Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Jump to bottom

Update ganglion decompression #655

Merged
merged 5 commits into from
Aug 4, 2023
Merged

Update ganglion decompression #655

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
5 commits
Select commit Hold shift + click to select a range
3a9b248
Detect Ganglion firmware version
philippitts Jul 28, 2023
99e88aa
Add decompression for Ganglion firmware v3
philippitts Jul 28, 2023
4579b82
Support Ganglion firmware v3 for native BLE
philippitts Aug 1, 2023
899f967
Move Ganglion BLE connection parameters definitions to header
philippitts Aug 3, 2023
93dd4a1
Determine Ganglion firmware version after validating advertised name
philippitts Aug 3, 2023
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
251 changes: 156 additions & 95 deletions src/board_controller/openbci/ganglion.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -226,9 +226,7 @@ void Ganglion::read_thread ()
int max_attempts = params.timeout * 1000 / sleep_time;
float last_data[8] = {0};

double accel_x = 0.;
double accel_y = 0.;
double accel_z = 0.;
double acceleration[3] = {0.};

double resist_ref = 0.0;
double resist_first = 0.0;
Expand Down Expand Up @@ -267,72 +265,16 @@ void Ganglion::read_thread ()
safe_logger (spdlog::level::debug, "start streaming");
}

// delta holds 8 nums (4 by each package)
float delta[8] = {0.f};
int bits_per_num = 0;
unsigned char package_bits[160] = {0}; // 20 * 8
for (int i = 0; i < 20; i++)
if (data.data[0] <= 200)
{
uchar_to_bits (data.data[i], package_bits + i * 8);
}

// no compression, used to init variable
if (data.data[0] == 0)
{
// shift the last data packet to make room for a newer one
last_data[0] = last_data[4];
last_data[1] = last_data[5];
last_data[2] = last_data[6];
last_data[3] = last_data[7];

// add new packet
last_data[4] = (float)cast_24bit_to_int32 (data.data + 1);
last_data[5] = (float)cast_24bit_to_int32 (data.data + 4);
last_data[6] = (float)cast_24bit_to_int32 (data.data + 7);
last_data[7] = (float)cast_24bit_to_int32 (data.data + 10);

// scale new packet and insert into result
package[board_descr["default"]["package_num_channel"].get<int> ()] = 0.;
package[board_descr["default"]["eeg_channels"][0].get<int> ()] =
eeg_scale * last_data[4];
package[board_descr["default"]["eeg_channels"][1].get<int> ()] =
eeg_scale * last_data[5];
package[board_descr["default"]["eeg_channels"][2].get<int> ()] =
eeg_scale * last_data[6];
package[board_descr["default"]["eeg_channels"][3].get<int> ()] =
eeg_scale * last_data[7];
package[board_descr["default"]["accel_channels"][0].get<int> ()] = accel_x;
package[board_descr["default"]["accel_channels"][1].get<int> ()] = accel_y;
package[board_descr["default"]["accel_channels"][2].get<int> ()] = accel_z;
package[board_descr["default"]["timestamp_channel"].get<int> ()] = data.timestamp;
push_package (package);
continue;
}
// 18 bit compression, sends delta from previous value instead of real value!
else if ((data.data[0] >= 1) && (data.data[0] <= 100))
{
int last_digit = data.data[0] % 10;
switch (last_digit)
if (firmware == 3)
{
// accel data is signed, so we must cast it to signed char
// due to a known bug in ganglion firmware, we must swap x and z, and invert z.
case 0:
accel_z = -accel_scale * (char)data.data[19];
break;
case 1:
accel_y = accel_scale * (char)data.data[19];
break;
case 2:
accel_x = accel_scale * (char)data.data[19];
break;
default:
break;
decompress_firmware_3 (&data, last_data, acceleration);
}
else if (firmware == 2)
{
decompress_firmware_2 (&data, last_data, acceleration);
}
bits_per_num = 18;
}
else if ((data.data[0] >= 101) && (data.data[0] <= 200))
{
bits_per_num = 19;
}
else if ((data.data[0] > 200) && (data.data[0] < 206))
{
Expand Down Expand Up @@ -401,30 +343,6 @@ void Ganglion::read_thread ()
}
continue;
}
// handle compressed data for 18 or 19 bits
for (int i = 8, counter = 0; i < bits_per_num * 8; i += bits_per_num, counter++)
{
if (bits_per_num == 18)
{
delta[counter] = (float)cast_ganglion_bits_to_int32<18> (package_bits + i);
}
else
{
delta[counter] = (float)cast_ganglion_bits_to_int32<19> (package_bits + i);
}
}

// apply the first delta to the last data we got in the previous iteration
for (int i = 0; i < 4; i++)
{
last_data[i] = last_data[i + 4] - delta[i];
}

// apply the second delta to the previous packet which we just decompressed above
for (int i = 4; i < 8; i++)
{
last_data[i] = last_data[i - 4] - delta[i];
}

// add first encoded package
package[board_descr["default"]["package_num_channel"].get<int> ()] = data.data[0];
Expand All @@ -436,9 +354,9 @@ void Ganglion::read_thread ()
eeg_scale * last_data[2];
package[board_descr["default"]["eeg_channels"][3].get<int> ()] =
eeg_scale * last_data[3];
package[board_descr["default"]["accel_channels"][0].get<int> ()] = accel_x;
package[board_descr["default"]["accel_channels"][1].get<int> ()] = accel_y;
package[board_descr["default"]["accel_channels"][2].get<int> ()] = accel_z;
package[board_descr["default"]["accel_channels"][0].get<int> ()] = acceleration[0];
package[board_descr["default"]["accel_channels"][1].get<int> ()] = acceleration[1];
package[board_descr["default"]["accel_channels"][2].get<int> ()] = acceleration[2];
package[board_descr["default"]["timestamp_channel"].get<int> ()] = data.timestamp;
push_package (package);
// add second package
Expand Down Expand Up @@ -479,6 +397,137 @@ void Ganglion::read_thread ()
delete[] package;
}

void Ganglion::decompress_firmware_3 (
struct GanglionLib::GanglionData *data, float *last_data, double *acceleration)
{
int bits_per_num = 0;
unsigned char package_bits[160] = {0}; // 20 * 8
for (int i = 0; i < 20; i++)
{
uchar_to_bits (data->data[i], package_bits + i * 8);
}

// 18 bit compression, sends 17 MSBs + sign bit of 24-bit sample
if ((data->data[0] >= 0) && (data->data[0] < 100))
{
int last_digit = data->data[0] % 10;
switch (last_digit)
{
// accel data is signed, so we must cast it to signed char
// swap x and z, and invert z to convert to standard coordinate space.
case 0:
acceleration[2] = -accel_scale * (char)data->data[19];
break;
case 1:
acceleration[1] = accel_scale * (char)data->data[19];
break;
case 2:
acceleration[0] = accel_scale * (char)data->data[19];
break;
default:
break;
}
bits_per_num = 18;
}
else if ((data->data[0] >= 100) && (data->data[0] < 200))
{
bits_per_num = 19;
}

// handle compressed data for 18 or 19 bits
for (int i = 8, counter = 0; i < bits_per_num * 8; i += bits_per_num, counter++)
{
if (bits_per_num == 18)
{
last_data[counter] = (float)(cast_ganglion_bits_to_int32<18> (package_bits + i) << 6);
}
else
{
last_data[counter] = (float)(cast_ganglion_bits_to_int32<19> (package_bits + i) << 5);
}
}
}

void Ganglion::decompress_firmware_2 (
struct GanglionLib::GanglionData *data, float *last_data, double *acceleration)
{
int bits_per_num = 0;
unsigned char package_bits[160] = {0}; // 20 * 8
for (int i = 0; i < 20; i++)
{
uchar_to_bits (data->data[i], package_bits + i * 8);
}

float delta[8] = {0.f}; // delta holds 8 nums (4 by each package)

// no compression, used to init variable
if (data->data[0] == 0)
{
// shift the last data packet to make room for a newer one
last_data[0] = last_data[4];
last_data[1] = last_data[5];
last_data[2] = last_data[6];
last_data[3] = last_data[7];

// add new packet
last_data[4] = (float)cast_24bit_to_int32 (data->data + 1);
last_data[5] = (float)cast_24bit_to_int32 (data->data + 4);
last_data[6] = (float)cast_24bit_to_int32 (data->data + 7);
last_data[7] = (float)cast_24bit_to_int32 (data->data + 10);
}
// 18 bit compression, sends delta from previous value instead of real value!
else if ((data->data[0] >= 1) && (data->data[0] <= 100))
{
int last_digit = data->data[0] % 10;
switch (last_digit)
{
// accel data is signed, so we must cast it to signed char
// swap x and z, and invert z to convert to standard coordinate space.
case 0:
acceleration[2] = -accel_scale * (char)data->data[19];
break;
case 1:
acceleration[1] = accel_scale * (char)data->data[19];
break;
case 2:
acceleration[0] = accel_scale * (char)data->data[19];
break;
default:
break;
}
bits_per_num = 18;
}
else if ((data->data[0] >= 101) && (data->data[0] <= 200))
{
bits_per_num = 19;
}

// handle compressed data for 18 or 19 bits
for (int i = 8, counter = 0; i < bits_per_num * 8; i += bits_per_num, counter++)
{
if (bits_per_num == 18)
{
delta[counter] = (float)cast_ganglion_bits_to_int32<18> (package_bits + i);
}
else
{
delta[counter] = (float)cast_ganglion_bits_to_int32<19> (package_bits + i);
}
}

// apply the first delta to the last data we got in the previous iteration
for (int i = 0; i < 4; i++)
{
last_data[i] = last_data[i + 4] - delta[i];
}

// apply the second delta to the previous packet which we just decompressed above
for (int i = 4; i < 8; i++)
{
last_data[i] = last_data[i - 4] - delta[i];
}
}

int Ganglion::config_board (std::string config, std::string &response)
{
const char *conf = config.c_str ();
Expand Down Expand Up @@ -592,7 +641,16 @@ int Ganglion::call_open ()
}

safe_logger (spdlog::level::info, "search for {}", params.mac_address.c_str ());
res = func (const_cast<char *> (params.mac_address.c_str ()));

GanglionLib::ConnectionParameters connection_params;
connection_params.mac_address = const_cast<char *> (params.mac_address.c_str ());
connection_params.firmware = 2;

res = func ((void *)&connection_params);

safe_logger (
spdlog::level::info, "detected firmware version {}", connection_params.firmware);
firmware = connection_params.firmware;
}
else
{
Expand All @@ -605,7 +663,10 @@ int Ganglion::call_open ()

safe_logger (
spdlog::level::info, "mac address is not specified, try to find ganglion without it");
res = func (NULL);

res = func ((void *)&firmware);

safe_logger (spdlog::level::info, "detected firmware version {}", firmware);
}
if (res != GanglionLib::CustomExitCodes::STATUS_OK)
{
Expand Down
16 changes: 13 additions & 3 deletions src/board_controller/openbci/ganglion_bglib/callbacks.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -19,9 +19,11 @@ namespace GanglionLib
{
extern volatile int exit_code;
extern volatile bd_addr connect_addr;
extern volatile uint8 firmware;
extern volatile uint8 connection;
extern volatile uint16 ganglion_handle_start;
extern volatile uint16 ganglion_handle_end;

// recv and send chars handles
extern volatile uint16 ganglion_handle_recv;
extern volatile uint16 ganglion_handle_send;
Expand All @@ -44,6 +46,7 @@ void ble_evt_gap_scan_response (const struct ble_msg_gap_scan_response_evt_t *ms
{
char name[512];
bool name_found_in_response = false;

for (int i = 0; i < msg->data.len;)
{
int8 len = msg->data.data[i++];
Expand All @@ -56,7 +59,7 @@ void ble_evt_gap_scan_response (const struct ble_msg_gap_scan_response_evt_t *ms
break; // not enough data
}
uint8 type = msg->data.data[i++];
if (type == 0x09) // no idea what is 0x09
if (type == 0x09) // Ensure that the device is advertising with a complete name
{
name_found_in_response = true;
memcpy (name, msg->data.data + i, len - 1);
Expand All @@ -68,10 +71,17 @@ void ble_evt_gap_scan_response (const struct ble_msg_gap_scan_response_evt_t *ms

if (name_found_in_response)
{
// strcasestr is unavailable for windows
if (strstr (name, "anglion") != NULL)
// Check if the found device is the one specified by the serial_number parameter
if (memcmp (msg->sender.addr, (uint8 *)GanglionLib::connect_addr.addr, sizeof (bd_addr)) ==
0)
{
GanglionLib::firmware = msg->data.data[0] == 20 && msg->data.data[13] == '3' ? 3 : 2;
GanglionLib::exit_code = (int)GanglionLib::STATUS_OK;
Andrey1994 marked this conversation as resolved.
Show resolved Hide resolved
}
else if (strstr (name, "anglion") != NULL) // strcasestr is unavailable for windows
{
memcpy ((void *)GanglionLib::connect_addr.addr, msg->sender.addr, sizeof (bd_addr));
GanglionLib::firmware = msg->data.data[0] == 20 && msg->data.data[13] == '3' ? 3 : 2;
GanglionLib::exit_code = (int)GanglionLib::STATUS_OK;
}
}
Expand Down
7 changes: 7 additions & 0 deletions src/board_controller/openbci/ganglion_bglib/inc/ganglion_types.h
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -1,6 +1,7 @@
#pragma once

#include "shared_export.h"
#include <cstdint>
#include <string.h>

namespace GanglionLib
Expand Down Expand Up @@ -86,4 +87,10 @@ namespace GanglionLib
INVALID_MAC_ADDR_ERROR = 17,
PORT_OPEN_ERROR = 18
};

struct ConnectionParameters
{
char *mac_address;
uint8_t firmware;
};
}
Loading
Loading