void GCS_MAVLINK::handle_param_request_read(mavlink_message_t *msg)
{
mavlink_param_request_read_t packet;
mavlink_msg_param_request_read_decode(msg, &packet);
enum ap_var_type p_type;
AP_Param *vp;
char param_name[AP_MAX_NAME_SIZE+1];
if (packet.param_index != -1) {
AP_Param::ParamToken token;
vp = AP_Param::find_by_index(packet.param_index, &p_type, &token);
if (vp == NULL) {
return;
}
vp->copy_name_token(token, param_name, AP_MAX_NAME_SIZE, true);
param_name[AP_MAX_NAME_SIZE] = 0;
} else {
strncpy(param_name, packet.param_id, AP_MAX_NAME_SIZE);
param_name[AP_MAX_NAME_SIZE] = 0;
vp = AP_Param::find(param_name, &p_type);
if (vp == NULL) {
return;
}
}
float value = vp->cast_to_float(p_type);
mavlink_msg_param_value_send_buf(
msg,
chan,
param_name,
value,
mav_var_type(p_type),
_count_parameters(),
packet.param_index);
}
/**
* @brief Send the next pending parameter, called from deferred message
* handling code
*/
void
GCS_MAVLINK::queued_param_send()
{
if (!initialised || _queued_parameter == NULL) {
return;
}
uint16_t bytes_allowed;
uint8_t count;
uint32_t tnow = hal.scheduler->millis();
// use at most 30% of bandwidth on parameters. The constant 26 is
// 1/(1000 * 1/8 * 0.001 * 0.3)
bytes_allowed = 57 * (tnow - _queued_parameter_send_time_ms) * 26;
if (bytes_allowed > comm_get_txspace(chan)) {
bytes_allowed = comm_get_txspace(chan);
}
count = bytes_allowed / (MAVLINK_MSG_ID_PARAM_VALUE_LEN + MAVLINK_NUM_NON_PAYLOAD_BYTES);
// when we don't have flow control we really need to keep the
// param download very slow, or it tends to stall
if (!have_flow_control() && count > 5) {
count = 5;
}
while (_queued_parameter != NULL && count--) {
AP_Param *vp;
float value;
// copy the current parameter and prepare to move to the next
vp = _queued_parameter;
// if the parameter can be cast to float, report it here and break out of the loop
value = vp->cast_to_float(_queued_parameter_type);
char param_name[AP_MAX_NAME_SIZE];
vp->copy_name_token(_queued_parameter_token, param_name, sizeof(param_name), true);
mavlink_msg_param_value_send(
chan,
param_name,
value,
mav_var_type(_queued_parameter_type),
_queued_parameter_count,
_queued_parameter_index);
_queued_parameter = AP_Param::next_scalar(&_queued_parameter_token, &_queued_parameter_type);
_queued_parameter_index++;
}
_queued_parameter_send_time_ms = tnow;
}