’ with your COM port (found in Device Manager)
D. Double click make target to execute build.
NOTE: After your initial recovery, regular “download” can be used.
Tag 4 Traces:
1. Start traces:
A. Download your app
B. Switch SW6 1,2,3 OFF, 4 ON
C. Enable traces on the SDK (WICED Smart IDE > Trace > Start Debug Traces)
D. Press reset button
2. Stop traces:
A. Disable traces on the SDK (WICED Smart IDE > Trace > Stop Debug Traces)
B. Switch SW6 1, 3 OFF, 2, 4 ON
C. Power cycle the Tag 4 board
NOTE: if the board is not power cycled after stopping traces it will not download
NOTE: the SDK traces must be stopped before they will start again.
Tag 4 Power Measurements:
1. Basic Power measurement
A. Remove R29
B. Attach power analyzer to J12
C. Run an app, and start analysis
NOTE: Leads of J12 must be shorted by power analyzer in order to download app
2. Power Optimization:
A. 20737 Chip Specific Optimization:
- Move RD5 and RD6 to A-C position (switches to external DC-DC converter)
B. To reduce peak current of RF TX:
- Remove FB3, disabling FTDI chip (download your app first)
C. To reduce idle current of board:
- Remove R39: disables I2C Expander (no sensors will function)
Tag 4 Boot Sources:
1. Boot EEPROM
A. SW8 – 1,3,5 ON, rest OFF
B. Power cycle
2. Boot SFLASH
A. SW8 – 2,3,6,7,8 ON, rest OFF
B. Power cycle
3. Boot ROM only
A. Press and hold the 'ROM' button on the board
B. Power cycle
C. Release 'ROM' button
NOTE: when switching between boot sources it is often necessary to perform a recovery
Tag 4 I2C:
1. Without any additional action, I2C APIs will only interact with EEPROM.
2. In order to interact with the on-board MEMS sensors and bring out I2C onto J10:
A. The on-board I2C expander must be output enabled by calling:
gpio_configurePin((GPIO_PIN_P8) / 16, (GPIO_PIN_P8) % 16, GPIO_OUTPUT_ENABLE, 1);
B. The I2C voltage rail must be powered by calling:
gpio_configurePin((GPIO_PIN_P2) / 16, (GPIO_PIN_P2) % 16, GPIO_OUTPUT_ENABLE, 0);
Jacob W Torres
Back to main page: Leveraging TAG4 to better understand the WICED Smart Programming Environment