Command ECHO - Non-Buffer Bug

[kb1lqd]

Problem Summary
I found during device testing script creation that the ECHO command in command.c was not reliable when used multiple times in quick succession.

Symptoms

• Data to be ECHO'd is not returned from the unit and is lost occasionally, most notable during high volume use cases

[kb1lqd]

I found that the command.c ECHO command directly implemented the UART Layer 4 transmit routine without a buffer our involvement of the housekeeping routines. This likely causes a race condition where occasionally another function buffer is attempting to transmit and the ECHO data is interjected during a transmission. A function in the housekeeping routing such as telemetry running immediately after an ECHO was placed into the Layer 4 transmit structure could cause issues at first thought.

switch (packet_parsed.command){
			//Command = ECHO
			case 1:
				uart_send(2, 62, packet_parsed.payload);
				break;

void uart_send(unsigned char service_number, unsigned char payload_length, unsigned char *payload){
	uart_transport_tx_packet(service_number,payload_length, payload);
}

unsigned char uart_transport_tx_packet(unsigned char service_number, unsigned char payload_length, unsigned char *payload){
	UART_TRANSPORT_PACKET_STRUCT uart_tx_transport_pkt_struct;
	//Create transport packet
	uart_transport_create_packet(&uart_tx_transport_pkt_struct, service_number, payload_length, payload);
	unsigned char status;
	//Place tranport packet into datalink packet to transmit
	status = uart_datalink_put_tx(0xFF, 0x00, UART_L4_PACKET_LENGTH, &uart_tx_transport_pkt_struct);
	return status;
}