ST AN3954 Installation and operating instructions

January 2017 Doc ID022016 Rev 4 1/47
1
AN3954
Application note
Developing your own Visual Basic or C/C++ application
on a CR95HF demonstration board
Introduction
This application note explains how to develop an application using either Visual Basic or
C/C++ language to drive a CR95HF demonstration board from a host computer.
CR95HF demonstration board is a kit that allows the user to evaluate the performance of
STMicroelectronics CR95HF, a 13.56 MHz multiprotocol contactless transceiver. It includes
a ready-to-use board to interface with the CR95HF host PC demonstration software through
an USB interface. The CR95HF demonstration board is included in the M24LR-
DISCOVERY kit (see Figure 1).
The board is powered through the USB port, and no external power supply is required. It is
made up of a CR95HF, a 48 mm x 34 mm, 13.56 MHz inductive etched antenna and its
associated tuning components. The CR95HF communicates with the STM32F103CB 32-bit
core microcontroller via the SPI bus.
A dynamic link library (DLL) file is used by the host computer to manage several functions
and to communicate with both the STM32 MCU and the CR95HF
Source code examples described in this application note and additional demonstrations can
be found in the package STSW-95HF002, which can be downloaded from www.st.com.
Some basic examples are available in C/C++, additional examples are available in a Visual
Basic 6 project, among them NDEF message management on Type 4A and Type 5,
ST25DV user interface and FTM demonstrations. DLL file is also available in this package.
Figure 1. CR95HF demonstration board embedded in the M24LR-Discovery kit
For more information, refer to the following documents, available on www.st.com:
•M24LR-DISCOVERY databrief
•CR95HF datasheet
•User manual UM1084 “CR95HF development software”
•STSW-95HF002 source code example
www.st.com

Contents AN3954
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Contents
1 Getting started . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
1.1 Connecting the board to the computer . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
1.2 Using the DLL system file . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
1.2.1 Overview of DLL functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
2 Description of functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
2.1 Functions to check DLL installation and USB connection . . . . . . . . . . . . . 8
2.1.1 CR95HFDll_GetDLLrev . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
2.1.2 CR95HFDLL_USBconnect . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
2.1.3 CR95HFDLL_USBhandlecheck . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
2.2 Functions to communicate with the STM32 MCU . . . . . . . . . . . . . . . . . . 12
2.2.1 CR95HFDll_Echo . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
2.2.2 CR95HFDLL_getMCUrev . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
2.2.3 CR95HFDLL_getHardwareVersion . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
2.2.4 CR95HFDLL_getInterfacePinState . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
2.3 Functions to communicate with the CR95HF IC . . . . . . . . . . . . . . . . . . . 20
2.3.1 CR95HFDll_Idn . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
2.3.2 CR95HFDll_Select . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
2.3.3 CR95HFDll_STCmd . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
2.3.4 CR95HFDll_FieldOff . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
2.3.5 CR95HFDll_ResetSPI . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
2.3.6 CR95HFDll_SendIRQPulse . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
2.3.7 CR95HFDll_Polling_Reading . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
2.3.8 CR95HFDll_SendNSSPulse . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
2.4 Functions to communicate with an RF tag . . . . . . . . . . . . . . . . . . . . . . . . 40
2.4.1 CR95HFDll_SendReceive . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
2.4.2 SendReceive Request and Response maximum data size . . . . . . . . . . 43
Appendix A Error codes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46

Doc ID022016 Rev 4 3/47
AN3954 List of tables
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List of tables
Table 1. List of error codes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
Table 2. Document revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46

List of figures AN3954
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List of figures
Figure 1. CR95HF demonstration board embedded in the M24LR-Discovery kit . . . . . . . . . . . . . . . . 1
Figure 2. Typical application block diagram. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Figure 3. Function CR95HFDLL_USBconnect . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Figure 4. Driving the MCU on the CR95HF demonstration board from the PC . . . . . . . . . . . . . . . . . . 6
Figure 5. Driving the CR95HF from the PC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Figure 6. Sending frames directly to the tag . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

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AN3954 Getting started
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1 Getting started
This application note and the source code example have been written to help users to easily
develop their applications. This document note contains function descriptions and some use
cases.
To improve the use of CR95HF demonstration board and the communication with tags, it is
recommended to download and use the CR95HF development software (STSW-95HF001)
available on www.st.com. This software (and not this application note) can be used as a
reference to improve and test the CR95HF demonstration board functions and the
communication with tags, in various RF protocols.
1.1 Connecting the board to the computer
As shown in Figure 2, the CR95HF demonstration board is connected to the host computer
through its USB port, no particular driver is needed. The HID USB driver (already included in
all Windows operating systems) is used for communication.
Through the USB port of the computer, the user can drive the board, communicate with the
STM32 MCU, manage the CR95HF IC and send requests to an RF tag.
Figure 2. Typical application block diagram
1.2 Using the DLL system file
A DLL file (CR95HF.dll) is provided to drive the CR95HF demonstration board from your
computer, copy this file to the system folder of your computer (C:/Windows/system32/).
This DLL contains several functions to enable communication with the board.
Using this DLL, the host computer is able to manage several functions and communicate
with the STM32 MCU and the CR95HF IC.
1.2.1 Overview of DLL functions
The CR95HFDll_GetDLLrev function reads the revision number of the DLL file. If the DLL
file is not correctly installed in the system folder of the host computer, this function returns
an error message (see Figure 3).
The CR95HFDLL_USBconnect function (available from DLL revision 0.5 and higher) is
required to connect the CR95HF demonstration board to the host computer and
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Getting started AN3954
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communicate with it. The computer first checks if a CR95HF demonstration board is
connected to the USB port. If so, it assigns a USB handle to the board (see Figure 3).
The CR95HFDLL_USBhandlecheck function can be used to verify if the CR95HF
demonstration board is connected to the USB port of the computer. It is available from DLL
revision 0.6 and higher. This function sends a request to the CR95HF demonstration board
and waits for an acknowledge. An error code is sent if the communication with the board has
been lost. In this case, the CR95HFDLL_USBconnect can be used to reconnect the board
to the host computer.
Figure 3. Function CR95HFDLL_USBconnect
A set of functions are available to drive the STM32 MCU (see Figure 4):
•CR95HFDll_Echo: verifies that the CR95HF demonstration board is connected to the
USB port of the computer.
•CR95HFDLL_getMCUrev: reads the firmware revision of the STM32 MCU.
•CR95HFDLL_getHardwareVersion: reads the hardware version of the boards
(available on latest MCU revision boards / introduced from dll revision 0.9).
•CR95HFDLL_getInterfacePinState: verifies the communication path between the
STM32 MCU and the CR95HF IC (either SPI or UART).
Figure 4. Driving the MCU on the CR95HF demonstration board from the PC
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AN3954 Getting started
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Other functions can be used to send instructions to the CR95HF IC (see Figure 5):
•CR95HFDll_Idn: gets the IDN of the CR95HF IC.
•CR95HFDll_Select: configures the required RF protocol for the CR95HF IC (IS0
15693, ISO 14443B …) and starts the RF field on the antenna.
•CR95HFDll_STCmd: sends commands to the CR95HF IC (refer to datasheet for a list
of possible commands).
•CR95HFDll_FieldOff: stops the RF field of the CR95HF IC.
•CR95HFDll_ResetSPI: resets the SPI interface of the CR95HF IC.
•CR95HFDll_SendIRQPulse: sends an interruption pulse on the IRQ pin of the CR95HF
IC to wake it up. This interrupt function can be used when the communication between
the STM32 MCU and the CR95HF demonstration board is performed in SPI mode.
•CR95HFDll_SendNSSPulse: sends an interrupt pulse to the NSS pin of the CR95HF
IC to wake it up. This interrupt function can be used when the communication between
the STM32 MCU and the CR95HF demonstration board is performed in UART mode.
•CR95HFDll_Polling_Reading: launches a polling sequence and reads the CR95HF
answer buffer to retrieve the answer when it is not available in the FIFO answer buffer
(e.g. after an IDLE command)
Figure 5. Driving the CR95HF from the PC
Finally, the CR95HFDll_SendReceive function sends an RF frame to any tag present in the
RF field and receives its answer according to the RF protocol previously defined using the
Select command (see Figure 6).
Figure 6. Sending frames directly to the tag
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Description of functions AN3954
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2 Description of functions
This section describes the various functions required to evaluate the CR95HF
demonstration board.
2.1 Functions to check DLL installation and USB connection
2.1.1 CR95HFDll_GetDLLrev
This function detects if the CR95HF.dll file has been installed in the system folder of the host
PC system, reads its header and sends back its revision number.
This is used by software to ensure that the DLL is correctly installed and that it is up to date.
If no DLL file is found, it returns an error message.
Visual Basic language
Declaration: Public Declare Function CR95HFDll_GetDLLrev Lib
"CR95HF.dll" (ByVal mystring As String) As Long
Prototype: Dim lngStatus As Long
Dim strAnswer As String * 256
lngStatus = CR95HFDll_GetDLLrev(strAnswer)
Input parameter:None
Output parameter: strAnswer: Revision of the DLL installed on your PC system.
Answer example: "0.4"
Returned value: lngStatus: 0
Source code example
Private Sub cmdGetDllRev_Click()
Dim strAnswer As String * 256
Dim lngStatus As Long
lngStatus = CR95HFDll_GetDLLrev(strAnswer)
If (lngStatus = 0) Then
txtDllRev.Text = strAnswer
Else txtDllRev.Text = "Error = no Dll found"
End If
End Sub

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AN3954 Description of functions
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C/C++ language
Declaration: __declspec(dllimport) int __stdcall
CR95HFDll_GetDLLrev(char* stringreply);
Prototype:int iresult;
char strAnswer[50]="";
iresult = CR95HFDll_GetDLLrev(strAnswer);
Input parameter: None
Output parameter: strAnswer: Revision of the DLL installed on your PC system.
Answer example: "0.4"
Returned value: lresult: 0
Source code example
int Get_Dll_rev (void)
{char strAnswer[50]="";
int iresult;
char entry3;
printf("\n\n\n\n");
iresult = CR95HFDll_GetDLLrev(strAnswer);
printf("\nGet Dll revision using CR95HFDll_GetDLLrev
function:\n");
printf("\n --> request : CR95HFDll_GetDLLrev(strAnswer)");
printf("\n <-- answer : ");
if (iresult == 0)
printf("%s = DLL version\n\n\r", strAnswer);
else printf("%s = Error : no communication with MCU\n\n\r",
strAnswer);
printf("\n\n\n\n");
printf("\npress any key to continue");
printf("\n");
scanf("%s", &entry3);
return iresult;
}

Description of functions AN3954
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2.1.2 CR95HFDLL_USBconnect
This function can be used to connect the CR95HF demonstration board to the computer
USB port. The computer then assigns a USB handle to the board.
Visual Basic language
Declaration: Public Declare Function CR95HFDLL_USBconnect
Lib"CR95HF.dll" () As Long
Prototype:Dim lngStatus As Long
lngStatus = CR95HFDLL_USBconnect()
Input parameter: None
Output parameter: None
Returned value: lngStatus:
0: the CR95HF demonstration board is connected
and ready to be used
1: the CR95HF demonstration board is not connected
Source code example
Private Sub cmdUSBconnect_Click()
Dim lngStatus As Long
lngStatus = CR95HFDLL_USBconnect()
If (lngStatus = 0) Then
txtUSBconnectAnswer.Text="CR95HF demonstration board connected
and ready to be used"
Else txtUSBconnectAnswer.Text = "CR95HF demonstration board not
connected"
End If
End Sub
C/C++ language
Declaration: __declspec(dllexport) int __stdcall
CR95HFDLL_USBconnect(void);
Prototype:int iresult;
iresult= CR95HFDLL_USBconnect ();
Input parameter: None
Output parameter: None
Returned value: iresult:
0: the CR95HF demonstration board is connected and
ready to be used
1: the CR95HF demonstration board is not connected
Source code example
int DEMO_CR95HF_A_USBconnect (void)
{int iresult;
char entry3;
printf("\n\n\n\n");