main.c File Reference

Program entrypoint and synchronization controller Point-to-Point Laser Diode Transmitter https://github.com/CyberSamurai0/P2P-Transmitter. More...

#include "packet.h"
#include "packet-queue.h"
#include <stdlib.h>
#include <stdio.h>
#include "pico/stdlib.h"
#include "hardware/gpio.h"
#include <sys/select.h>
#include "pico/cyw43_arch.h"

Macros
#define	USE_ONBOARD_LED   1
	If the Pi Pico module used does not have an onboard LED, set this to 0.
#define	TX_PIN   0
#define	RX_PIN   1
#define	BAUD_RATE   20
#define	PACKET_CACHE_SIZE   8
#define	TX_PacketLength   12

Functions
void	setOnboardLED (bool state)
	Sets the Raspberry Pi Pico W onboard LED to be on or off.
void	cachePacket (Packet *p)
	Add a Packet to PacketCache and set its identifier to its index within the cache.
int64_t	TX_FinishedSendingBit (alarm_id_t id, __unused void *user_data)
	Callback function to trigger transmission of the next bit in the sequence.
int64_t	RX_ReadNextBit (alarm_id_t id, __unused void *user_data)
void	RX_PinStateChanged (uint gpio, uint32_t events)
void	stdinCharsAvailable (void *queue)
int	main ()
	Entrypoint function for the program.

Variables
Packet *	PacketCache [PACKET_CACHE_SIZE] = {NULL}
	Caches the most recently transmitted packets to support retransmission.
int	PacketCacheIndex = 0
	The current usable index of PacketCache. This should reset to 0 if it exceeds the length of PacketCache.
Packet *	TX_Packet = NULL
	Contains a pointer to the packet we are currently transmitting.
bool	TX_PacketBits [TX_PacketLength] = {}
uint8_t	TX_BitIndex = 0
	Contains the index of the bit within the packet that we are currently transmitting.
alarm_id_t	TX_Alarm = 0
	Stores the alarm_id used to delay sending the next bit without sleeping.
bool	RX_PacketBits [TX_PacketLength-1] = {}
uint8_t	RX_BitIndex = 0
alarm_id_t	RX_Alarm = 0
bool	RX_Started = 0

Detailed Description

Program entrypoint and synchronization controller Point-to-Point Laser Diode Transmitter https://github.com/CyberSamurai0/P2P-Transmitter.

Macro Definition Documentation

USE_ONBOARD_LED

#define USE_ONBOARD_LED   1

If the Pi Pico module used does not have an onboard LED, set this to 0.

Todo

Adjust configuration based on your own hardware!

Function Documentation

cachePacket()

void cachePacket

(

Packet *

p

)

Add a Packet to PacketCache and set its identifier to its index within the cache.

Warning

Packets should not be cached until they have been dequeued (transmitted), otherwise we may free them too early

Parameters

p	Pointer to the Packet to be cached

main()

int main

(

)

Entrypoint function for the program.

Returns

Status code

State of the onboard LED, used for status indication

Store created Packets until they can be transmitted in sequence

Warning

This is always zero because we are never computing parity for created packets

RX_ReadNextBit()

int64_t RX_ReadNextBit	(	alarm_id_t	id,
		__unused void *	user_data )

Warning

we are maxing out at 8 bits here!

setOnboardLED()

void setOnboardLED

(

bool

state

)

Sets the Raspberry Pi Pico W onboard LED to be on or off.

Parameters

state

Boolean representing whether the light should be on or off

TX_FinishedSendingBit()

int64_t TX_FinishedSendingBit	(	alarm_id_t	id,
		__unused void *	user_data )

Callback function to trigger transmission of the next bit in the sequence.

Parameters

id	The alarm_id_t that expired, triggering this function
user_data	Allow passing additional values without use of globals