The touch injector: a GT911 emulator at 0x14 that presses where a USB (Universal Serial Bus) command line tells it to. Pure C; the RP2350 build (../rp2350) wires it to the I2C (Inter-Integrated Circuit) target, the USB serial port and the status LED, and the host suite drives it as a panel and a host would. More...

#include <stdbool.h>
#include <stddef.h>
#include <stdint.h>
#include "gt911_emu.h"
#include "inj_line_id.h"

Data Structures
struct	inj_contact_t
	One contact id's gesture. More...
struct	injector_t
	The whole injector: protocol, contacts, frames and replies. More...

Macros
#define	INJ_PROTOCOL 1
	The line protocol's version, in the ping's reply.
#define	INJ_RES_X 1024u
	The resolution the injector reports: the panel's 1024 columns.
#define	INJ_RES_Y 600u
	The resolution the injector reports: the panel's 600 rows.
#define	INJ_LINE_MAX 63u
#define	INJ_REPORT_MS 10u
#define	INJ_ACK_TIMEOUT_MS 100u
#define	INJ_TAP_MS 100u
#define	INJ_MS_MAX 30000u
#define	INJ_SWIPE_STEP_PX 100u
#define	INJ_LIVE_MS 100u
#define	INJ_CONTACTS GT911_EMU_POINTS
	Contacts down at once: the GT911's 5 points.
#define	INJ_ID_MAX 15u
	The highest contact id: ids are 0 to 15.
#define	INJ_REPLY_LEN 128u
	A reply line's buffer: 128 characters.
#define	INJ_REPLIES 8u
	The replies queued: 8.

Enumerations
enum	inj_state_t { INJ_LISTEN = 0 , INJ_ACTIVE }
	The injector's state: LISTEN after a reset, ACTIVE once confirmed. More...
enum	inj_gesture_t { INJ_G_NONE = 0 , INJ_G_TAP , INJ_G_HOLD , INJ_G_SWIPE , INJ_G_RELEASE }
	What a contact is doing. More...
enum	inj_led_t { INJ_LED_LISTEN = 0 , INJ_LED_WIRING_BAD , INJ_LED_OFF , INJ_LED_POLLED , INJ_LED_DOWN , INJ_LED_FAILED }
	What the status LED shows. More...

Functions
void	injector_init (injector_t *in)
	Reset: LISTEN, no contacts, no replies.
void	injector_input (injector_t in, const char bytes, size_t n, uint32_t now_ms)
	Bytes from the host. A full line runs at once.
void	injector_poll (injector_t *in, uint32_t now_ms)
	Move the gestures on: frames, acknowledges, timeouts. Call often.
bool	injector_take_wiring (injector_t *in)
	True once after wiring: the glue starts listening to the lines.
void	injector_wiring_done (injector_t in, const inj_line_result_t r)
	The glue's 500ms of listening, classified.
bool	injector_take_attach (injector_t *in)
	True once after confirm: the glue attaches the I2C target.
void	injector_host_closed (injector_t *in)
	The host closed the port (DTR, data terminal ready, fell).
bool	injector_take_reply (injector_t in, char out, size_t n)
	The oldest reply.
inj_led_t	injector_led (const injector_t *in, uint32_t now_ms)
	What the status LED shows at `now_ms`.
const char *	inj_gesture_name (inj_gesture_t g)
	The gesture's word.

Detailed Description

The touch injector: a GT911 emulator at 0x14 that presses where a USB (Universal Serial Bus) command line tells it to. Pure C; the RP2350 build (../rp2350) wires it to the I2C (Inter-Integrated Circuit) target, the USB serial port and the status LED, and the host suite drives it as a panel and a host would.

States:

LISTEN after every reset. GP4 and GP5 are inputs and nothing answers on the bus. wiring asks the glue to listen to the bus for 500ms and report which line carries SCL; confirm scl=GP5 after an ok verdict asks it to attach the I2C target. ACTIVE the target answers at 0x14 and gestures run.

Commands (one line each, at most INJ_LINE_MAX characters, LF or CRLF):

ping pong rcbench-touch 1 addr=0x14 res=1024x600 state=listen|active id=9INJ wiring ok wiring, then the verdict line confirm scl=GP5 ok confirm status status <state> reads= acks= last_read_ms= down= x= y= (contact 0) contacts contacts n= <id>=<gesture>,<down>,<x>,<y> for each contact under way tap x y [ms] [id=N] ok tap, then done tap frames= ms= hold x y ms [id=N] ok hold, then done hold frames= ms= swipe x0 y0 x1 y1 ms [id=N] ok swipe, then done swipe frames= ms= slowed= release [id=N] ok release (each gesture under way first gets fail <gesture> released)

Contacts: up to INJ_CONTACTS gestures run at once, one per contact id 0..INJ_ID_MAX, each a GT911 track ID. A command without id= drives contact 0, and its replies are the ones of protocol 1. A gesture started with id=N names the contact in every reply about it: ok tap id=N, done tap id=N frames= ms=, fail tap id=N released. release without id= releases every contact. A frame carries every contact that is down; a contact's frames= counts the frames that put it down, moved it or lifted it.

Coordinates are panel pixels, x 0..INJ_RES_X-1 and y 0..INJ_RES_Y-1; ms is 1..INJ_MS_MAX. Errors are one line, err <code> [detail], and the command is not run. A gesture that fails after its ok gets fail <gesture> no_master, panel_reset or released; no_master and panel_reset end every contact.

Concurrency: the byte functions of the emulator (gt911_emu.h) run in the I2C interrupt. injector_input() and injector_poll() read and change the same state, so the glue calls them with that interrupt masked.

SPDX-License-Identifier: MIT

Macro Definition Documentation

◆ INJ_ACK_TIMEOUT_MS

#define INJ_ACK_TIMEOUT_MS 100u

a frame not acknowledged by then

◆ INJ_LINE_MAX

#define INJ_LINE_MAX 63u

characters, without the LF

◆ INJ_LIVE_MS

#define INJ_LIVE_MS 100u

a read this recent: panel polling

◆ INJ_MS_MAX

#define INJ_MS_MAX 30000u

the longest gesture

◆ INJ_REPORT_MS

#define INJ_REPORT_MS 10u

least time between two frames

◆ INJ_SWIPE_STEP_PX

#define INJ_SWIPE_STEP_PX 100u

|dx|+|dy| between two swipe frames

◆ INJ_TAP_MS

#define INJ_TAP_MS 100u

a tap's default length

Enumeration Type Documentation

◆ inj_gesture_t

enum inj_gesture_t

What a contact is doing.

Enumerator
INJ_G_NONE	idle
INJ_G_TAP	tap x y [ms]
INJ_G_HOLD	hold x y ms
INJ_G_SWIPE	swipe x0 y0 x1 y1 ms
INJ_G_RELEASE	the lift after release or a closed port

◆ inj_led_t

enum inj_led_t

What the status LED shows.

Enumerator
INJ_LED_LISTEN	white, blinking 1Hz
INJ_LED_WIRING_BAD	yellow: swapped, low or noise
INJ_LED_OFF	active, no read for INJ_LIVE_MS
INJ_LED_POLLED	dim green: the panel reads 0x14
INJ_LED_DOWN	blue: a contact is down
INJ_LED_FAILED	red: the last gesture failed

◆ inj_state_t

enum inj_state_t

The injector's state: LISTEN after a reset, ACTIVE once confirmed.

Enumerator
INJ_LISTEN	nothing answers on the bus
INJ_ACTIVE	the target answers at 0x14, gestures run

Function Documentation

◆ inj_gesture_name()

const char * inj_gesture_name ( inj_gesture_t g )

The gesture's word.

Parameters

g	The gesture.

Returns: tap, hold, swipe, release, or idle.

◆ injector_host_closed()

void injector_host_closed ( injector_t * in )

The host closed the port (DTR, data terminal ready, fell).

Every contact that is down is released; nothing is replied.

Parameters

in	The injector.

◆ injector_init()

void injector_init ( injector_t * in )

Reset: LISTEN, no contacts, no replies.

Parameters

in	The injector.

◆ injector_input()

void injector_input	(	injector_t *	in,
		const char *	bytes,
		size_t	n,
		uint32_t	now_ms )

Bytes from the host. A full line runs at once.

Parameters

in	The injector.
bytes	The bytes.
n	How many.
now_ms	The clock.

◆ injector_led()

inj_led_t injector_led	(	const injector_t *	in,
		uint32_t	now_ms )

What the status LED shows at now_ms.

Parameters

in	The injector.
now_ms	The clock.

Returns: The colour.

◆ injector_poll()

void injector_poll	(	injector_t *	in,
		uint32_t	now_ms )

Move the gestures on: frames, acknowledges, timeouts. Call often.

Parameters

in	The injector.
now_ms	The clock.

◆ injector_take_attach()

bool injector_take_attach ( injector_t * in )

True once after confirm: the glue attaches the I2C target.

Parameters

in	The injector.

Returns: Whether to attach.

◆ injector_take_reply()

bool injector_take_reply	(	injector_t *	in,
		char *	out,
		size_t	n )

The oldest reply.

Parameters

in	The injector.
out	Where it goes.
n	The size of `out`.

Returns: False when there is none.

◆ injector_take_wiring()

bool injector_take_wiring ( injector_t * in )

True once after wiring: the glue starts listening to the lines.

Parameters

in	The injector.

Returns: Whether to start.

◆ injector_wiring_done()

void injector_wiring_done	(	injector_t *	in,
		const inj_line_result_t *	r )

The glue's 500ms of listening, classified.

Parameters

in	The injector.
r	The verdict.

Data Structures

Macros

Enumerations

Functions

Detailed Description

Macro Definition Documentation

◆ INJ_ACK_TIMEOUT_MS

◆ INJ_LINE_MAX

◆ INJ_LIVE_MS

◆ INJ_MS_MAX

◆ INJ_REPORT_MS

◆ INJ_SWIPE_STEP_PX

◆ INJ_TAP_MS

Enumeration Type Documentation

◆ inj_gesture_t

◆ inj_led_t

◆ inj_state_t

Function Documentation

◆ inj_gesture_name()

◆ injector_host_closed()

◆ injector_init()

◆ injector_input()

◆ injector_led()

◆ injector_poll()

◆ injector_take_attach()

◆ injector_take_reply()

◆ injector_take_wiring()

◆ injector_wiring_done()