Standalone GoodIX GT911 capacitive-touch bring-up demo + HIL (#122). More...

#include <stddef.h>
#include <stdint.h>
#include "ra8_attributes.h"
#include "ra8_board_ek_ra8d2.h"
#include "ra8_board_ek_ra8d2_touch.h"
#include "ra8_boot_entry.h"
#include "ra8_cgc.h"
#include "ra8_err.h"
#include "ra8_isr.h"
#include "ra8_mstp.h"
#include "ra8_time.h"
#include "ra8_touch.h"

Include dependency graph for main.c:

Enumerations
enum	td_consts_t : uint32_t { k_td_uart_baud = 115200U , k_td_max_points = 5U , k_td_poll_max = 20000U , k_td_dec_ten = 10U }
	Console / GT911 / poll knobs (no magic numbers). More...

Functions
static void	internal_td_print (const uint8_t *msg, uint32_t len)
	Emit a byte run on the SCI8 console.
static void	internal_td_panic_halt (const uint8_t *msg, uint32_t len)
	Print the fail banner and trap (ra8_emulator halts on the BKPT).
static void	internal_td_print_uint (uint32_t value)
	Print a small unsigned integer in decimal.
static uint8_t	internal_td_poll_points (uint16_t out_x, uint16_t out_y)
	Poll the GT911 for one touch frame; report the first contact.
static void	internal_td_setup_or_halt (void)
	Bring up clocks/MSTP/time + the SCI8 console; halt on failure.
void	main (void)
	App entry: bring up the GT911, poll a touch frame, print the banner.

Variables
static const uint8_t	s_msg_boot [] = "touch-demo: boot\r\n"
	Startup banner after console initialization.
static const uint8_t	s_msg_fail [] = "touch-demo: FAIL init\r\n"
	Fatal clock, timebase, module, or console setup banner.
static const uint8_t	s_msg_open [] = "touch: FAIL open\r\n"
	Fatal touch-controller open-failure banner.
static const uint8_t	s_msg_pre [] = "touch: open=OK pts="
	Prefix for the successful open and bounded-poll report.
static const uint8_t	s_msg_x [] = " x="
	Label introducing the first contact X coordinate.
static const uint8_t	s_msg_y [] = " y="
	Label introducing the first contact Y coordinate.
static const uint8_t	s_msg_eol [] = "\r\n"
	CRLF terminator for the composed poll report.

Detailed Description

Standalone GoodIX GT911 capacitive-touch bring-up demo + HIL (#122).

ra8_touch (GT911 over IIC_B channel 0) was only ever exercised inside ereader_ui – there was no standalone example and no CI gate for the touch driver itself. This app is that gate: it brings up the GT911 end-to-end (I2C probe + product-id wake), then polls for a touch frame and reports the first decoded contact on the SCI8 J-Link OB console:

touch: open=OK pts=1 x=<X> y=<Y>

The bring-up half (open=OK) is the deterministic, finger-free part of the gate – it proves the real ra8_touch_open -> IIC_B -> GT911 path reached the product-id check. The point half is exercised under ra8_emulator, which models the GT911 on the modelled I2C bus and injects a tap via --click X Y; that tap returns through the genuine ra8_touch_read decode, so the banner carries a real decoded coordinate. On a bare bench with no finger the poll loop times out and reports pts=0, but open=OK still holds – so hil.conf asserts only the bring-up substring, which is stable either way.

[Ring 7 / App] {World: NS}

Copyright: Copyright (c) 2026 Brighton Sikarskie SPDX-License-Identifier: MIT

Since: 0.1.0

Definition in file main.c.

Enumeration Type Documentation

◆ td_consts_t

enum td_consts_t : uint32_t

Console / GT911 / poll knobs (no magic numbers).

Enumerator
k_td_uart_baud	Console baud.
k_td_max_points	Read up to the GT911 capacity.
k_td_poll_max	Bounded poll iterations (NASA R2).
k_td_dec_ten	Decimal radix / small-buf cap.

Definition at line 46 of file main.c.

Function Documentation

◆ internal_td_panic_halt()

void internal_td_panic_halt	(	const uint8_t *	msg,
		uint32_t	len )

static

Print the fail banner and trap (ra8_emulator halts on the BKPT).

Emits the diagnostic once, executes a debugger-visible breakpoint, then enters a permanent low-power wait loop.

Parameters

[in]	msg	Start of the failure banner.
[in]	len	Number of banner bytes to transmit.

Precondition: msg addresses at least len readable bytes.; Console setup progressed far enough to accept diagnostics.

Postcondition: The banner has been offered to the console.; Control never returns to the caller.

Note: The terminal loop preserves peripheral state for inspection.

Since: 0.1.0

Definition at line 140 of file main.c.

References internal_td_print(), and RA8_INTERNAL.

Referenced by internal_td_setup_or_halt(), and main().

◆ internal_td_poll_points()

uint8_t internal_td_poll_points	(	uint16_t *	out_x,
		uint16_t *	out_y )

static

Poll the GT911 for one touch frame; report the first contact.

Calls ra8_touch_read up to k_td_poll_max times (statically bounded). ra8_emulator re-arms an injected --click each SysTick chunk until the firmware drains it, so the loop catches the tap within a few chunks; on a bare bench with no finger it exhausts and reports zero points.

Parameters

[out]	out_x	Receives the first contact's X (0 if none).
[out]	out_y	Receives the first contact's Y (0 if none).

Returns: Number of points seen in the caught frame (0 or >=1).

Return values

0	No usable touch frame arrived within the bounded poll.

Precondition: out_x and out_y are non-NULL writable pointers.; The touch controller has been opened successfully.

Postcondition: Both outputs hold zero when no contact is found.; On success both outputs hold the first decoded contact.

Note: The polling bound prevents an absent operator from hanging the demo.

Since: 0.1.0

Definition at line 198 of file main.c.

References k_ra8_ok, k_td_max_points, k_td_poll_max, RA8_INTERNAL, ra8_touch_read(), ra8_touch_point_t::x, and ra8_touch_point_t::y.

Referenced by main().

◆ internal_td_print()

void internal_td_print	(	const uint8_t *	msg,
		uint32_t	len )

static

Emit a byte run on the SCI8 console.

Passes caller-owned bytes and their explicit length directly to the board console.

Parameters

[in]	msg	Start of the byte run to transmit.
[in]	len	Number of bytes to transmit.

Precondition: msg addresses at least len readable bytes.; The board console is initialized when len is nonzero.

Postcondition: The console has been offered the complete byte run.; No touch-controller state is modified.

Note: Transport status is intentionally ignored by this diagnostic demo.

Since: 0.1.0

Definition at line 122 of file main.c.

References ra8_board_uart_console_write(), and RA8_INTERNAL.

Referenced by internal_td_panic_halt(), internal_td_print_uint(), and main().

◆ internal_td_print_uint()

void internal_td_print_uint ( uint32_t value )

static

Print a small unsigned integer in decimal.

Builds digits in reverse in a fixed local buffer and emits them most-significant first.

Parameters

[in] value Unsigned value to render in base ten.

Precondition: k_td_dec_ten can hold every supported value's digits.; The board console is initialized.

Postcondition: The decimal representation has been offered to the console.; No global touch state is modified.

Note: Output has no prefix, padding, or line ending.

Since: 0.1.0

Definition at line 160 of file main.c.

References internal_td_print(), k_td_dec_ten, and RA8_INTERNAL.

Referenced by main().

◆ internal_td_setup_or_halt()

void internal_td_setup_or_halt ( void )

static

Bring up clocks/MSTP/time + the SCI8 console; halt on failure.

Initializes each prerequisite in dependency order and treats any failure as terminal.

Precondition: Reset startup completed data and BSS initialization.; Board clock registers are in their reset-compatible state.

Postcondition: On return clocks, module-stop control, time, and SCI8 are initialized.; Any failed prerequisite has emitted the setup-failure banner and halted.

Note: Single-shot boot helper; it is not reentrant.

Since: 0.1.0

Definition at line 225 of file main.c.

References internal_td_panic_halt(), k_ra8_clock_id_cpuclk0, k_ra8_ok, k_td_uart_baud, ra8_board_uart_console_init(), ra8_cgc_get_clock_hz(), ra8_cgc_init(), RA8_INTERNAL, ra8_mstp_init(), ra8_time_init(), and s_msg_fail.

Referenced by main().

◆ main()

void main ( void )

App entry: bring up the GT911, poll a touch frame, print the banner.

The application entry point Reset_Handler hands control to.

Precondition: Reset_Handler copied .data and zeroed .bss.; SystemInit set VTOR / FPU / priority grouping.

Postcondition: The open=OK touch banner is emitted; the CPU then loops in WFI.

Since: 0.1.0

Definition at line 250 of file main.c.

References internal_td_panic_halt(), internal_td_poll_points(), internal_td_print(), internal_td_print_uint(), internal_td_setup_or_halt(), k_ra8_ok, k_ra8_touch_irq_pin_unset, k_td_max_points, ra8_board_touch_open(), ra8_isr_globals_enable(), s_msg_boot, s_msg_eol, s_msg_open, s_msg_pre, s_msg_x, and s_msg_y.

Variable Documentation

◆ s_msg_boot

const uint8_t s_msg_boot[] = "touch-demo: boot\r\n"

static

Startup banner after console initialization.

Marks the point before I2C and touch-controller bring-up begins.

Note: Immutable bytes written with an explicit compile-time length.

Since: 0.1.0

Definition at line 60 of file main.c.

◆ s_msg_eol

const uint8_t s_msg_eol[] = "\r\n"

static

CRLF terminator for the composed poll report.

Completes the human-readable result after both coordinates.

Note: Shared only within this translation unit.

Since: 0.1.0

Definition at line 108 of file main.c.

◆ s_msg_fail

const uint8_t s_msg_fail[] = "touch-demo: FAIL init\r\n"

static

Fatal clock, timebase, module, or console setup banner.

Provides the deterministic diagnostic for early boot failure.

Note: Consumed only by the terminal panic path.

Since: 0.1.0

Definition at line 68 of file main.c.

◆ s_msg_open

const uint8_t s_msg_open[] = "touch: FAIL open\r\n"

static

Fatal touch-controller open-failure banner.

Distinguishes GT911/bus failure from earlier platform setup failure.

Note: Consumed only by the terminal panic path.

Since: 0.1.0

Definition at line 76 of file main.c.

Referenced by main().

◆ s_msg_pre

const uint8_t s_msg_pre[] = "touch: open=OK pts="

static

Prefix for the successful open and bounded-poll report.

Followed by the point count and first decoded coordinates.

Note: Contains no line terminator because the report is composed in pieces.

Since: 0.1.0

Definition at line 84 of file main.c.

◆ s_msg_x

const uint8_t s_msg_x[] = " x="

static

Label introducing the first contact X coordinate.

Separates the point count from its horizontal position.

Note: Followed immediately by an unsigned decimal value.

Since: 0.1.0

Definition at line 92 of file main.c.

Referenced by main().

◆ s_msg_y

const uint8_t s_msg_y[] = " y="

static

Label introducing the first contact Y coordinate.

Separates the horizontal and vertical positions.

Note: Followed immediately by an unsigned decimal value.

Since: 0.1.0

Definition at line 100 of file main.c.

Referenced by main().

Enumerations

Functions

Variables

Detailed Description

Enumeration Type Documentation

◆ td_consts_t

Function Documentation

◆ internal_td_panic_halt()

◆ internal_td_poll_points()

◆ internal_td_print()

◆ internal_td_print_uint()

◆ internal_td_setup_or_halt()

◆ main()

Variable Documentation

◆ s_msg_boot

◆ s_msg_eol

◆ s_msg_fail

◆ s_msg_open

◆ s_msg_pre

◆ s_msg_x

◆ s_msg_y