Simple adv_ind with nrf52832

[32mb]

Hello,

I have here nrf52832 installed in a wristwatch called PineTime.

I program nrf52832 directly (only gcc none eabi), completely without SDK and without SoftDevice. This works very well so far.

Now for weeks I try in vain to activate Bluetooth and send ADV_IND. This does not succeed. To receive my tests I have nrf52840-dongle with WireShark. Somehow it doesn't matter what I do. I can not receive anything from my nrf52832. I receive all kinds of other devices around me. But not my nrf52832.

Can someone help me possibly? Or is there somewhere possibly a simple example how sending adv_ind works successfully. Or can you point me to errors in my code?

Thanks in advance.

#define BLUE_TASK_TX_ENABLE             *(volatile unsigned int *) 0x40001000
#define BLUE_TASK_RX_ENABLE             *(volatile unsigned int *) 0x40001004
#define BLUE_TASK_START                 *(volatile unsigned int *) 0x40001008
#define BLUE_TASK_STOP                  *(volatile unsigned int *) 0x4000100C
#define BLUE_TASK_DISABLE               *(volatile unsigned int *) 0x40001010
#define BLUE_EVENT_READY                *(volatile unsigned int *) 0x40001100
#define BLUE_EVENT_ADDRESS              *(volatile unsigned int *) 0x40001104
#define BLUE_EVENT_PAYLOAD              *(volatile unsigned int *) 0x40001108
#define BLUE_EVENT_END                  *(volatile unsigned int *) 0x4000110C
#define BLUE_EVENT_DISABLED             *(volatile unsigned int *) 0x40001110
#define BLUE_SHORTS                     *(volatile unsigned int *) 0x40001200
#define BLUE_INTERRUPT_SET              *(volatile unsigned int *) 0x40001304
#define BLUE_INTERRUPT_CLEAR            *(volatile unsigned int *) 0x40001308
#define BLUE_CRC_STATUS                 *(volatile unsigned int *) 0x40001400
#define BLUE_PACKET_PTR                 *(volatile unsigned int *) 0x40001504
#define BLUE_FREQUENCY                  *(volatile unsigned int *) 0x40001508
#define BLUE_TX_POWER                   *(volatile unsigned int *) 0x4000150C
#define BLUE_MODE                       *(volatile unsigned int *) 0x40001510
#define BLUE_PACKET_CONFIG_0            *(volatile unsigned int *) 0x40001514
#define BLUE_PACKET_CONFIG_1            *(volatile unsigned int *) 0x40001518
#define BLUE_BASE_ADDRESS_0             *(volatile unsigned int *) 0x4000151C
#define BLUE_BASE_ADDRESS_1             *(volatile unsigned int *) 0x40001520
#define BLUE_PREFIX_ADDRESS_0           *(volatile unsigned int *) 0x40001524
#define BLUE_PREFIX_ADDRESS_1           *(volatile unsigned int *) 0x40001528
#define BLUE_TX_ADDRESS                 *(volatile unsigned int *) 0x4000152C
#define BLUE_RX_ADDRESSES               *(volatile unsigned int *) 0x40001530
#define BLUE_CRC_CONFIG                 *(volatile unsigned int *) 0x40001534
#define BLUE_CRC_POLY                   *(volatile unsigned int *) 0x40001538
#define BLUE_CRC_INIT                   *(volatile unsigned int *) 0x4000153C
#define BLUE_STATE                      *(volatile unsigned int *) 0x40001550
#define BLUE_DATA_WHITENING_INIT_VALUE  *(volatile unsigned int *) 0x40001554
#define BLUE_RADIO_MODE_CONFIG          *(volatile unsigned int *) 0x40001650
#define BLUE_POWER                      *(volatile unsigned int *) 0x40001FFC

#define BLUETOOTH_STATE_DISABLED        0
#define BLUETOOTH_STATE_RX_RU           1
#define BLUETOOTH_STATE_RX_IDLE         2
#define BLUETOOTH_STATE_RX              3
#define BLUETOOTH_STATE_RX_DISABLE      4
#define BLUETOOTH_STATE_TX_RU           9
#define BLUETOOTH_STATE_TX_IDLE         10
#define BLUETOOTH_STATE_TX              11
#define BLUETOOTH_STATE_TX_DISABLE      12


static unsigned char blue_ram_tx_buffer[256];


// Bluetooth

//     Data
blue_ram_tx_buffer [ 0] = 0x00;                               // BLE Header (PDU_TYPE: SCAN_REQ, TXadd, RXadd)
blue_ram_tx_buffer [ 1] = 0x0C;                               // Length of payload: 12
blue_ram_tx_buffer [ 2] = 0xDE;                               // InitAddr LSByte first
blue_ram_tx_buffer [ 3] = 0xDE;
blue_ram_tx_buffer [ 4] = 0xDE;
blue_ram_tx_buffer [ 5] = 0xDE;
blue_ram_tx_buffer [ 6] = 0xDE;
blue_ram_tx_buffer [ 7] = 0xDE;
blue_ram_tx_buffer [ 8] = 0xAA;                               // AdvAddr LSByte first
blue_ram_tx_buffer [ 9] = 0xAA;
blue_ram_tx_buffer [10] = 0xAA;
blue_ram_tx_buffer [11] = 0xAA;
blue_ram_tx_buffer [12] = 0xAA;
blue_ram_tx_buffer [13] = 0xAA;


//    Bluetooth Reset
BLUE_POWER = 0; // Bluetooth PowerOFF
for (unsigned int i=0xFF;i>0;i--) {;} // Small break (how long, not defined anywhere)
BLUE_POWER = 1; // Bluetooth PowerON

//    Bluetooth Set signal strength 
BLUE_TX_POWER = 0; //   0 dBm

//    Frequency for transmission
BLUE_FREQUENCY = 2; // 2402 MHz - Corresponds to channel 37

//    Datawhithening Init
BLUE_DATA_WHITENING_INIT_VALUE = 0xFF; // Is that correct?

//    Advertising Address 0x8E89BED6
BLUE_PREFIX_ADDRESS_0 = 0x8E;
BLUE_BASE_ADDRESS_0 = 0x89BED600;

//    Select Address
BLUE_TX_ADDRESS = 0x00; // (prefix0 + base0) = 0x8E89BED6
BLUE_RX_ADDRESSES = 0x01;

// Radio Mode
BLUE_MODE = 3; // 3 - BLE 1Mbit

// Radio config
BLUE_RADIO_MODE_CONFIG = 1 | (2 << 8); // Fast Ramp-Up + Transmit-Center-Frequency

//    Konfiguration 
BLUE_PACKET_CONFIG_0 = 0; // 0 - LFLEN (bits); 0 - S0 (bytes); 0 - S1 (bits);
BLUE_PACKET_CONFIG_1 = 15 | (3 << 16) | (1 << 25); // 15 - Maxlen; 3 - Balen; 1 - Whiteening

//    CRC Config
BLUE_CRC_CONFIG = 3 | (1 << 8); // 3 - CRC-Bytes; 1 - Exclude address
BLUE_CRC_INIT = 0x00555555; // Initial value CRC (24 Bit)
BLUE_CRC_POLY = 0x0000065B; // Would be standart for BLE (24 Bit)

//    Clear events
BLUE_EVENT_READY = 0;
BLUE_EVENT_END = 0;
BLUE_EVENT_ADDRESS = 0;
BLUE_EVENT_PAYLOAD = 0;
BLUE_EVENT_DISABLED = 0;

//    PTR to Data
BLUE_PACKET_PTR = (unsigned int) &blue_ram_tx_buffer;

//    Radio Ramp Up
BLUE_TASK_RX_ENABLE = 0;
BLUE_TASK_TX_ENABLE = 1;

//    Wait until radio is ready
while (BLUE_EVENT_READY == 0) {;}
while (BLUE_STATE != BLUETOOTH_STATE_TX_IDLE) {;}


//    Start radio TX
BLUE_TASK_START = 1;

[haakonsh]

Is you board capable of transmitting?

Have you tested your custom board with any of our BLE examples? 

[32mb]

of course, the original firmware, in my case from PineTime, works and is able to send.

I think I made a mistake somewhere, for example in the access address (Prefix+Base) or possibly several errors in different places at the same time.

The radio goes through all the states as described in the instructions for nrf52832-v1.4 under the point 23.7. These states can be read from the register 0x40001550. After initiating and starting the radio goes normally into TX and then into TXIDLE. Everything as it should be, except that I can not receive anything.

[haakonsh]

You need some form of physical measurements to determine what exactly is going on, as well as comparing the radio events with the radio state machine described in Figure 6. Radio states. 

You should also double-check that the endianess for the various packet fields are correct. 

I'm not sure if the data whitening register needs a given seed, you'll need to read the BT core spec to verify.

[32mb]

I was hoping to save hundreds on diagnostic equipment by getting a working example somewhere (would be perfect if from the manufacturer).

I have already looked at several projects. But they are either incredibly complicated to understand or I'm doing something wrong myself.

For example: https://github.com/NordicPlayground/nRF51-multi-role-conn-observer-advertiser/blob/master/btle_hci/scanner/radio.c

Theoretically I do everything described there, but it doesn't work for me.

Is there anywhere I can get paid support, where I can get my problem solved?

[haakonsh]

Why you are not using any of the already working solutions for this problem? Be it one of our SDKs or a third-party one. If PinteTime is running MyNewt, why not use its NimBLE stack?

[32mb]

Why don't you tell me how it works without SDK's? =)

I will transfer 200 € to anyone for a working and understandable example of controlling the radio by register. Or for the correction of my code so that it works. So that the radio sends receivable adv_ind packet.

[haakonsh]

See BLUETOOTH CORE SPECIFICATION Version 5.3 | Vol 6, Part B 

Chapter 3.1.1 CRC generation: 
"...For all other Advertising Physical Channel PDUs, the shift register shall be preset with 0x555555."

Chapter 3.2: DATA WHITENING:
"Before whitening or dewhitening, the shift register is initialized with a sequence that is derived from the physical channel index in which the packet is transmitted in the following manner:

• Position 0 is set to one.
• Positions 1 to 6 are set to the channel index of the channel used when transmitting or receiving, from the most significant bit in position 1 to the least significant bit in position 6.

For example, if the channel index = 23 (0x17), the positions would be set as follows:
Position 0 = 1
Position 1 = 0
Position 2 = 1
Position 3 = 0
Position 4 = 1
Position 5 = 1
Position 6 = 1"

[32mb]

Thanks for the suggestion. According to nRF52832 documentation PDF at 23.14.26 for register 0x40001554:

Data whitening initial value: Bit 6 is hard-wired to '1', writing '0' to it has no effect, and it will always be read back and used by the device as '1'. Bit 0 corresponds to Position 6 of the LSFR, Bit 1 to Position 5, etc.

So it is enough to write here only the channel index. Which I have also done. But this does not bring me to the result that I can receive anything.

CRC is already initialized with 0x555555. CRCPOLY I have initialized with 0x65B (there I do not know yet whether it is correct).

Thus, I tried the suggested. Problem is not solved yet. I still need help. And the money is still waiting for its recipient, which helps me decisively here. Suggestions and recommendations are also welcome

[haakonsh]

What does BT core spec say on the matter of the CRC polynomial?

[32mb]

There I did not find much understandable, on the value of 0x65B I came, because I saw it here so: https://github.com/NordicPlayground/nRF51-multi-role-conn-observer-advertiser/blob/master/btle_hci/scanner/radio.c

I don't know if the accuracy CRC or whitening gets us anywhere at all. I receive via USB dongle also many erroneous packets (CRC is wrong). So I suppose even if CRC is calculated wrong, packet will still be sent and will be able to be received.

Do you know if I still need to initialize any hardware to make bluetooth radio work? Maybe I forgot to initialize something else?