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Got a Bluetooth connection working

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This commit is contained in:
Adam Greenwood-Byrne 2020-08-10 15:52:54 +01:00
parent 6f9df254a6
commit dfbe5d5375
3 changed files with 108 additions and 49 deletions
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61
part7-bluetooth/bt.c
View file

@ -39,7 +39,6 @@ void bt_writeByte(char byte)
{
while ((mmio_read(ARM_UART0_FR) & 0x20) != 0);
mmio_write(ARM_UART0_DR, (unsigned int)byte);
uart_byte(byte);
}
void bt_flushrx()
@ -83,6 +82,7 @@ enum {
HCI_COMMAND_PKT = 0x01,
HCI_EVENT_PKT = 0x04,
COMMAND_COMPLETE_CODE = 0x0e,
CONNECT_COMPLETE_CODE = 0x0f,
LL_SCAN_ACTIVE = 0x01,
LL_ADV_NONCONN_IND = 0x03
@ -94,23 +94,35 @@ int hciCommandBytes(unsigned char *opcodebytes, unsigned char *data, unsigned ch
{
unsigned char c=0;
uart_writeText("HCI_START\n");
bt_writeByte(HCI_COMMAND_PKT);
bt_writeByte(opcodebytes[0]);
bt_writeByte(opcodebytes[1]);
bt_writeByte(length);
uart_writeText("\n______ DATA:\n");
while (c++<length) bt_writeByte(*data++);
uart_writeText("\nHCI_END\n");
if (bt_waitReadByte() != HCI_EVENT_PKT) return 0;
if (bt_waitReadByte() != COMMAND_COMPLETE_CODE) return 0;
unsigned char code = bt_waitReadByte();
if (code == CONNECT_COMPLETE_CODE) {
if (bt_waitReadByte() != 4) return 0;
unsigned char err = bt_waitReadByte();
if (err != 0) {
uart_writeText("Saw HCI COMMAND STATUS error "); uart_hex(err); uart_writeText("\n");
return 0;
}
if (bt_waitReadByte() == 0) return 0;
if (bt_waitReadByte() != opcodebytes[0]) return 0;
if (bt_waitReadByte() != opcodebytes[1]) return 0;
} else if (code == COMMAND_COMPLETE_CODE) {
if (bt_waitReadByte() != 4) return 0;
if (bt_waitReadByte() == 0) return 0;
if (bt_waitReadByte() != opcodebytes[0]) return 0;
if (bt_waitReadByte() != opcodebytes[1]) return 0;
if (bt_waitReadByte() != 0) return 0;
} else return 0;
return 1;
}
@ -224,6 +236,16 @@ void setLEwhitelist() {
if (!hciCommand(OGF_LE_CONTROL, 0x11, params, 7)) uart_writeText("setLEwhitelist failed\n");
}
void createLEconnection(unsigned char linterval, unsigned char hinterval, unsigned char lwindow, unsigned char hwindow, unsigned char own_address_type, unsigned char filter_policy, unsigned char linterval_min, unsigned char hinterval_min, unsigned char linterval_max, unsigned char hinterval_max) {
unsigned char params[26] = { linterval, hinterval, lwindow, hwindow,
filter_policy,
0, 0xBC, 0xF2, 0xCA, 0x32, 0xBC, 0xAC,
own_address_type,
linterval_min, hinterval_min, linterval_max, hinterval_max,
0, 0, 0x2a, 0x00, 0, 0, 0, 0 };
if (!hciCommand(OGF_LE_CONTROL, 0x0d, params, 25)) uart_writeText("createLEconnection failed\n");
}
void stopScanning() {
setLEscanenable(0, 0);
}
@ -233,12 +255,12 @@ void stopAdvertising() {
}
void startActiveScanning() {
float BleScanUnitsPerSecond = 1600;
float BleScanInterval = 0.8;
float BleScanWindow = 0.4;
float BleScanInterval = 60;
float BleScanWindow = 60;
float BleScanDivisor = 0.625;
unsigned int p = BleScanInterval * BleScanUnitsPerSecond;
unsigned int q = BleScanWindow * BleScanUnitsPerSecond;
unsigned int p = BleScanInterval / BleScanDivisor;
unsigned int q = BleScanWindow / BleScanDivisor;
setLEwhitelist();
setLEscanparameters(LL_SCAN_ACTIVE, lo(p), hi(p), lo(q), hi(q), 0, 1);
@ -247,6 +269,25 @@ void startActiveScanning() {
wait_msec(0x100000);
}
void connect()
{
float BleScanInterval = 60;
float BleScanWindow = 60;
float BleScanDivisor = 0.625;
float connMinFreq = 30; // every 100ms
float connMaxFreq = 50; // every 100ms
float BleGranularity = 1.25;
unsigned int p = BleScanInterval / BleScanDivisor;
unsigned int q = BleScanWindow / BleScanDivisor;
unsigned int min_interval = connMinFreq / BleGranularity;
unsigned int max_interval = connMaxFreq / BleGranularity;
createLEconnection(lo(p), hi(p), lo(q), hi(q), 0, 0, lo(min_interval), hi(min_interval), lo(max_interval), hi(max_interval));
}
void startActiveAdvertising() {
float advertMinFreq = 100; // every 100ms
float advertMaxFreq = 100; // every 100ms

1
part7-bluetooth/bt.h
View file

@ -9,3 +9,4 @@ unsigned char bt_readByte();
void setLEeventmask(unsigned char mask);
void startActiveScanning();
void startActiveAdvertising();
void connect();

27
part7-bluetooth/kernel.c
View file

@ -11,10 +11,14 @@ unsigned int poll_state = 0;
enum {
LE_EVENT_CODE = 0x3e,
LE_CONNECT_CODE = 0x01,
LE_ADREPORT_CODE = 0x02,
HCI_EVENT_PKT = 0x04
};
unsigned int connected = 0;
unsigned int connection_handle = 0;
void poll2(unsigned char byte)
{
switch (poll_state) {
@ -65,7 +69,8 @@ void bt_update()
unsigned char *buf;
while ( (buf = poll()) ) {
if (data_len >= 2 && buf[0] == LE_ADREPORT_CODE) {
if (data_len >= 2) {
if (buf[0] == LE_ADREPORT_CODE) {
unsigned char numreports = buf[1];
if (numreports == 1) {
@ -75,10 +80,8 @@ void bt_update()
unsigned char buf_len = buf[10];
unsigned char ad_len = buf[11];
if (ad_len < data_len &&
buf_len + 11 == data_len - 1) {
if (ad_len < data_len && buf_len + 11 == data_len - 1) {
for (int c=9;c>=4;c--) uart_byte(buf[c]);
buf += 11;
unsigned char rssi = buf[buf_len];
@ -109,6 +112,11 @@ void bt_update()
}
}
}
} else if (buf[0] == LE_CONNECT_CODE && !connected) {
unsigned char status = buf[1];
connection_handle = buf[2] | (buf[3] << 8);
connected = (status == 0 && connection_handle != 0) ? 1 : 0;
}
}
}
}
@ -134,14 +142,19 @@ void main()
unsigned char local_addr[6];
uart_writeText("bt_getbdaddr()\n");
bt_getbdaddr(local_addr);
uart_writeText("\nBD_ADDR is ");
uart_writeText("BD_ADDR is ");
for (int c=5;c>=0;c--) uart_byte(local_addr[c]);
uart_writeText("\n");
// Start scanning for devices around us
/*
uart_writeText("startActiveScanning()\n");
setLEeventmask(0xff);
startActiveScanning();
*/
uart_writeText("connect()\n");
connect();
// Get the Eddystone beacon going
/*
@ -149,6 +162,10 @@ void main()
startActiveAdvertising();
*/
uart_writeText("Waiting for connection...\n");
while (!connected) bt_update();
uart_writeText("Connected - handle "); uart_hex(connection_handle); uart_writeText("\n");
uart_writeText("Waiting for input...\n");
while (1) {
uart_update();