BLE adaption of netdev. More...
BLE adaption of netdev.
BLE defines a very specific environment for the used radio, both in terms of communication sequences and in terms of timings. BLE communication is structured in so called events, where each event is a sequence of request and reply packets send between two peers. A radio context (frequency, CRC initializer, and access address) is used throughout such an event and typically changed for the next one. In addition, the timing of the packets sent in a sequence is fixed to an inter-frame-spacing of exactly 150us.
To cater with these specific attributes of BLE, this interface tailors the generic netdev interface to be used for BLE radios.
To be able to handle the exact inter-packet-spacing if 150us seconds, this interface expects the device driver to stay in a continuous alternating RX-TX sequence, until it is manually aborted. While in this sequence, the radio driver needs to take care of switching to RX mode 150us after sending the last packet, and to send the next packet 150us after the last packet was received.
Such a transmission sequence is started by calling either the radio's send or receive function while the radio is in idle/standby mode.
Once a transmission sequence is in progress, the next packet to be send, or the next reception buffer to be used is specified also using the send/recv functions. They should be called in the
event_callback right after the last transmission (RX or TX) was finished.
The transmission sequence is aborted by calling
netdev->set(dev, NETOPT_BLE_CTX, NULL, 0)). This will put the radio back into idle/standby mode.
As BLE uses time sliced channel hopping, the used channel needs to be set regularly. Additionally, also the used access address and the CRC initializer need to be set regularly, as they differ for different BLE connections. To make setting these values more efficient, this interface combines these three values in to a so called
radio context and adds a
netopt option to set all three values at once using
netdev_ble_set_ctx(dev, ctx) (
netdev->set(dev, NETOPT_BLE_CTX, ctx, sizeof(netdev_ble_ctx_t))).
|BLE specific adaption for the Netdev API. |
|BLE packet structure (as defined by the BLE standard) More...|
|Radio context. More...|
|Maximum payload length of a standard BLE packet. More...|
|Mask for the actual (3 byte) CRC data in the context's CRC field. More...|
|Flag for marking a correct CRC on packet reception. More...|
|static int||netdev_ble_send (netdev_t *dev, netdev_ble_pkt_t *pkt)|
|Send the given packet on the next occasion. More...|
|static int||netdev_ble_recv (netdev_t *dev, netdev_ble_pkt_t *pkt)|
|Start listening for an incoming packet and write it into |
|static void||netdev_ble_set_ctx (netdev_t *dev, netdev_ble_ctx_t *ctx)|
|Set the radio context for the given radio device. More...|
|static void||netdev_ble_stop (netdev_t *dev)|
|Stop the ongoing RX/TX sequence. More...|
|#define NETDEV_BLE_CRC_MASK (0x00ffffff)|
|#define NETDEV_BLE_CRC_OK (0x80000000)|
|#define NETDEV_BLE_PDU_MAXLEN (37U)|
Start listening for an incoming packet and write it into
If a transmission sequence is in progress, the radio will use the given buffer for reception when it goes in to RX mode 150us after sending the last packet. If no sequence is in progress, the radio will go into RX mode immediately (using the given RX buffer), and a new transmission sequence is started.
|[in]||dev||radio to use for receiving|
|[out]||pkt||buffer to write new packet to|
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Send the given packet on the next occasion.
If a transmission sequence is in progress, the given packet will be send after 150us after receptions of the last packet. If no sequence is currently active, the packet will be send immediately and a new transmission sequence is started.
|[in]||dev||radio to use for sending|
|[in]||pkt||data to send|
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