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Network general


typedef uint16_t mira_link_metric_t;

The link metric (as a 9.7 fixed point number) is a quality index of a particular link between two nodes. The value is called ETX, which is an approximate number of transmissions required for a successful transfer. Range is from 1.0 (0x0080) to infinity (0xFFFF). A value of 1.0 means a perfect link. Higher numbers are worse. To calculate an approximate packet delivery rate use the following formula: PDR = 1.0 / ETX.


typedef uint8_t mira_net_antenna_t;

Antenna index type.



States of network association.

Name Description
MIRA_NET_STATE_NOT_ASSOCIATED The node is not part of a network yet.
MIRA_NET_STATE_IS_COORDINATOR Tells if the node is the coordinator (root).
MIRA_NET_STATE_ASSOCIATED The node is in sync, but has no parent yet.
MIRA_NET_STATE_JOINED The node has a parent and can send packets. Packets may not be routable to this node.


Recommended data rates.

Name Description


Network mode.

MIRA_NET_MODE_ROOT acts as the root node for a network. When starting it tries to reconnect to a previous network, for quicker root restarts. The drawback is that new networks will take longer to start. MIRA_NET_MODE_ROOT is useful for production networks where root restarts may occur.

MIRA_NET_MODE_ROOT_NO_RECONNECT is equal to MIRA_NET_MODE_ROOT, except it doesn’t try to reconnect to the network. It will immediately announce the network to other nodes, making it faster for initial network build. MIRA_NET_MODE_ROOT_NO_RECONNECT is useful during development, to get fast test cycles.

During normal operation, MIRA_NET_MODE_ROOT and MIRA_NET_MODE_ROOT_NO_RECONNECT is equal.

MIRA_NET_MODE_MESH is for mesh nodes that can route packets for other nodes.

MIRA_NET_MODE_LEAF are for leaf nodes. They use less energy than mesh nodes, but can not route messages.

Name Description



Network configuration.

Name Type Description
pan_id uint32_t Network ID.

Network ID, must be same for all nodes in the network.

The Pan ID shall be a 32-bit value, that meets the following requirements:

It shall not be the Access Address for BLE advertisements (0x8E89BED6).

It shall not have a sequence that only differs one bit from any other known PAN ID or BLE advertisement Access Address.

It shall have a minimum of two transitions in the most significant six bits.

It shall have no more than six consecutive zeros or ones.

It shall have no more than 24 transitions.

It shall not have all four octets equal.

key uint8_t[16] Encryption key.

The encryption key for all data in the network. Must be the same for all nodes in the network.

mode mira_net_mode_t Mode of operation.

Set to mesh/leaf/root depending on desired mode of operation.

Not all modes may be supported by all builds. If not supported, mira_net_init() will fail with MIRA_ERROR_INVALID_VALUE

rate uint8_t Rate of network.

Higher value of rate reduces power consumption at the expense of data rate.

Different nodes in the network may have different rates, and routes with higher rates are preferred over routes with lower rates.

Recommended values are defined in mira_net_rate_t.

Rates 0 to 10 are supported for meshing nodes and root node. Rates 0 to 12 are supported for leaf nodes.

Rates 13 and higher are not supported.

antenna mira_net_antenna_t Preferred antenna.

The preferred antenna. If the specified antenna is not available on the module, the default antenna is selected.

prefix const mira_net_address_t * Custom network prefix.

If unset, fd00::/64 is default.

This parameter only applies when mode == MIRA_NET_MODE_ROOT or MIRA_NET_MODE_ROOT_NO_RECONNECT, for other modes, the prefix is derived from the joined network.

Only first /64 is used.

max_nbrs mira_size_t Size of neighbour table.

The neighbour table defines the number of nodes available within reach. It tracks the other nodes within hearable distance.

If unset (or set do 0), the default value of 64 is set.

max_links mira_size_t Size of link table.

The link table tracks the topology of the entire network. Each node needs to have a slot in the link table.

The link table only applies to root nodes, and is ignored on mesh or leaf nodes.

If unset (or set do 0), the default value of 250 is set.

tx_queue_size uint8_t Size of the TX queue.

A value of less than eight uses the default size of eight.



mira_status_t mira_net_init(const mira_net_config_t *config);

Initialize the mira network.


Name Description
config Network configuration.

Return value

Name Description
MIRA_SUCCESS Mira net successfully initialized.
MIRA_ERROR_INVALID_VALUE Unsupported configuration parameters.
MIRA_ERROR_UNKNOWN An unknown error occurred.


int mira_net_is_init(void);

Tells if mira_net_init has been called.

Return value

Name Description
0 mira_net_init has not been called.


mira_status_t mira_net_get_address(mira_net_address_t *dst);

Get the IP address.


Name Description
dst The destination where to store the retrieved IP address.

Return value

Name Description
MIRA_SUCCESS IP address stored successfully.


mira_net_state_t mira_net_get_state(void);

Get the current state of network association.

Please note that there is no way to locally see if this node is reachable from other nodes unless they send a packet to it. The joined state means this node is able to send packets to other nodes.

Return value

Name Description
MIRA_NET_STATE_IS_COORDINATOR Node state is coordinator.
MIRA_NET_STATE_NOT_ASSOCIATED Node state is not associated.
MIRA_NET_STATE_ASSOCIATED Node state is associated.
MIRA_NET_STATE_JOINED Node state is joined.


mira_status_t mira_net_get_root_address(mira_net_address_t *dst);

Get the IP address of the root node.


Name Description
dst The destination where to store the retrieved IP address of the root node.

Return value

Name Description
MIRA_SUCCESS Got valid address.
MIRA_NET_ERROR_NOT_ASSOCIATED Node is not associated.


mira_status_t mira_net_get_parent_address(mira_net_address_t *dst);

Gets the IP address of the parent node.


Name Description
dst The destination where to store the retrieved IP address of the parent.

Return value

Name Description
MIRA_SUCCESS Got valid address.
MIRA_NET_ERROR_NOT_ASSOCIATED Node is not associated.
mira_link_metric_t mira_net_get_parent_link_metric(void);

Gets the link quality metric to the parent node.


mira_status_t mira_net_reset_scanning(void);

Reset network scanning.

Network scanning will timeout after 5 minutes and sleep to conserve battery power in the case that there is no network to join. The sleep period is 5 minutes the first time, and doubles after each active scan period. The sleep period cannot be longer than 23 hours.

Return value

Name Description
MIRA_SUCCESS Scanning reset successfuly.


mira_status_t mira_net_rejoin(void);

Rejoin the network.

When joined, the node will leave the network and start scanning. If already scanning, will reset the network scanning.

Return value

Name Description
MIRA_SUCCESS Network left successfully.


mira_bool_t mira_net_is_reachable(const mira_net_address_t *address);

Is the node reachable?

This function tells if a node is reachable.

A MIRA_TRUE return value does not guarentee that sent messages will reach the node. This function will continue to return MIRA_TRUE for many hours after a node has failed or if the network has become partitioned.


This function only works on root nodes.