Application description

AN3413

8/18

DocID018933 Rev 2

1.5.2

Bias current record

This operation consists of storing the bias current value of operational amplifier A (see

Figure 2) in the data memory. The bias current value is taken into account for low power

measurements in order to minimize measurement errors. Once recorded, this value is kept

in non-volatile memory for later use. It is recommended to perform this operation when you

start your evaluation in order to obtain the best precision.

This mode is only accessible at application power-up by executing the following steps in the

order below:

1.

Switch OFF STM32L1xx DISCOVERY

2.

3.

Keep USER push-button pressed while powering ON the STM32L1xx DISCOVERY

4.

At power on, a scrolling message “Bias Current” is displayed

5.

Release the USER push-button; the bias current value is displayed and immediately

stored in non-volatile memory

Once this operation completed, replace JP1 in ON position so that the measurement

1.5.3

Manufacturing test

You can access this mode while Demo mode is running, by pressing the USER push-button

for more than 3 seconds and by releasing it. This allows you to verify that the hardware

modules needed by the STM32L1xx DISCOVERY for this example are working properly.

and upper limits. For each test function, the application displays “OK” and the measured

values when available. If all checks are successfully completed, then the message “TEST

OK” is continuously displayed. If one of the tests fails, then the application alerts the user by

continuously displaying the test name followed by “NO OK”.

To exit this manufacturing test, press the RESET button.

Note:

Generally, if the manufacturing test is not successful, first check that JP1 is placed in the ON

position and that all solder bridges are in default position. If errors are found in the Low

Low power run / Low power sleep

STOP / STOP without LCD

STANDBY mode

Table 1. Bars and LCD display linked to functions (continued)

Function

Bars