openmv/src/omv/modules/py_lcd_cec.c
2023-09-16 13:24:24 -07:00

557 lines
17 KiB
C

/*
* This file is part of the OpenMV project.
*
* Copyright (c) 2013-2023 Ibrahim Abdelkader <iabdalkader@openmv.io>
* Copyright (c) 2013-2023 Kwabena W. Agyeman <kwagyeman@openmv.io>
*
* This work is licensed under the MIT license, see the file LICENSE for details.
*
* LCD Python module.
*/
#include "py/obj.h"
#include "py/mphal.h"
#include "py/objarray.h"
#include "py/nlr.h"
#include "py/runtime.h"
#include "py_helper.h"
#include "py_lcd_cec.h"
#include "omv_boardconfig.h"
#include "omv_gpio.h"
#if MICROPY_PY_LCD
#ifdef OMV_CEC_PRESENT
static mp_obj_t lcd_cec_user_cb = NULL;
static volatile uint8_t lcd_cec_src_addr = 0;
static volatile mp_obj_t lcd_cec_dst_addr = NULL;
static volatile mp_obj_t lcd_cec_bytes = NULL;
////////////////////////////////////////////////////////////////////////////////
// stsw-stm32086 - https://www.st.com/en/embedded-software/stsw-stm32086.html
////////////////////////////////////////////////////////////////////////////////
/* Start bit timings */
#define Sbit_Nom_LD 37 /* Start Bit Nominal Low duration: 37 x 100µs = 3.7ms */
#define Sbit_Nom_HD 8 /* Start Bit Nominal High Duration: 8 x 100µs = 0.8ms */
#define Sbit_Min_LD 35 /* Start Bit Minimum Low duration: 35 x 100µs = 3.5ms */
#define Sbit_Max_LD 39 /* Start Bit Maximum Low duration: 39 x 100µs = 3.9ms */
#define Sbit_Min_TD 43 /* Start Bit Minimum Total duration: 43 x 100µs = 4.3ms */
#define Sbit_Max_TD 47 /* Start Bit Maximum Total duration: 47 x 100µs = 4.7ms */
/* Data bit logical "0" timings */
#define Dbit0_Nom_LD 15 /* Data Bit "0" Nominal Low duration: 15 x 100µs = 1.5ms */
#define Dbit0_Nom_HD 9 /* Data Bit "0" Nominal High Duration: 9 x 100µs = 0.9ms */
#define Dbit0_Min_LD 13 /* Data Bit "0" Minimum Low duration: 13 x 100µs = 1.3ms */
#define Dbit0_Max_LD 17 /* Data Bit "0" Maximum Low duration: 17 x 100µs = 1.7ms */
/* Data bit logical "1" timings */
#define Dbit1_Nom_LD 6 /* Data Bit (logical "1") Nominal Low duration: 0.6ms */
#define Dbit1_Nom_HD 18 /* Data Bit (logical "1") Nominal High Duration: 1.8ms */
#define Dbit1_Min_LD 4 /* Data Bit "1" Minimum Low duration: 0.4ms */
#define Dbit1_Max_LD 8 /* Data Bit "1" Maximum Low duration: 0.8ms */
/* Data bit duration */
#define DbitX_Min_TD 20 /* Data Bit Minimum Total duration: 2ms */
#define DbitX_Max_TD 27 /* Data Bit Maximum Total duration: 2.7ms */
/* Header or Data block definition */
#define DataBlock 0
#define HeaderBlock 1
/* Masks */
#define ReceiveFrameStatusMask 0x00010000
#define FrameSendToMeMask 0x00020000
#define InitiatorAddressMask 0x000000FF
static uint8_t cec_byte;
static uint8_t cec_bit;
static uint8_t cec_eom;
static uint32_t cec_counter;
static uint8_t cec_last_byte;
static void CEC_Wait100us(uint32_t nTime) {
mp_hal_delay_us(nTime * 100);
}
static void CEC_SendStartBit() {
/* Start Low Period */
omv_gpio_write(OMV_CEC_PIN, 0);
/* Wait 3.7ms*/
CEC_Wait100us(Sbit_Nom_LD);
/* Start High Period */
omv_gpio_write(OMV_CEC_PIN, 1);
/* Wait 0.8ms for a total of 3.7 + 0.8 = 4.5ms */
CEC_Wait100us(Sbit_Nom_HD);
}
static uint8_t CEC_ReceiveStartBit() {
/* Initialize cec_counter */
cec_counter = 0;
/* Go to high impedance: CEC bus state = VDD */
omv_gpio_write(OMV_CEC_PIN, 1);
/* Wait for rising edge of the start bit */
while (!omv_gpio_read(OMV_CEC_PIN)) {
/* Wait 100us */
CEC_Wait100us(1);
/* Increment cec_counter that contains the duration of low level duration */
cec_counter++;
/* If too long low level for start bit */
if (cec_counter > Sbit_Max_LD) {
/* Exit: it's an error: 0 */
return 0;
}
}
/* If too short duration of low level for start bit */
if (cec_counter < Sbit_Min_LD) {
/* Exit: it's an error: 0 */
return 0;
}
/* Wait for falling edge of the start bit (end of start bit) */
while (omv_gpio_read(OMV_CEC_PIN)) {
/* Wait 100us */
CEC_Wait100us(1);
/* Increment cec_counter that contains the duration of high level duration */
cec_counter++;
/* If too long total duration for start bit */
if (cec_counter > Sbit_Max_TD) {
/* Exit: it's an error: 0 */
return 0;
}
}
/* If too short total duration for start bit */
if (cec_counter < Sbit_Min_TD) {
/* Exit: it's an error: 0 */
return 0;
}
/* Exit: start bit received correctly */
return 1;
}
static void CEC_SendDataBit(uint8_t bit) {
/* Start Low Period: the duration depends on the Logical Level "0" or "1" */
omv_gpio_write(OMV_CEC_PIN, 0);
/* Wait 0.6 ms if Logical Level is "1" and 1.5ms if Logical Level is "0" */
CEC_Wait100us(bit ? Dbit1_Nom_LD : Dbit0_Nom_LD);
/* Start High Period: the duration depends on the Logical Level "0" or "1" */
omv_gpio_write(OMV_CEC_PIN, 1);
/* Wait 1.8 ms if Logical Level is "1" and 0.9 ms if Logical Level is "0" */
CEC_Wait100us(bit ? Dbit1_Nom_HD : Dbit0_Nom_HD);
}
static uint8_t CEC_ReceiveDataBit() {
uint8_t bit = 0xFF;
/* Initialize cec_counter */
cec_counter = 0;
/* Wait for rising edge of the data bit */
while (!omv_gpio_read(OMV_CEC_PIN)) {
/* Wait 100us */
CEC_Wait100us(1);
/* Increment cec_counter that contains the duration of low level duration */
cec_counter++;
if (cec_counter > Dbit0_Max_LD) {
/* Exit: it's an error: 0xFF */
return 0xFF;
}
}
/* If the measured duration of the low level is greater than the minimum low duration
of "logical 0" i.e > 1.3 ms */
if (cec_counter > Dbit0_Min_LD) {
/* The received bit is "logical 0" */
bit = 0;
} else {
/* If the measured duration of the low level is greater than the maximum low duration
of "logical 1" i.e > 0.8 ms */
if (cec_counter > Dbit1_Max_LD) {
/* Exit: it's an error: 0xFF */
return 0xFF;
}
/* If the measured duration of the low level is greater than the minimum low duration
of "logical 1" i.e > 0.4 ms */
if (cec_counter > Dbit1_Min_LD) {
/* The received bit is "logical 1" */
bit = 1;
} else {
/* Exit: it's an error: 0xFF */
return 0xFF;
}
}
/* Wait for falling edge of the data bit */
while (omv_gpio_read(OMV_CEC_PIN)) {
/* Wait 100us */
CEC_Wait100us(1);
/* Increment cec_counter that contains the duration of high level duration */
cec_counter++;
/* If too long total duration for the data bit is detected */
if (cec_counter > DbitX_Max_TD) {
/* Exit: it's an error: 0xFF */
return 0xFF;
}
}
/* If too short total duration for the data bit is detected */
if (cec_counter < DbitX_Min_TD) {
/* Exit: it's an error: 0xFF */
return 0xFF;
}
/* The data bit is received correctly. Return its value */
return bit;
}
static void CEC_SendAckBit() {
mp_uint_t start = mp_hal_ticks_ms();
/* Wait for falling edge: end of EOM bit sent by the initiator */
while (omv_gpio_read(OMV_CEC_PIN)) {
if ((mp_hal_ticks_ms() - start) > 10) {
mp_raise_msg(&mp_type_OSError, MP_ERROR_TEXT("Ack timeout!"));
}
}
/* Send ACK bit */
CEC_SendDataBit(0);
/* Force the bus to 0: for ACK bit delimiting */
omv_gpio_write(OMV_CEC_PIN, 0);
/* Wait 100us to allow the initiator to detect the end of ACK bit */
CEC_Wait100us(1);
/* Go to high impedance: CEC bus state = VDD */
omv_gpio_write(OMV_CEC_PIN, 1);
}
static uint8_t CEC_ReceiveAckBit() {
uint8_t AckValue = 0xFF;
/* Get the ACK bit */
AckValue = CEC_ReceiveDataBit();
/* If the byte has been acknowledged by the Follower (ACK = 0) */
if (AckValue != 0xFF) {
mp_uint_t start = mp_hal_ticks_ms();
/* Wait for falling edge of ACK bit (the end of ACK bit)*/
while (omv_gpio_read(OMV_CEC_PIN)) {
if ((mp_hal_ticks_ms() - start) > 10) {
mp_raise_msg(&mp_type_OSError, MP_ERROR_TEXT("Ack timeout!"));
}
}
}
return AckValue;
}
static bool CEC_SendByte(uint8_t byte) {
/* Send the data byte: bit by bit (MSB first) */
for (cec_bit = 0; cec_bit <= 7; cec_bit++) {
CEC_SendDataBit(byte & 0x80);
byte <<= 1;
}
/* Send EOM bit after sending the data byte */
CEC_SendDataBit(cec_last_byte);
/* Force the bus to 0: for EOM bit delimiting */
omv_gpio_write(OMV_CEC_PIN, 0);
/* Wait 100us to allow the follower to detect the end of EOM bit */
CEC_Wait100us(1);
/* Go to high impedance: CEC bus state = VDD */
omv_gpio_write(OMV_CEC_PIN, 1);
/* If the byte is acknowledged by the receiver */
if (CEC_ReceiveAckBit() == 0) {
/* Exit: the data byte has been received by the follower */
return true;
} else {
/* The data byte is not acknowledged by the follower */
/* Exit: the data byte has not been received by the follower */
return false;
}
}
static uint8_t CEC_ReceiveByte(uint8_t HeaderDataIndicator) {
uint8_t TempReceiveBit = 0;
bool ReceiveByteStatus = true;
/* Initialize cec_counter */
cec_byte = 0;
for (cec_bit = 0; cec_bit <= 7; cec_bit++) {
/* Shift the data byte */
cec_byte <<= 1;
/* Receive the data bit */
TempReceiveBit = CEC_ReceiveDataBit();
/* If the received bit was received incorrectly */
if (TempReceiveBit == 0xFF) {
/* If the received bit is wrong */
/* Store the error status */
ReceiveByteStatus = false;
}
/* Build the data byte (MSB first) */
cec_byte |= TempReceiveBit;
}
/* Read EOM bit */
cec_eom = CEC_ReceiveDataBit();
/* If the EOM bit was received incorrectly */
if (cec_eom == 0xFF) {
/* If the received bit is wrong */
/* Store the error status */
ReceiveByteStatus = false;
}
/* If the byte to send is a "Data" block */
if (HeaderDataIndicator == DataBlock) {
/* If the bits has been received correctly, acknowledge the data byte */
if (ReceiveByteStatus != false) {
/* Send the Ack bit */
CEC_SendAckBit();
/* Byte received correctly: return 1 */
return 1;
} else {
/* Otherwise do not acknowledge the received byte */
/* Byte received incorrectly: return 0 */
return 0;
}
} else {
/* If the byte is a "Header" block */
/* If the bits has been received correctly and do not acknowledge the byte */
if (ReceiveByteStatus != false) {
/* Byte received correctly: return 1 */
return 1;
} else {
/* If the bits has been received incorrectly and do not acknowledge the byte */
/* Byte received incorrectly: return 0 */
return 0;
}
}
}
static bool CEC_SendFrame(uint8_t InitiatorAddress, uint8_t FollowerAddress, uint8_t MessageLength, uint8_t *Message) {
uint8_t i = 0;
uint8_t HeaderBlockValueToSend = 0;
cec_last_byte = 0;
/* Build the Header block to send */
HeaderBlockValueToSend = (((InitiatorAddress & 0xF) << 4) | (FollowerAddress & 0xF));
/* Disable EXTI global interrupt to avoid the EXTI to enter EXTI interrupt
while transmitting a frame */
if (lcd_cec_user_cb) {
omv_gpio_irq_enable(OMV_CEC_PIN, false);
}
/* Send start bit */
CEC_SendStartBit();
/* Send initiator and follower addresses. If the Header block is not
transmitted successfully then exit and return error */
if (CEC_SendByte(HeaderBlockValueToSend) == false) {
if (lcd_cec_user_cb) {
omv_gpio_irq_enable(OMV_CEC_PIN, true);
}
/* Exit and return send failed */
return false;
}
/* Send data bytes */
for (i = 0; i < MessageLength; i++) {
if (i == (MessageLength - 1)) {
cec_last_byte = 1;
}
/* Send data byte and check if the follower sent the ACK bit = 0 */
if (CEC_SendByte(Message[i]) == false) {
if (lcd_cec_user_cb) {
omv_gpio_irq_enable(OMV_CEC_PIN, true);
}
/* Exit and return send failed */
return false;
}
}
if (lcd_cec_user_cb) {
omv_gpio_irq_enable(OMV_CEC_PIN, true);
}
/* Exit and return send succeeded */
return true;
}
static uint32_t CEC_ReceiveFrame(uint8_t *Message, uint8_t FollLogAdd) {
uint32_t i = 0;
uint32_t InitiatorAddress = 0;
uint32_t ReceiveStatus = 1;
uint32_t FrameSendToMe = 0;
cec_byte = 0;
cec_eom = 0;
/* If the start bit has been received successfully */
if (CEC_ReceiveStartBit()) {
/* Get the first byte and check if the byte has been received correctly */
if (CEC_ReceiveByte(HeaderBlock)) {
/* Get the initiator address */
InitiatorAddress = cec_byte >> 4;
/* If the frame was sent to me */
if ((cec_byte & 0x0F) == FollLogAdd) {
CEC_SendAckBit(); /* Send Acknowledge bit = 0 */
FrameSendToMe = 1;
/* Continue to read the data byte since the frame is not completed */
while (!cec_eom) {
/* Check if the byte has been received correctly */
if (CEC_ReceiveByte(DataBlock)) {
/* Build the frame */
Message[i] = cec_byte;
i++;
} else {
/* If the byte has not been received correctly */
/* Set receive status bit (Error) */
ReceiveStatus = 0;
}
}
}
}
} else {
/* If the start bit has not been received successfully */
/* Set receive status bit (Error) */
ReceiveStatus = 0;
}
/* Return the different receive infos: Receive status, number of data byte received,
Frame send to me or not and the initiator address */
return ((((InitiatorAddress) | (i << 8)) | (ReceiveStatus << 16)) | (FrameSendToMe << 17));
}
////////////////////////////////////////////////////////////////////////////////
static bool lcd_cec_receive_frame_int(mp_obj_t dst_addr, bool assertOnError) {
mp_obj_array_t *bytes = (mp_obj_array_t *) lcd_cec_bytes;
uint32_t result = CEC_ReceiveFrame(bytes->items, mp_obj_get_int(dst_addr));
bool receiveFrameStatus = result & ReceiveFrameStatusMask;
bool frameSendToMe = result & FrameSendToMeMask;
if (assertOnError && (!receiveFrameStatus)) {
mp_raise_msg(&mp_type_OSError, MP_ERROR_TEXT("Receive Failed!"));
}
if (receiveFrameStatus && frameSendToMe) {
lcd_cec_src_addr = result & InitiatorAddressMask;
bytes->len = (result >> 8) & 0xFF;
return true;
}
return false;
}
void lcd_cec_send_frame(mp_obj_t dst_addr, mp_obj_t src_addr, mp_obj_t bytes) {
size_t len;
uint8_t *data = (uint8_t *) mp_obj_str_get_data(bytes, &len);
if (!CEC_SendFrame(mp_obj_get_int(src_addr), mp_obj_get_int(dst_addr), len, data)) {
mp_raise_msg(&mp_type_OSError, MP_ERROR_TEXT("Send Failed!"));
}
}
mp_obj_t lcd_cec_received_frame_src_addr() {
return mp_obj_new_int(lcd_cec_src_addr);
}
mp_obj_t lcd_cec_received_frame_bytes() {
return lcd_cec_bytes;
}
mp_obj_t lcd_cec_receive_frame(uint n_args, const mp_obj_t *args, mp_map_t *kw_args) {
if (n_args > 0) {
int timeout = py_helper_keyword_int(n_args, args, 1, kw_args, MP_OBJ_NEW_QSTR(MP_QSTR_timeout), 1000);
mp_uint_t start = mp_hal_ticks_ms();
while (omv_gpio_read(OMV_CEC_PIN)) {
if ((mp_hal_ticks_ms() - start) > timeout) {
mp_raise_msg(&mp_type_OSError, MP_ERROR_TEXT("Receive timeout!"));
}
}
return mp_obj_new_bool(lcd_cec_receive_frame_int(args[0], true));
}
mp_raise_msg(&mp_type_OSError, MP_ERROR_TEXT("Expected destination address!"));
}
static void lcd_cec_extint_callback(void *data) {
if (lcd_cec_user_cb && lcd_cec_receive_frame_int(lcd_cec_dst_addr, false)) {
mp_call_function_0(lcd_cec_user_cb);
}
}
void lcd_cec_deinit() {
omv_gpio_irq_enable(OMV_CEC_PIN, false);
lcd_cec_user_cb = NULL;
lcd_cec_src_addr = 0;
lcd_cec_dst_addr = NULL;
lcd_cec_bytes = NULL;
omv_gpio_deinit(OMV_CEC_PIN);
}
void lcd_cec_init() {
omv_gpio_config(OMV_CEC_PIN, OMV_GPIO_MODE_OUTPUT_OD, OMV_GPIO_PULL_NONE, OMV_GPIO_SPEED_LOW, -1);
omv_gpio_write(OMV_CEC_PIN, 1);
mp_hal_delay_ms(1);
lcd_cec_bytes = mp_obj_new_bytearray_by_ref(0, m_new(byte, 16));
omv_gpio_config(OMV_CEC_PIN, OMV_GPIO_MODE_IT_FALL, OMV_GPIO_PULL_UP, OMV_GPIO_SPEED_LOW, -1);
omv_gpio_irq_register(OMV_CEC_PIN, lcd_cec_extint_callback, NULL);
}
void lcd_cec_register_cec_receive_cb(mp_obj_t cb, mp_obj_t dst_addr) {
omv_gpio_irq_enable(OMV_CEC_PIN, false);
lcd_cec_user_cb = cb;
lcd_cec_dst_addr = dst_addr;
if (cb != mp_const_none) {
omv_gpio_irq_enable(OMV_CEC_PIN, true);
}
}
#endif // OMV_CEC_PRESENT
#endif // MICROPY_PY_LCD