The size of the event ringbuf was previously fixed to compile-time config
value, but it's necessary to sometimes increase this for applications that
have large characteristic buffers to read, or many events at once.
With this commit the size can be set via BLE.config(rxbuf=512), for
example. This also resizes the internal event data buffer which sets the
maximum size of incoming data passed to the event handler.
This allows the user to explicitly select the behaviour of the write to the
remote peripheral. This is needed for peripherals that have
characteristics with WRITE_NO_RESPONSE set (instead of normal WRITE). The
function's signature is now:
BLE.gattc_write(conn_handle, value_handle, data, mode=0)
mode=0 means write without response, while mode=1 means write with
response. The latter was the original behaviour so this commit is a change
in behaviour of this method, and one should specify 1 as the 4th argument
to get back the old behaviour.
In the future there could be more modes supported, such as long writes.
The default protection for the BLE ringbuf is to use
MICROPY_BEGIN_ATOMIC_SECTION, which disables all interrupts. On stm32 it
only needs to disable the lowest priority IRQ, pendsv, because that's the
IRQ level at which the BLE stack is driven.
This removes the limit on data coming in from a BLE.gattc_read() request,
or a notify with payload (coming in to a central). In both cases the data
coming in to the BLE callback is now limited only by the available data in
the ringbuf, whereas before it was capped at (default hard coded) 20 bytes.
Instead of enqueue_irq() inspecting the ringbuf to decide whether to
schedule the IRQ callback (if ringbuf is empty), maintain a flag that knows
if the callback is on the schedule queue or not. This saves about 150
bytes of code (for stm32 builds), and simplifies all uses of enqueue_irq()
and schedule_ringbuf().
The address, adv payload and uuid fields of the event are pre-allocated by
modbluetooth, and reused in the IRQ handler. Simplify this and move all
storage into the `mp_obj_bluetooth_ble_t` instance.
This now allows users to hold on to a reference to these instances without
crashes, although they may be overwritten by future events. If they want
to hold onto the values longer term they need to copy them.
Remove existing scan result events from the ringbuf if the ringbuf is full
and we're trying to enqueue any other event. This is needed so that events
such as SCAN_COMPLETE are always put on the ringbuf.
- Adds an explicit way to set the size of a value's internal buffer,
replacing `ble.gatts_write(handle, bytes(size))` (although that
still works).
- Add an "append" mode for values, which means that remote writes
will append to the buffer.
For consistency with "umachine". Now that weak links are enabled
by default for built-in modules, this should be a no-op, but allows
extension of the bluetooth module by user code.
Also move registration of ubluetooth to objmodule rather than
port-specific.
NimBLE doesn't actually copy this data, it requires it to stay live.
Only dereference when we register a new set of services.
Fixes#5226
This will allow incrementally adding services in the future, so
rename `reset` to `append` to make it clearer.
Internally change the representation of UUIDs to LE uint8* to simplify this.
This allows UUIDs to be easily used in BLE payloads (such as advertising).
Ref: #5186
This is to more accurately match the BLE spec, where intervals are
configured in units of channel hop time (625us). When it was
specified in ms, not all "valid" intervals were able to be
specified.
Now that we're also allowing configuration of scan interval, this
commit updates advertising to match.
This adds two additional optional kwargs to `gap_scan()`:
- `interval_us`: How long between scans.
- `window_us`: How long to scan for during a scan.
The default with NimBLE is a 11.25ms window with a 1.28s interval.
Changing these parameters is important for detecting low-frequency
advertisements (e.g. beacons).
Note: these params are in microseconds, not milliseconds in order
to allow the 625us granularity offered by the spec.
Damien George
Jim Mussared