USB Audio Descriptor - audio
I'm trying to implement a PIC32 MCU as a Audio device, using USB audio class 1.
I have implementet this project: PIC32 USB Digital Audio Accesory Board Demos.zip
and it works fine, but now i want to cut away some of the Audio Control Interface, so i'm having a more simple Audio function:
The device seems to get enumerated properly acording to the status LED's on the board, and it appears in Device Manager's list of audio devices, but it has a small yellow exclamation mark.. And when i plug in the device, windows tells me: "Device driver software was not succesfully installed"
Anybody has a clue?
USB descriptors, block of code:
ROM BYTE configDescriptor1[] ={
//CD
0x09, // Size : 9 Bytes
0x02, // Configuration Descriptor (0x02)
//0xE4, // Total length in bytes of data returned Includes the combined length of all descriptors (configuration, interface, endpoint, and class- or vendor-specific) returned for this configuration.
0xB4, // Ved simpel Audio Function
0x00, // 2. Byte af Total Length // 228
0x03, // Number of Interfaces: 3
0x01, // bConfigurationValue, Value to use as an argument to select this configuration
0x00, // iConfiguration, Index of String Descriptor describing this configuration
_DEFAULT | _SELF, // bmAttributes, 0b01100000 -> D6: Self-powered, D7: Reserved (set to one)
0xFA, // Maximum Power : 250 * 2mA = 0,5A
//ID - INTERFACE 0 Control
0x09, // Size : 9 Bytes
0x04, // Interface Descriptor (0x04)
0x00, // Number of Interface: Interface nr 0
0x00, // Value used to select alternative setting
0x00, // Number of Endpoints used for this interface, 0
0x01, // Class Code (Assigned by USB Org), AUDIO
0x01, // Subclass Code (Assigned by USB Org), AUDIOCONTROL
0x00, // Protocol Code (Assigned by USB Org)
0x00, // Index of String Descriptor Describing this interface
//ACID - HEADER
0x0A, // Size : 10 Bytes
0x24, // CS_INTERFACE Descriptor Type
0x01, // HEADER descriptor subtype
0x00,0x01, // Audio Device compliant to the USB Audio specification version 1.00
//0x64,0x00, // 100 bytes - Total number of bytes returned for the class-specific AudioControl interface descriptor. // Includes the combined length of this descriptor header and all Unit and Terminal descriptors.
0x00,0x34, // wTotalLength
0x02, // bInCollection -> Number of streaming interfaces = 2
0x01, // baInterfaceNr(1) -> 0x01 = 1 -> Interface number of the first AudioStreaming interface in the Collection
0x02, // baInterfaceNr(2) -> 0x02 = 2 -> Interface number of the second AudioStreaming interface in the Collection
//ACID - INPUT_TERMINAL ID = 1
0x0C, // size : 12 bytes
0x24, // CS_INTERFACE Descriptor Type
0x02, // INPUT_TERMINAL - Descriptor subtype = 2
0x01, // ID of this Input Terminal. // Constant uniquely identifying the Terminal within the audio function.
0x01,0x01, // wTerminalType -> 0x0101 = USB streamming
0x00, // bAssocTerminal -> 0x00 = No association.
//0x03, // bAssocTerminal -> 0x03 = Associated with OUTPUT TERMINAL 3
0x02, // bNrChannels -> 0x02 two channel.
0x03,0x00, // wChannelConfig -> 0x0003 = stereo, Right / Left // se Audio Devices Dok side 34
//0x00,0x00, // wChannelConfig -> 0x0000 = mono ?
0x00, // iChannelNames -> 0x00 = Unused.
0x00, // iTerminal -> 0x00 = Unused.
//ACID - INPUT_TERMINAL ID = 4
0x0C, // size : 12 bytes
0x24, // CS_INTERFACE Descriptor Type
0x02, // INPUT_TERMINAL - Descriptor subtype
0x04, // bTerminalID -> ID of this Input Terminal = 4
0x01,0x02, // wTerminalType -> 0x0201 = Microphone
0x00, // bAssocTerminal -> 0x00 = No association.
//0x06, // bAssocTerminal -> 0x06 = Associated with OUTPUT TERMINAL 6
0x01, // bNrChannels -> 0x01 one channel.
0x01,0x00, // wChannelConfig -> Left Front <- original fra ex.
//0x00,0x00, // wChannelConfig -> 0x0000 = mono
0x00, // iChannelNames -> 0x00 = Unused.
0x00, // iTerminal -> 0x00 = Unused.
//ACID - OUTPUT_TERMINAL ID = 3
0x09, // size : 9 Bytes
0x24, // CS_INTERFACE Descriptor Type
0x03, // OUTPUT_TERMINAL - Descriptor subtype
0x03, // bTerminalID -> ID of this Output Terminal = 3
0x01,0x03, // wTerminalType -> 0x0301 = Speaker
0x00, // bAssocTerminal -> 0x00 = Unused
//0x01, // bAssocTerminal -> 0x01 = Associated with INPUT TERMINAL 1
//0x02, // bSourceID -> 0x02 = From FEATURE_UNIT ID 2 = USB stream
0x01, // bSourceID -> 0x01 = From Input Terminal ID 1
0x00, // iTerminal -> 0x00 = Unused.
//ACID - OUTPUT_TERMINAL ID = 6
0x09, // Size : 9 Bytes
0x24, // CS_INTERFACE Descriptor Type
0x03, // OUTPUT_TERMINAL - Descriptor subtype
0x06, // bTerminalID -> ID of this Output Terminal = 6
0x01,0x01, // wTerminalType -> 0x0101 = USB streaming
0x00, // bAssocTerminal -> 0x00 = Unused
//0x04, // bAssocTerminal -> 0x04 = Associated with INPUT TERMINAL 4
//0x09, // bSourceID -> 0x09 = From Selector Unit ID 9
0x04, // bSourceID -> 0x04 = From INPUT_TERMINAL ID 4
0x00, // iTerminal -> 0x00 = Unused.
/* ##### INTERFACE 1 - OUT ##### */
//ID - INTERFACE 1/0 Stream
0x09, // Size : 9 Bytes
0x04, // Interface Descriptor (0x04)
0x01, // bInterfaceNumber -> 0x01 Interface ID = 1 Number of this interface. Zero-based value identifying the index in the array of concurrent interfaces supported by this configuration.
0x00, // bAlternateSetting -> 0x00 = index of this interface's alternate setting
0x00, // bNumEndpoints -> 0x00 = 0 Endpoints to this interface
0x01, // bInterfaceClass -> 0x01 = Audio Interface
0x02, // bInterfaceSubclass -> 0x02 = AUDIO_STREAMING
0x00, // bInterfaceProtocol -> 0x00 = Unused
0x00, // iInterface -> 0x00 = Unused
//ID - INTERFACE 1/1 Stream
0x09, // Size : 9 Bytes
0x04, // Interface Descriptor (0x04)
0x01, // bInterfaceNumber -> 0x01 Interface ID = 1
0x01, // bAlternateSetting -> 0x01 = index of this interface's alternate setting
0x01, // bNumEndpoints -> 0x01 = 1 Endpoints to this interface
0x01, // bInterfaceClass -> 0x01 = Audio Interface
0x02, // bInterfaceSubclass -> 0x02 = AUDIO_STREAMING
0x00, // bInterfaceProtocol -> 0x00 = Unused
0x00, // iInterface -> 0x00 = Unused
//ASID - GENERAL
0x07, // Size : 7 Bytes
0x24, // CS_INTERFACE Descriptor Type
0x01, // bDescriptorSubtype -> 0x01 = GENERAL subtype
0x01, // bTerminalLink -> 0x01 = The Terminal ID of the Terminal to which the endpoint of this interface is connected.
0x01, // bDelay -> 0x01 = Delay (delta) introduced by the data path (see Section 3.4, ?Inter Channel Synchronization? - in Audio Devices). Expressed in number of frames.
0x01,0x00, // wFormatTag -> 0x0001 = PCM
//ASID - FORMAT_TYPE
0x0E, // Size : 14 Bytes
0x24, // CS_INTERFACE Descriptor Type
0x02, // bDescriptorSubtype -> 0x02 = FORMAT_TYPE
0x01, // bFormatType -> 0x01 = FORMAT_TYPE_I -> ref: A.1.1 Audio Data Format Type I Codes -> Audio Data Format Dok
0x02, // bNrChannels -> 0x02 = Two channels
0x02, // bSubFrameSize -> 0x02 = 2 bytes pr audio subframe
0x10, // bBitResolution -> 0x10 = 16 bit pr sample
0x02, // bSamFreqType -> 0x02 = 2 sample frequencies supported
0x80,0xBB,0x00, // tSamFreq -> 0xBB80 = 48000 Hz
0x00,0x7D,0x00, // tSamFreq -> 0x7D00 = 32000 Hz
//0x44,0xAC,0x00,
//ED - ENDPOINT OUT
0x09, // Size : 9 Bytes
0x05, // 0x05 -> ENDPOINT Descriptor Type
0x01, // bEndpointAddress -> 0x01 = adress 1, OUT, -> ref 9.6.6 Endpoint -> usb_20 Dok
0x09, // bmAttributes -> 0b00001001 -> Bits 0-1 = 01 = Isochronous , Bits 2-3 = 10 = Adaptive
AUDIO_MAX_SAMPLES * sizeof ( AUDIO_PLAY_SAMPLE ), 0x00, // wMaxPacketSize -> 48 * 4 = 0x0030 :Maximum packet size this endpoint is capable of sending or receiving when this configuration is selected.
0x01, // bInterval -> 0x01 = 1 millisecond
0x00, // ?? not described -> 0x00 = Unused
0x00, // ?? not described -> 0x00 = Unused
//CSED - CS ENDPOINT
0x07, // Size : 7 Bytes
0x25, // CS_ENDPOINT
0x01, // bDescriptorSubtype -> 0x01 = GENERAL
0x01, // bmAttributes -> 0b00000001 = Bit 1 = 1 => Sample Freq Control is supported by this endpoint
0x00, // bLockDelayUnits -> 0x00 = Indicates the units used for the wLockDelay field: 0 = Undefined
0x00,0x00, // the time it takes this endpoint to reliably lock its internal clock recovery circuitry.
/* ##### INTERFACE 2 - IN ##### */
//ID - INTERFACE 2/0 Stream
0x09, // Size : 9 Bytes
0x04, // Interface Descriptor (0x04)
0x02, // bInterfaceNumber -> 0x02 Interface ID = 2
0x00, // bAlternateSetting -> 0x00 = Value used to select this alternate setting for the interface identified in the prior field
0x00, // bNumEndpoints -> 0x00 = 0 -> Number of endpoints used by this interface
0x01, // bInterfaceClass -> 0x01 = 1 = AUDIO
0x02, // bInterfaceSubClass -> 0x02 = AUDIO_STREAMING
0x00, // bInterfaceProtocol -> 0x00 = Unused
0x00, // iInterface -> 0x00 = Unused -> Index of string descriptor.
//ID - INTERFACE 2/1 Stream
0x09, // Size : 9 Bytes
0x04, // Interface Descriptor (0x04)
0x02, // bInterfaceNumber -> 0x02 Interface ID = 2
0x01, // bAlternateSetting -> 0x01 = Value used to select this alternate setting for the interface identified in the prior field
0x01, // bNumEndpoints -> 0x01 = 1 -> Number of endpoints used by this interface
0x01, // bInterfaceClass -> 0x01 = 1 = AUDIO
0x02, // bInterfaceSubClass -> 0x02 = AUDIO_STREAMING
0x00, // bInterfaceProtocol -> 0x00 = Unused
0x00, // iInterface -> 0x00 = Unused -> Index of string descriptor.
//ASID - GENERAL
0x07, // Size : 7 Bytes
0x24, // CS_INTERFACE Descriptor Type
0x01, // GENERAL Descriptor
0x06, // bTerminalLink -> 0x06 = The Terminal ID of the Terminal to which the endpoint of this interface is connected = 6
0x01, // bDelay -> 0x01 = Delay (delta) introduced by the data path (see Section 3.4, ?Inter Channel Synchronization? - in Audio Devices). Expressed in number of frames.
0x01,0x00, // wFormatTag -> 0x0001 = PCM
//ASID - FORMAT_TYPE
0x0E, // Size : 14 Bytes
0x24, // CS_INTERFACE Descriptor Type
0x02, // bDescriptorSubtype -> 0x02 = FORMAT_TYPE
0x01, // bFormatType -> 0x01 = FORMAT_TYPE_I -> ref: A.1.1 Audio Data Format Type I Codes -> Audio Data Format Dok
0x02, // bNrChannels -> 0x02 = Two channels
0x02, // bSubFrameSize -> 0x02 = 2 bytes pr audio subframe
//0x03, // bSubFrameSize -> 0x03 = 3 bytes pr audio subframe
0x10, // bBitResolution -> 0x10 = 16 bit pr sample
//0x18, // bBitResolution -> 0x18 = 24 bit pr sample
0x02, // bSamFreqType -> 0x02 = 2 sample frequencies supported
0x80,0xBB,0x00, // tSamFreq -> 0xBB80 = 48000 Hz
0x00,0x7D,0x00, // tSamFreq -> 0x7D00 = 32000 Hz
//0x44,0xAC,0x00, // 44100 Hz
//ED - ENDPOINT IN
0x09, // Size : 9 Bytes
0x05, // 0x05 -> ENDPOINT Descriptor Type
0x82, // bEndpointAddress -> 0x82 = adress 2, IN, -> ref 9.6.6 Endpoint -> usb_20 Dok
0x05, // bmAttributes -> 0b00000101 -> Bits 0-1 = 01 = Isochronous , Bits 2-3 = 01 = Asynchronous
AUDIO_MAX_SAMPLES * (sizeof ( AUDIO_PLAY_SAMPLE )), 0x00, // wMaxPacketSize -> 48 * 4 = 0x0030 :Maximum packet size this endpoint is capable of sending or receiving when this configuration is selected.
//0x20,0x01,
0x01, // bInterval -> 0x01 = 1 millisecond
0x00, // bRefresh -> ??
0x00, // bSynchAddress -> ??
//CSED - CS ENDPOINT
0x07, // Size : 7 Bytes
0x25, // bDescriptorType -> 0x25 = CS_ENDPOINT
0x01, // bDescriptorSubtype -> 0x01 = GENERAL
0x01, // bmAttributes -> 0b00000001 = Bit 1 = 1 => Sample Freq Control is supported by this endpoint
0x00, // bLockDelayUnits -> 0x00 = Indicates the units used for the wLockDelay field: 0 = Undefined
0x00,0x00, // the time it takes this endpoint to reliably lock its internal clock recovery circuitry
};
So i solved my question!
As chris commented, i had to implement some sort of control, into the control interface. First i added two Feature units, as seen on the picture. I implemented made then support no controls, by setting:
bmaControls(1) = 0x00 // No control support
This cause windows to install the device driver properly, but i still couldn't see the microphone in "Recording Devices" in the sound settings.
The i implemented Mute control, by changing the control parameter to:
bmaControls(1) = 0x01 // Mute support
Now i could see the microphone in the settings, but the gain was different from what i expected. Then i changed the controls to Volume control, by changing the control parameter to:
bmaControls(1) = 0x02 // Volume support
This made the microphone work as i expected...
Thanks Chris!
Related
Casting to 8 bytes variable takes only 4 bytes
I have structure that contains two fields:
struct ggg {
unsigned long long int a;
unsigned int b;
};
Field a should be 8 bytes long, while b one is 4 bytes long.
Trying to cast it to array of bytes:
unsigned char c[8 + 4] = { 0x01, 0x00, 0x00, 0x00, 0x02, 0x00, 0x00, 0x00,
0x03, 0x00, 0x00, 0x00, };
ggg* g = (ggg *)c ;
char tt[1024];
sprintf(tt, "a=%d b=%d ", g->a, g->b);
Got result in tt string :
a=1 b=2
Looks like while casting a takes only 4 bytes instead of 8. Why?
The problem is not casting but your sprintf format specifiers. You are using %d which means signed int, which typically is 4 bytes. Try changing the format string to "a=%llu b=%u" and you are more likely to get the expected output.
BPF filter fails
Can anyone suggest why this (classic) BPF program sometimes lets non-DHCP-response packets through:
# Load the Ethertype field
BPF_LD | BPF_H | BPF_ABS 12
# And reject the packet if it's not 0x0800 (IPv4)
BPF_JMP | BPF_JEQ | BPF_K 0x0800 0 8
# Load the IP protocol field
BPF_LD | BPF_B | BPF_ABS 23
# And reject the packet if it's not 17 (UDP)
BPF_JMP | BPF_JEQ | BPF_K 17 0 6
# Check that the packet has not been fragmented
BPF_LD | BPF_H | BPF_ABS 20
BPF_JMP | BPF_JSET | BPF_K 0x1fff 4 0
# Load the IP header length field
BPF_LDX | BPF_B | BPF_MSH 14
# And load that offset + 16 to get the UDP destination port
BPF_LD | BPF_IND | BPF_H 16
# And reject the packet if the destination port is not 68
BPF_JMP | BPF_JEQ | BPF_K 68 0 1
# Accept the frame
BPF_RET | BPF_K 1500
# Reject the frame
BPF_RET | BPF_K 0
It doesn't let every frame through, but under heavy network load it fails quite often. I'm testing it with this Python 3 program:
import ctypes
import struct
import socket
ETH_P_ALL = 0x0003
SO_ATTACH_FILTER = 26
SO_ATTACH_BPF = 50
filters = [
0x28, 0x00, 0x00, 0x00, 0x0c, 0x00, 0x00, 0x00, 0x15, 0x00, 0x00, 0x08, 0x00, 0x08, 0x00, 0x00,
0x30, 0x00, 0x00, 0x00, 0x17, 0x00, 0x00, 0x00, 0x15, 0x00, 0x00, 0x06, 0x11, 0x00, 0x00, 0x00,
0x28, 0x00, 0x00, 0x00, 0x14, 0x00, 0x00, 0x00, 0x45, 0x00, 0x04, 0x00, 0xff, 0x1f, 0x00, 0x00,
0xb1, 0x00, 0x00, 0x00, 0x0e, 0x00, 0x00, 0x00, 0x48, 0x00, 0x00, 0x00, 0x10, 0x00, 0x00, 0x00,
0x15, 0x00, 0x00, 0x01, 0x44, 0x00, 0x00, 0x00, 0x06, 0x00, 0x00, 0x00, 0xdc, 0x05, 0x00, 0x00,
0x06, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
]
filters = bytes(filters)
b = ctypes.create_string_buffer(filters)
mem_addr_of_filters = ctypes.addressof(b)
pf = struct.pack("HL", 11, mem_addr_of_filters)
pf = bytes(pf)
def main():
sock = socket.socket(socket.AF_PACKET, socket.SOCK_RAW, socket.htons(ETH_P_ALL))
sock.bind(("eth0", ETH_P_ALL))
sock.setsockopt(socket.SOL_SOCKET, SO_ATTACH_FILTER, pf)
# sock.send(req)
sock.settimeout(1)
try:
data = sock.recv(1500)
if data[35] == 0x43:
return
print('Packet got through: 0x{:02x} 0x{:02x}, 0x{:02x}, 0x{:02x}'.format(data[12], data[13], data
except:
print('Timeout')
return
sock.close()
for ii in range(1000):
main()
If I do this while SCPing a big core file to the host running that script, it doesn't reach the one-second timeout in the large majority of, but not all, cases. Under lighter load failures are much rarer - eg twiddling around on an ssh link while the socket is receiving; sometimes it gets through 1000 iterations without failure.
The host in question is Linux 4.9.0. The kernel has CONFIG_BPF=y.
Edit
For a simpler version of the same question, why does this BPF program let through any packets at all:
BPF_RET | BPF_K 0
Edit 2
The tests above were on an ARM64 machine. I've retested on amd64 / Linux 5.9.0. I still see failures, though not nearly as many.
I got a response on LKML explaining this. The problem is that the filter is applied as the frame arrives on the interface, not as it's passed to userspace with recv(). So under heavy load, frames arrive between the creation of the socket with socket.socket(socket.AF_PACKET, socket.SOCK_RAW, socket.htons(ETH_P_ALL)) and the filter being applied with sock.setsockopt(socket.SOL_SOCKET, SO_ATTACH_FILTER, pf). These frames sit in the queue; once the filter is applied, subsequent arriving packets have the filter applied to them. So once the filter is applied, it's necessary to "drain" any queued frames from the socket before you can rely on the filter.
2x beaglebone black microcontrolers and nrf24l01 connection doesn't work
I'm trying to setup connection between two BBB using nrf24l01. I hope i set up everything properly( but I'm not really sure), I used this tutorial https://electron14.com/?p=404 and this code : RF24/librf24-bbb/librf24, and some self investigation. the result of pingtest is : ./pingtest RF24/examples/pingpair/ ROLE: Ping out - gpio.cpp RF24::begin end fun STATUS = 0x0e RX_DR=0 TX_DS=0 MAX_RT=0 RX_P_NO=7 TX_FULL=0 RX_ADDR_P0-1 = 0xf0f0f0f0e1 0xf0f0f0f0d2 RX_ADDR_P2-5 = 0xc3 0xc4 0xc5 0xc6 TX_ADDR = 0xf0f0f0f0e1 RX_PW_P0-6 = 0x20 0x20 0x00 0x00 0x00 0x00 EN_AA = 0x00 EN_RXADDR = 0x03 RF_CH = 0x4c RF_SETUP = 0x27 CONFIG = 0x0f DYNPD/FEATURE = 0x00 0x00 Data Rate = 250KBPS Model = nRF24L01+ CRC Length = 16 bits PA Power = PA_HIGH Now sending 23...ok...Failed, response timed out. Now sending 1231...ok...Failed, response timed out. Now sending 2441...ok...Failed, response timed out. Now sending 3649...ok...Failed, response timed out. Now sending 4859...ok...Failed, response timed out. Now sending 6071...ok...Failed, response timed out. and from other BBB pongtest ./pongtest RF24/examples/pingpair/ ROLE: Pong back STATUS = 0x0e RX_DR=0 TX_DS=0 MAX_RT=0 RX_P_NO=7 TX_FULL=0 RX_ADDR_P0-1 = 0xf0f0f0f0d2 0xf0f0f0f0e1 RX_ADDR_P2-5 = 0xc3 0xc4 0xc5 0xc6 TX_ADDR = 0xf0f0f0f0d2 RX_PW_P0-6 = 0x20 0x20 0x00 0x00 0x00 0x00 EN_AA = 0x00 EN_RXADDR = 0x03 RF_CH = 0x4c RF_SETUP = 0x27 CONFIG = 0x0f DYNPD/FEATURE = 0x00 0x00 Data Rate = 250KBPS Model = nRF24L01+ CRC Length = 16 bits PA Power = PA_HIGH Can someone help me ?
Based on your data, both devices have a status register value of 0x0e, which is clearing the lsb; that bit sets the direction of the device, either Tx (0) or Rx (1). Based on the status register of each board being cleared, you have both of them setup as transmitters.
ISO 15693: read multiple security blocks
I am trying to modify an existing SCardTransmit() command (C#) that currently reads one security status/block from a ISO 15693 vicinity RFID card (TI Tag-it HF), to one that will retrieve the security status for all 64 blocks on the card. The existing code is as follows:
Byte[] sendHeader = { 0xFF, 0x30, 0x00, 0x03, 0x05, 0x01, 0x00, 0x00, 0x00, Convert.ToByte(blockNum), 0x01 };
Byte[] sendBuffer = new Byte[255]; //Send Buffer in SCardTransmit
int sendbufferlen; //Send Buffer length in SCardTransmit
SmartCardData pack = new SmartCardData();
sendHeader.CopyTo(sendBuffer, 0);
sendbufferlen = Convert.ToByte(sendHeader.Length);
SCardTransmitReceived rxBuf = SmartCardTransmit(sendBuffer, sendbufferlen);
The way I understand it, the bytes preceding Convert.ToByte(blockNum) represent the command to get a security status, followed by the block in question, and the number of blocks to read. The only reference I have seen regarding security status reads is in section 10.3.4 in the "Contactless Smart Card Reader Dev Guide"
NOTE: SmartCardTransmit takes care of calling SCardTransmit with the correct card handle and the other needed parameters. I'm more interested in the format of the send header that represents a request for security blocks 0 to 63.
Unfortunately, that is not possible. The Get Security Status command of the HID/Omnikey smartcard reader can only retrieve the security status of one block with each command. So regardless of what Le byte you try to provide, the reader will always only return the security status of the block you specify with blockNum.
So the only way to get the security status for all blocks is by iterating through all blocks and issuing the command for each of them:
bool moreBlocks = true;
int blockNum = 0;
while (moreBlocks) {
byte[] sendBuffer = {
0xFF, 0x30, 0x00, 0x03,
0x05,
0x01,
0x00, 0x00,
(byte)((blockNum>>8) & 0xFF), (byte)(blockNum & 0xFF),
0x00
};
SCardTransmitReceived rxBuf = SmartCardTransmit(sendBuffer, sendBuffer.Length);
moreBlocks = check_if_rxBuf_ends_with_sw9000(rxBuf);
++blockNum;
}
From this document: link it appears that your tag complies with ISO15693 standard. From the documentation you have provided it appears that the command you need is at page 59. Now, from the description of the command it appears 0x01 is Version and the following two bytes (0x00 and 0x00) means reading by block. The byte before Convert.ToByte() seams to be the MSB of the starting block (0x00). The Convert.ToByte() is the LSB of the starting block. The next is Le in command description (the number of blocks to be read).
Setting values of bytearray
I have a BYTE data[3]. The first element, data[0] has to be a BYTE with very specific values which are as follows:
typedef enum
{
SET_ACCURACY=0x01,
SET_RETRACT_LIMIT=0x02,
SET_EXTEND_LIMT=0x03,
SET_MOVEMENT_THRESHOLD=0x04,
SET_STALL_TIME= 0x05,
SET_PWM_THRESHOLD= 0x06,
SET_DERIVATIVE_THRESHOLD= 0x07,
SET_DERIVATIVE_MAXIMUM = 0x08,
SET_DERIVATIVE_MINIMUM= 0x09,
SET_PWM_MAXIMUM= 0x0A,
SET_PWM_MINIMUM = 0x0B,
SET_PROPORTIONAL_GAIN = 0x0C,
SET_DERIVATIVE_GAIN= 0x0D,
SET_AVERAGE_RC = 0x0E,
SET_AVERAGE_ADC = 0x0F,
GET_FEEDBACK=0x10,
SET_POSITION=0x20,
SET_SPEED= 0x21,
DISABLE_MANUAL = 0x30,
RESET= 0xFF,
}TYPE_CMD;
As is, if I set data[0]=SET_ACCURACY it doesn't set it to 0x01, it sets it to 1, which is not what I want. data[0] must take the value 0x01 when set it equal to SET_ACCURACY. How do I make it so that it does this for not only SET_ACCURACY, but all the other values as well?
EDIT: Actually this works... I had a different error in my code that I attributed to this. Sorry!
Thanks!
"data[0]=SET_ACCURACY doesn't set it to 0x01, it sets it to 1" It assigns value of SET_ACCURACY to the data[0], which means that bits 00000001 are stored into memory at address &data[0]. 0x01 is hexadecimal representation of this byte, 1 is its decimal representation.