Does not work with SD library

[sandeepmistry]

Does not work with SD library

[szotyi007]

I have got a little closer. I have pulled up chip select pin with (digitalWrite(BLE_REQ_PIN), HIGH) before every SD function, and it looks okay now. I guess in the library it is left out.

[sandeepmistry]

@szotyi007 please share your full sketch and pins used etc.

[szotyi007]

please find my code below (I have made it simple to point out the problem):

#include <SPI.h>
#include <SD.h>
#include <stdint.h>
#include <BLEPeripheral.h>
#define BLE_REQ   6
#define BLE_RDY   5
#define BLE_RST   4

BLEPeripheral blePeripheral = BLEPeripheral(BLE_REQ, BLE_RDY, BLE_RST);
BLEService uartService = BLEService("713d0000503e4c75ba943148f18d941e");
BLECharacteristic txCharacteristic = BLECharacteristic("713d0002503e4c75ba943148f18d941e", BLENotify, 20);
BLECharacteristic rxCharacteristic = BLECharacteristic("713d0003503e4c75ba943148f18d941e", BLEWriteWithoutResponse, 20);
BLECentral central = blePeripheral.central();

boolean display_connected = false;

void setup() {
 setup_ble();

 // digitalWrite(6, HIGH); must be used for working..
 if (!SD.begin(8)) {
    Serial.println("initialization failed!");
 }
 File file = SD.open("/");
 file.close();

}

void loop() {
 if (display_connected == false) {
    central = blePeripheral.central();
    if (central) {
      display_connected = true;
      Serial.print("Connected to central: ");
      Serial.println(central.address());
    }
  }
  if (display_connected && central.connected()) {
    if (rxCharacteristic.written()) {
      unsigned char len = rxCharacteristic.valueLength();
      const unsigned char *val = rxCharacteristic.value();
      unsigned char i = 0;
      while (i < len) {
        Serial.write(val[i++]);
      }
    }

    if (txCharacteristic.canNotify()) {
      txCharacteristic.setValue((const unsigned char *)"12345", 21);
    }
  }

  if (display_connected == true && central.connected() == false ) {
    display_connected = false;
    Serial.print("Disconnected from central: ");
    Serial.println(central.address());
  }


}

void setup_ble() {
  blePeripheral.setLocalName("customBle");
  blePeripheral.setAdvertisedServiceUuid(uartService.uuid());

  blePeripheral.addAttribute(uartService);
  blePeripheral.addAttribute(rxCharacteristic);
  blePeripheral.addAttribute(txCharacteristic);


  blePeripheral.begin();

  Serial.println(F("BLE UART Peripheral"));
}

[sandeepmistry]

@szotyi007 what hardware are you using?

[szotyi007]

Arduino Due, with MOLEX 502774-0891 SD socket, Readbearlab shield V 2.1

[szotyi007]

Have you find the cause of the bug? I have found this:

BLE Shield communicates with Arduino through the ACI (Application Controller Interface). The ACI is similar to SPI but does not actually work as SPI. SPI is consist of MOSI, MISO, SCK and SS, whereas ACI is consist of MOSI, MISO, SCK, REQN and RDYN.
Since BLE Shield may receive data anytime even not selected by SPI master (Arduino), so the SS line is not needed.
In ACI,data exchanged still through MOSI and MISO, and SCK provides the clock generated by master.
When master wants to request data from BLE Shield, it puts the REQN to low until RDYN line is put to low by BLE Shield, and then master generates the clock to read out the data. After reading out the data, master will release the REQN and BLE Shield release the RDYN, put them to high.
If BLE Shield has data to transmit to master, it will put the RDYN to low to indicate master, even though master havn't requested data and REQN is idle. If master detectes a low level condition on RDYN, it will put REQN to low and generate the clock to read out the data.After reading out the data, both REQN and RDYN will be put to high.Note that REQN is controlled by master while RDYN is controlled by BLE Shield.

But then, how can I use another SPI device with the BLE shield in the same time?

[sandeepmistry]

@szotyi007 I haven't had time to set this up locally, it would be much easier if you could find a way to reproduce without needing an SD card shield.

Could you please try using a different pin instead of 4 (or 10) for reset?

The lower level nRF8001 SDK already pulls REQ high after each SPI transaction: https://github.com/sandeepmistry/arduino-BLEPeripheral/blob/master/utility/hal_aci_tl.cpp#L209-L212

I'm wondering if something in the SPI or SD card library is changing pin 4 or 6, and possibly reseting the nRF8001.

[szotyi007]

Hi!

Thanks for your email.

I have just left it, i have changed the module to the ble nano..

Thanks again!
Zsolt

On Sun, Mar 6, 2016 at 9:26 PM, Sandeep Mistry [email protected]
wrote:

@szotyi007 https://github.com/szotyi007 I haven't had time to set this
up locally, it would be much easier if you could find a way to reproduce
without needing an SD card shield.

Could you please try using a different pin instead of 4 (or 10) for reset?

The lower level nRF8001 SDK already pulls REQ high after each SPI
transaction:
https://github.com/sandeepmistry/arduino-BLEPeripheral/blob/master/utility/hal_aci_tl.cpp#L209-L212

I'm wondering if something in the SPI or SD card library is changing pin 4
or 6, and possibly reseting the nRF8001.

—
Reply to this email directly or view it on GitHub
#56 (comment)
.

[sandeepmistry]

@szotyi007 ok, I'll close this for now. We can re-open if you or someone else has time to investigate my suggestion on the Due.

[szotyi007]

Ok, no problem. Thanks again!

[JJANANIPRIYA]

@szotyi007
Hi, I'm using Redbearlabs BLE Nano. The code which you have shared with SD library is not compiling for BLE Nano. any idea? or do have any other code which library compatible with BLE nano library? I want to save data from BLE Nano to SD card in my application.

[szotyi007]

Hi,
I have posted the code, because it was not working properly :) At the time I was using the ble shield, and it compiled.
I have tried now with nano, I also get a lot of error by compiling. I am not sure, how much time to fix everything. What I do is that I use the nano only for "gateway" between my ipad and the "main processor". I use a teensy 3.6 with built-in micro sd card slot and communicate with ble nano over general ttl serial. If the nano receives data from ipad (via bluetooth), it forwards the data to teensy (over serial) and do nothing else, and I actually parse data on the teensy. If I need to send information to ipad then I send it from teensy to nano (over serial) and the nano "forwards" to ipad.
A simple version of my code for ble nano:

#include <stdint.h>
#include <SPI.h>
#include <BLEPeripheral.h>

#define BLE_REQ   9
#define BLE_RDY   8
#define BLE_RST   10

BLEPeripheral blePeripheral = BLEPeripheral(BLE_REQ, BLE_RDY, BLE_RST);
BLEService uartService = BLEService("713d0000503e4c75ba943148f18d941e");
BLECharacteristic txCharacteristic = BLECharacteristic("713d0002503e4c75ba943148f18d941e", BLENotify, 20);
BLECharacteristic rxCharacteristic = BLECharacteristic("713d0003503e4c75ba943148f18d941e", BLEWriteWithoutResponse, 20);

BLECentral central = blePeripheral.central();


char buffer[21];
int buffer_counter = 0;
unsigned long buffer_lastmillis = 0;

boolean display_connected = false;

void setup() {
  Serial.begin(38400); // does not work properly with higher baundrate
  pinMode(13, OUTPUT);

  blePeripheral.setLocalName("testName");
  blePeripheral.setAdvertisedServiceUuid(uartService.uuid());

  blePeripheral.addAttribute(uartService);
  blePeripheral.addAttribute(rxCharacteristic);
  blePeripheral.addAttribute(txCharacteristic);

  blePeripheral.begin();

  Serial.println("GNSS BlE starts");

}
unsigned long counter = 0;
unsigned long lastmillis = 0;

void loop() {
  //Serial.println("lol");
  if (millis() - lastmillis > 1000) {
    digitalWrite(13, !digitalRead(13));
    lastmillis = millis();
  }
  central = blePeripheral.central();
  if (display_connected == false) {
    if (central) {
      display_connected = true;
      Serial.print("Connected to central: ");
      Serial.println(central.address());
    }
  }
  if (display_connected && central.connected()) {
    if (rxCharacteristic.written()) {
      unsigned char len = rxCharacteristic.valueLength();
      const unsigned char *val = rxCharacteristic.value();

      unsigned char i = 0;
      while (i < len) {Serial.write(val[i++]);}
      //Serial.println("");
    }

    if (txCharacteristic.canNotify()) {
      // txCharacteristic.setValue((const unsigned char *)"test", 1);
    }
  }

  if (display_connected == true && central.connected() == false ) {
    display_connected = false;
    Serial.print("Disconnected from central: ");
    Serial.println(central.address());
  }

  read_serial();
}


void read_serial() {
  if (Serial.available()) {

    for ( int i = 0; i < sizeof(buffer); i++) buffer[i] = (char)0;
    buffer_counter = 0;

    unsigned long buffer_lastmillis = millis();
    while (Serial.available() || millis() - buffer_lastmillis < 20) {
      if (Serial.available()) {
        char readed_char = Serial.read();
       // Serial.write(readed_char);
        buffer[buffer_counter] = readed_char;
        buffer_counter++;
        buffer_lastmillis = millis();

        if (buffer_counter == 20) {
          while (!txCharacteristic.canNotify()) { // must be modified for timout 
            blePeripheral.connected();
            //delay(20);
          }
          txCharacteristic.setValue((const unsigned char *)buffer, 20);
          for ( int i = 0; i < sizeof(buffer); i++) buffer[i] = (char)0;
          buffer_counter = 0;
        }
      }
    }
    if (buffer_counter > 0) {
      while (!txCharacteristic.canNotify()) { // must be modified for timout
        blePeripheral.connected();
      }
      
      txCharacteristic.setValue((const unsigned char *)buffer, 20);
    }
  }
}

The main reason I have choose this solution because I have to send a lot of data from teensy to iPad, and the BLE is quit slow, and I did not want my main processor to waste time and resources to send the data to my ipad. So i just send all data from teensy to nano, and it buffers and splits the data to 20 bytes packets, and send the packets to ipad as the speed allows. As I remember I had to modify the core serial file to change the buffer size of the incoming serial to not loose any bytes.