Compatibility with USB Host Shield 2.0 library

[kristofferpeterhansel]

I am trying to combine the Circuits@Home USB Host Shield 2.0 with the RedBearLabs BLE Shield 2.0 to build a bridge from my rowing machine to get data to my phone.

My initial approach was using the RBL_nRF8001 library to abstract somewhat low-level-ness of the BLE library. But then I discovered this BLEPeripheral and figured it would give me a lot more control. So off I went integrating it instead.

I am hitting a bit of an issue though. As it appears that library processing calls (BLEPeripheral::central() and USB::Task()) don't like each other very much. Where calling one will basically break the functionality of the other library. And I can't quite figure out why. Since the RBL_nRF8001 library seemed to co-exist just fine.

I did initially have similar symptom with the RBL_nRF8001 library. But that turned out to simply be conflicts on the use of pin 9. And was easily fixed on the BLE Shield (lucky since it requires soldering on the USB Host shield).

[sandeepmistry]

@kristofferpeterhansel can you share your sketch file? Unfortunately, I don't have the USB Host shield, but I can try to help out via looking at the code ...

Do you think it might be related to memory usage?

[sandeepmistry]

@kristofferpeterhansel any updates on this?

[kristofferpeterhansel]

Ah sorry. Been busy with other things. So hobby projects sort of take the backseat. I'll see if I can't put together a simple example this week.

[sandeepmistry]

No worries, just checking in.

[kristofferpeterhansel]

Right. I made a simple version at https://codebender.cc/sketch:55276.

Basically it seems that the BLE connectivity stops working as soon as I insert a device on the USB Host board. In the example it will stop being discoverable after having connected to it.

The USB Host library is this one: https://github.com/felis/USB_Host_Shield_2.0

[sandeepmistry]

Have you tried removing the delay call from loop? Also, does the USB library change SPI settings?

Can you see how much memory each library takes? I used this lib: https://github.com/maniacbug/MemoryFree

[kristofferpeterhansel]

I don't think the USB changes SPI settings - but then I am not entirely sure exactly what settings it could change and what it would affect.

I did, however, find a post on the RedBear support forum (that currently escapes me) about how the BLE Shield handles SPI somewhat differently from the norm. And that is one reason why the RBL_nRF8001 library introduced a call to check if it is busy. That workaround made that library work with with the USB Host 2.0 library.

I'll try to see if not doing the delay would change anything. And do some memory checks.

[sandeepmistry]

Closing due to inactivity.

[sandeepmistry]

@kristofferpeterhansel if you're still interested in this, I saw something in RBL_nRF8001.

That is not in this library:

ble_begin

Start

    spi_old = SPCR;
    SPI.setBitOrder(LSBFIRST);
    SPI.setClockDivider(SPI_CLOCK_DIV8);
    SPI.setDataMode(SPI_MODE0);

End

    SPCR = spi_old;
    SPI.begin();

ble_do_events

Start

    spi_old = SPCR;
    SPI.setBitOrder(LSBFIRST);
    SPI.setClockDivider(SPI_CLOCK_DIV8);
    SPI.setDataMode(SPI_MODE0);

End

    SPCR = spi_old;

You could try incorporating this into your sketch, before/after BLEPeripheral calls. The calls preserves and swap in/out SPI settings for other SPI devices.

[kristofferpeterhansel]

Thanks for the suggestion. As may have been apparent from my lack of feedback here that I haven't been working a lot on this recently. But I'll see if I can't fit in a go at this soon.

[ymtoh]

Hi,

I'm facing the similar problem that my BLE is no longer detectable once i inserted the code Usb.Task();

I'm not sure whether did I do it correctly on inserting the codes that @sandeepmistry shared.

Below are my code.

#include <RBL_nRF8001.h>
#include <boards.h>
#include <SPI.h>
#include <EEPROM.h>

// for USB Host
#include <adk.h>

// for BLE
static byte buf_len = 0;
byte queryDone = false;
uint32_t timer1;

// for USB Host
USB Usb;
ADK adk(&Usb, "TKJElectronics", // Manufacturer Name
              "ArduinoBlinkLED", // Model Name
              "Example sketch for the USB Host Shield", // Description (user-visible string)
              "1.0", // Version
              "http://www.tkjelectronics.dk/uploads/ArduinoBlinkLED.apk", // URL (web page to visit if no installed apps support the accessory)
              "123456789"); // Serial Number (optional)
uint32_t counter;
uint32_t sendcounter;
uint32_t timer;
bool connected;

void setup() {
  Serial.begin(57600);

  Serial.print("\r\nArduino Blink LED Started");
  if (Usb.Init() == -1) {
    Serial.print("\r\nOSCOKIRQ failed to assert");
    while (1); // halt
  }

  // Init. and start BLE library.
  ble_begin();
}

static unsigned char spi_old;

void loop()
{


  spi_old = SPCR;
    SPI.setBitOrder(LSBFIRST);
    SPI.setClockDivider(SPI_CLOCK_DIV8);
    SPI.setDataMode(SPI_MODE0);

  if(ble_available())
  {
    byte cmd;
    cmd = ble_read();

    Serial.print(cmd, HEX);

    // send out any outstanding data
    ble_do_events();
    buf_len = 0;
  }
  else {
      ble_do_events();

      if (millis() - timer1 >= 1000) { // Send data every 1s
      timer1 = millis();
      Serial.println(F("\nBLE not available"));
     }
  }

  ble_do_events();

  SPCR = spi_old;
  SPI.begin();

  buf_len = 0;

  Usb.Task();
  if (adk.isReady())
  {
    if (!connected) 
    {
      connected = true;
      Serial.println(F("\r\nConnected to accessory"));
    }
  }
  else 
  {  
   if (millis() - timer >= 1000) { // Send data every 1s
      timer = millis();
      Serial.println(F("adk not ready"));
   }
   if (connected) 
   {
      connected = false;
      Serial.print(F("\r\nDisconnected from accessory"));
    }
  } 
}

[sandeepmistry]

@kristofferpeterhansel it doesn't look like you are using BLEPeripheral, so this is not the correct place to discuss it. I suggest opening a new issue here: https://github.com/RedBearLab/nRF8001

[ymtoh]

@sandeepmistry what about the issue that I'm currently facing? I'm kinda stucked right now.

[sandeepmistry]

@ymtoh did you open an issue in https://github.com/RedBearLab/nRF8001?

Sorry, but I can't support the RedBearLab library, you could try using this one. Also, I don't have a USB host shield to test out with.