Operation
2. Connect a 21-V supply across 21 V (J3-1) and BAT- (J2-2)
To change the EEPROM values, simply click on the value to be changed, enter the new value, and press
enter.
The EEPROM values can be stored in a file on the PC by using the
File|Save Gas Gauge Flash
Constants
command from the pulldown menu. Similarly, a saved file can be loaded by using the
File|Open Gas Gauge Flash Constants
command. Once the file is called up, the Write all EEPROM
button can be used to write all the EEPROM values at once.
NOTE:
Changing EEPROM data affects critical aspects of the bq27x10 operation. Review the
bq27x10 data sheet to determine how to develop new data for the EEPROM based on your
application. It is recommended to first save the default EEPROM data as a file before
changing the data. In this way, the default data programming can easily be restored.
The bq27x10 automatically uses the new EEPROM in its calculations once programmed.
8.2.3
Resetting the bq27x10
The bq27x10 can be reset at anytime by using the
Options|Special Options|Reset bq27x10
from the
pulldown menu. When reset, the bq27x10 reinitializes all RAM registers.
8.3
The Registers Screen
In the Registers screen, all the bq27x10's RAM registers are displayed.
8.3.1
Options Menu
This menu allows the user to select among different options. These options include whether to enable
scan of registers, select the file logging time rate, select the type of communication protocol (HDQ or I2C),
or select the type of communication interface (EV2300 or EV2200).
8.3.2
Commands Menu
With the bq27x10, several commands are performed by setting the appropriate bit in the MODE register
and then writing 0xA9 or 0x56 into address 0x00. With the Commands menu of the EVSW, the user may
perform the commands automatically. Among the selections are:
•
WRTNAC - If a user wants to write the NAC register to a specific value, the user writes that value to
the AT RATE register and then selects WRTNAC from the Commands menu.
•
DONE - The user selects DONE when charging is complete, and the monitor is not able to detect taper
current. It forces an update of internal registers to represent a full battery condition.
•
PRST - This command causes a reset except that NAC, LMD, and the CI bit in FLAGS register are not
restored to initial values. This command is intended for manufacturing use.
•
FRST - This command re-initializes all RAM registers. This command is intended for manufacturing
use.
•
SHIP - Once this command is given, the bq27x10EVM enters ship mode if the HDQ has been pulled
low for at least 18 seconds. A full reset is forced when the part leaves ship mode.
•
WNACCI - It is identical to the WRTNAC command, but the CI bit in FLAGS is also cleared.
•
WRTCYC - It is used to transfer data from the AR registers to CYCT.
•
WRTLMD - It is used to transfer data from the AR registers to LMD.
8.3.3
GPIO Menu
This menu selects the function of the GPIO pin as an output or input. If selected as an output, the open-
drain output can be set to on or off.
13
SLUU259A – October 2006 – Revised October 2013
bq27x10EVM Single-Cell Battery Fuel Gauge Evaluation Module
Copyright © 2006–2013, Texas Instruments Incorporated
