flightdb – Flight Controller Database, logging and param system

Flight Controller Database Interface

Access to the parameter and logging systems on CodeAIR’s Crazyflie flight controller.

See also Crazyflie Client Library

class codeair.flightdb.LogManager

Interface to query the CF logging framework:

• Retrieve the list of available logging items (TOC) : [(id, type, group, name), …]

• Register new logging configs (log blocks)

• Start/Stop logging

• Also handle fetching of Param TOC, since logic is identical.

This class uses crtp – Crazy Real Time Protocol to implement the log interface

check_catalog_crcs()

Read CRCs from flight controller, return True if they match catalog import

decode_log(blk_id, timestamp_ms, data)

Decode received log values for this block, updating self.cache.

enable(do_enable)

Resume / pause logging. NOTE: Must register_items() FIRST, before enable!

fetch_toc(port, info_only=False)

Request TOC info, either PARAM or LOG based on port (CRTP_PORT_LOG or CRTP_PORT_PARAM)

generate_catalog(filename='new_flight_catalog.py')

Create Python file with log/param TOCs to bake into new CodeAIR builds

register_items(item_list, rate=0.1)

Register and start logging the given list of items. Removes all prior logging. Rate is seconds. item_list contains strings of form ‘group.variable’.

Internals:

• The Crazyflie allows up to 16 “log blocks” to be registered.

• You register a log block by supplying a list of [TYPE8:ID16] tuples referring to TOC items.

• The resulting LOG_CH reports for a block must fit within a 30 byte packet, where 4 bytes are consumed with [BLK_ID_8, TIMESTAMP_24], leaving 26 bytes cumulative payload for log values. This means the max number of IDs you can register in a block depends on the size of the items (8/16/32 bits).

• Ex: you could register up to 6 32-bit items in a log block.

Our Python API exposes a single function to register an id_list, hiding the underlying “log block” system.

• We don’t support dynamically appending/deleting discrete blocks. All are created/removed at once.

• Currently we don’t support different rates for different params. The underlying system has a rate for each block.

• Currently supports only a single log block.

  • TODO: Extend to create up to max (16) blocks to support more log items.

Protocol:

• CRTP(CRTP_PORT_LOG, CONTROL_CH)

• Create block: ( CONTROL_CREATE_BLOCK_V2_8, BLK_ID_8, [TYPE_8, ID_16]*n )

• Delete all: (CONTROL_RESET)

Notes: Successful registration will initialize -

self.cache # {'name': None,...}  # Dict keyed by names from all blocks
self.log_blocks = [
        [name0, name1,...],  # list of names in this block
        decode_fmt_str,  # struct format str for decoding this log block
        val_sz,   # = struct.calcsize(decode_fmt_str)
        reg_fields,  # registration fields (packet payload)
]

Returns:

True if id_list can be registered, False if it would exceed logging payload limits or if list contains an invalid ID.

Return type:

bool

send_ctrl_cmd(cmd, data, callback=None)

Send control channel command, and callback(err_code) upon ACK. Zero means no error.

unregister_all()

Delete all registered log blocks

class codeair.flightdb.ParamManager(log_mgr)

Interface to query the CF parameter framework. Unlike logging, we don’t register for events in the param system.

get(group_dot_name)

Read parameter. Returns data or None.

set(group_dot_name, value)

Set parameter based on dotted name, ex: ‘motorPowerSet.enable’

set_by_name(group_dot_name, type_id, value)

Set param without using TOC lookup (lookup on STM32 instead)

codeair.flightdb.read_crtp(port, channel, timeout_ms=100)

Pump raw rx queue from flight controller, return selected data or None if timeout(ms)

Download Source