AN3985 datasheet(88/105 Pages) STMICROELECTRONICS

88 / 105 page

Application example

AN3985

88/105

Doc ID 022255 Rev 2

8.1.1

Board initialization

This function configures the STM8L resources needed:

●

Interface bus to communicate with CR95HF device (through SPI or UART bus)

●

Timers

●

LCD

●

I2C

●

GPIO (LED & joystick)

Delay management

The delays are handled by two timers. Timer #4 allows to introduce a delay between two

instructions, whereas timer #2 is used with interrupts to control the execution time of a group

of instructions.

8.1.2

Display initialization

The LCD screen is initialized with the Logo of the STMicroelectronics company and the

CR95HF product name.

8.1.3

Test configuration

This function configures the CR95HF for the application example.

Table 147.

Test config procedure

Step

Action

The first step is to display the interface bus selected to communicate with CR95HF device.

A pulse is sent to CR95HF to wake it up.

An ECHO command is sent while there is no valid answer. If the echo fails, a message is

displayed on the screen and the following procedure is repeated while the echo command

fails:

– Send a pulse to CR95HF

– Echo command

– SPI Reset

At this point, STM8L and CR95HF can communicate which each other.

The internal EEPROM of the STM8L is unlocked.

A protocol select command is issued.

A calibration of the tag detection feature is launched.

A success message is displayed.

AN3985 Datasheet(PDF) 88 Page - STMicroelectronics

AN3985 Datasheet(HTML) 88 Page - STMicroelectronics

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 ...More

Datasheet Download

Link URL