Kazuki Yamamoto
UART to I2C master(s) converter, targetting to emulate SC18IM700(NXP) chip
UART to I2C master(s) converter, targetting to emulate SC18IM700(NXP) chip
Features
up to 4x I2C master
- for LPC824 implement, we can use up to 4 channels of I2C masters
- 1x Fm+ and 3x Fm I2C channels
- for LPC1768 implement, we can use up to 2 channels of I2C masters
- 2x Fm I2C channels
- for LPC11U35 implement, only one channel for I2C master,
but program uses USB CDC class for UART communication (means no external USB-Serial converter chip)
- 1x Fm+ I2C channels
1x SPI master
up to 2x 8bit GPIO
Tested Platforms
LPC824
- https://developer.mbed.org/platforms/Switch-Science-mbed-LPC824/
- https://developer.mbed.org/platforms/LPCXpresso824-MAX/
LPC1768
LPC11U35
Quote:
LPC11U35 implement requires importing USBDevice library to use USBSerial class
visit https://github.com/K4zuki/tinyI2C for more information
main.cpp
- Committer:
- K4zuki
- Date:
- 2016-08-31
- Revision:
- 76:fcbc456010e0
- Parent:
- 42:da85c17ea495
File content as of revision 76:fcbc456010e0:
/** uart_i2c_conv for LPC824
*/
#include "mbed.h"
#include "settings.h"
//Table 3. ASCII commands supported by SC18IM700
//ASCII command Hex value Command function
//[X] S 0x53 I2C-bus START
//[X] P 0x50 I2C/SPI-bus STOP
//[X] R 0x52 read SC18IM700 internal register
//[X] W 0x57 write to SC18IM700 internal register
//[?] I 0x49 read GPIO port
//[?] O 0x4F write to GPIO port
//[_] Z 0x5A power down
//[X] C 0x43 change channel
//[_] E 0x45 SPI transfer start
//[_] V 0x__ enable VDDIO output to chip
/**
"C| '0'| P"
"C| '1'| P"
"C| '2'| P"
"C| '3'| P"
"S| 0x_8 _0| 0x_0 _4| 0x_D _E _A _D _B _E _A _F| P"
"S| 0x_8 _0| 0x_0 _4| 0x_D _E _A _D _B _E _A _F| S| 0x_8 _1| 0x_0 _4| P"
"S| 0x_8 _1| 0x_0 _4| P"
"R| '0'| P"
"R| '0'| '1'| ...| P"
"W| '0' 0x_a _a| P"
"W| '0' 0x_a _a| '1' 0x_b _b| ...| P"
"I| '0'| P"
"O| '0'| 0x_a _a| P"
"E| 0x_0 _4| 0x_0 _0| 0x_D _E _A _D _B _E _A _F| P" //write
"E| 0x_0 _4| 0x_0 _4| 0x_D _E _A _D _B _E _A _F| P" //write and read
*/
int main()
{
I2C* dev = &dev1;
#ifdef isUART
pc.baud(115200);
#endif
_spi.frequency(8000000);
bool s = false;
dev1.frequency(400000);//800k; works around 940kHz with 200ohm pullups/ not work at 1M?
#if defined(TARGET_SSCI824) || defined(TARGET_LP824MAX)
dev1.frequency(800000);//800k; works around 940kHz with 200ohm pullups/ not work at 1M?
LPC_IOCON->PIO0_11 &= ~(0x03<<8);
LPC_IOCON->PIO0_11 |= (0x02<<8);
LPC_IOCON->PIO0_10 &= ~(0x03<<8);
LPC_IOCON->PIO0_10 |= (0x02<<8);
#elif defined(TARGET_MCU_LPC11U35_501) || defined(TARGET_LPC11U35_401)
dev1.frequency(800000);//800k; works around 940kHz with 200ohm pullups/ not work at 1M?
LPC_IOCON->PIO0_4 &= ~(0x03<<8);
LPC_IOCON->PIO0_4 |= (0x02<<8);
LPC_IOCON->PIO0_5 &= ~(0x03<<8);
LPC_IOCON->PIO0_5 |= (0x02<<8);
#endif
#ifdef isI2C2
dev2.frequency(400000);//400k
#endif
#ifdef isI2C3
dev3.frequency(400000);//400k
#endif
#ifdef isI2C4
dev4.frequency(400000);//400k
#endif
#ifdef isGPIO1
DigitalInOut* gpio1[] = {
&_GPIO10,
&_GPIO11,
&_GPIO12,
&_GPIO13,
&_GPIO14,
&_GPIO15,
&_GPIO16,
&_GPIO17,
};
for(int k = 0; k < 8; k++){
gpio1[k]->input();
gpio1[k]->mode( PullUp );
}
#endif
DigitalInOut* gpio0[] = {
&_GPIO00,
&_GPIO01,
&_GPIO02,
&_GPIO03,
&_GPIO04,
&_GPIO05,
&_GPIO06,
&_GPIO07,
};
for(int k = 0; k < 8; k++){
gpio0[k]->input();
gpio0[k]->mode( PullUp );
}
int ack = 0;
int plength = 0;
int recieve[256];
char send[256];
for(int k = 0; k < 256; k+=4){
// cafe moca
recieve[k+0] = send[k+0] = 0xC4;
recieve[k+1] = send[k+1] = 0xFE;
recieve[k+2] = send[k+2] = 0xE0;
recieve[k+3] = send[k+3] = 0xCA;
}
int read = 0;
int address = 0;
int data = 0;
int _data = 0;
int length = 0;
int channel = 0;
int format = 8;
int enabled = 0;
int disabled = 0;
enum command_e {
CMD_S='S',
CMD_P='P',
CMD_C='C',
CMD_R='R',
CMD_W='W',
CMD_I='I',
CMD_O='O',
CMD_E='E',
};
enum channel_e {
CH0 = '0',
CH1 = '1',
CH2 = '2',
CH3 = '3',
};
enum register_e {
CHIP_ID = '0',
GPIO0_STAT = '1',
GPIO1_STAT = '2',
GPIO0_CONF = '3',
GPIO1_CONF = '4',
I2C_CONF = '5',
SPI_CONF = '6',
REG7,
REG8,
REG9,
};
// enum chipID_e {
// ID_LPC824 = '0',
// ID_LPC1768 = '1',
// ID_LPC11UXX = '2',
// };
// static const uint8_t chip_id=ID_LPC824;
static uint8_t registers[]={
chip_id,
0x00,
0x00,
0x00,
0x00,
0xFF,
0x70,
REG7,
REG8,
REG9,
};
int i=0;
while(1) {
i=0;
length=0;
while(true) {
read = pc.getc();
recieve[i] = read;
i++;
if(read == 'P') {
plength = i;
break;
}
}
i=0;
while(i < plength) {
switch(recieve[i]) {
case CMD_C:
{
s = false;
channel=recieve[i+1];
switch(channel) {
case CH0:
{
channel = CH0;
dev = &dev1;
break;
}
#ifdef isI2C2
case CH1:
{
channel = CH1;
dev = &dev2;
break;
}
#endif
#ifdef isI2C3
case CH2:
{
channel = CH2;
dev = &dev3;
break;
}
#endif
#ifdef isI2C4
case CH3:
{
channel = CH3;
dev = &dev4;
break;
}
#endif
default:
{
channel = CH0;
dev = &dev1;
break;
}
}
i += 2;
break;
}
case CMD_S:
{
s = true;
ack = plength - 2 - (i+1) + (recieve[i+2] & 0x01);
if(ack >= 4){ //valid packet
address = 0xff & (recieve[i+1] << 4 | (recieve[i+2] & 0x0F));
length = 0xff & (recieve[i+3] << 4 | (recieve[i+4] & 0x0F));
if(address & 0x01) { //read
ack = dev->read(address, send, length, false); //added
send[length] = ack;
length += 1;
i += 5;
} else { // write
for(int j = 0; j < (length * 2); j+=2) {
ack = 0xff&((recieve[5+j] << 4) | (recieve[6+j] & 0x0F));
*(send+(j/2)) = ack; //added
}
ack = dev->write(address, send, length, true); //added
i += (5 + length * 2);
send[0] = ack;
length = 1;
}
}else{
pc.printf("bad packet! %d, %d, %02X, %d\n\r",plength,i,recieve[(i+2)]&0x0F,ack);
s = false;
i = plength;
}
break;
}
case CMD_P:
{
if(s){
dev->stop();
s = false;
if(send[length-1] == 0){
pc.printf("ACK,");
}else{
pc.printf("NAK,");
}
length--;
}
i = plength;
for(int j=0; j<length; j++) {
pc.printf("%02X,",send[j]);
}
pc.printf("ok\n\r");
break;
}
case CMD_R:
{
s = false;
length = plength - 2;
if(length < 1){
pc.printf("bad packet! %d\n\r",length);
i = plength + 1;
length = 0;
}else{
for(int j = 0; j < length; j++){
address = recieve[i+1+j];
switch(address){
case CHIP_ID:
{
data = chip_id;
break;
}
case GPIO0_STAT:
{
for(int k = 0; k < 8; k++){
_data = gpio0[k]->read();
data |= (_data << k);
}
registers[GPIO0_STAT-'0'] = data;
break;
}
case GPIO0_CONF:
{
data = registers[GPIO0_CONF-'0'];
break;
}
#ifdef isGPIO1
case GPIO1_STAT:
{
for(int k = 0; k < 8; k++){
_data = gpio1[k]->read();
data |= (_data << k);
}
registers[GPIO1_STAT-'0'] = data;
break;
}
case GPIO1_CONF:
{
data = registers[GPIO1_CONF-'0'];
break;
}
#endif
case I2C_CONF:
{
data = registers[I2C_CONF-'0'];
break;
}
case SPI_CONF:
{
data = registers[SPI_CONF-'0'];
break;
}
default:
{
data = 0xAA;
break;
}
}
send[j] = (char)data;
data = 0;
}
i += (length+1);
}
break;
}
case CMD_W:
{
s = false;
length = plength - 2;
if(length < 3){
pc.printf("bad packet! %d\n\r",length);
i = plength + 1;
length = 0;
}else{
for(int j = 0; j < length; j +=3){
address = recieve[i+1+j];
data = 0xff & (recieve[i+2+j] << 4 | (recieve[i+3+j] & 0x0F));
_data = 0;
switch(address){
case CHIP_ID:
{
//READ ONLY: do nothing
data = registers[CHIP_ID-'0'];
break;
}
case GPIO0_STAT:
{
_data = registers[GPIO0_CONF-'0'];
for(int k=0; k<8; k++){
if(_data&0x01){ // output
gpio0[k]->write((data>>k)&0x01);
}else{ // input
; // do nothing
}
_data >>= 1;
}
break;
}
case GPIO0_CONF:
{
registers[GPIO0_CONF-'0'] = data;
for(int k = 0; k < 8; k++){
if(data & 0x01){//output
gpio0[k]->output();
}else{//input
gpio0[k]->input();
gpio0[k]->mode(PullUp);
}
data >>= 1;
}
data = registers[GPIO0_CONF-'0'];
break;
}
#ifdef isGPIO1
case GPIO1_STAT:
{
_data = registers[GPIO1_CONF-'0'];
for(int k = 0; k < 8; k++){
if(_data & 0x01){ // output
gpio1[k]->write((data>>k)&0x01);
}else{ // input
; // do nothing
}
_data >>= 1;
}
break;
}
case GPIO1_CONF:
{
registers[GPIO1_CONF-'0'] = data;
for(int k = 0; k < 6; k++){
if(data & 0x01){//output
gpio1[k]->output();
}else{//input
gpio1[k]->input();
gpio1[k]->mode(PullUp);
}
data >>= 1;
}
data = registers[GPIO1_CONF-'0'];
break;
}
#endif
case I2C_CONF:
{
registers[I2C_CONF-'0'] = data;
#if defined(TARGET_LPC1768)
dev1.frequency(100000 * ((0x03 & (data >> 6)) + 1));
#else
dev1.frequency(200000 * ((0x03 & (data >> 6)) + 1));
#endif
#ifdef isI2C2
dev2.frequency(100000 * ((0x03 & (data >> 4)) + 1));
#endif
#ifdef isI2C3
dev3.frequency(100000 * ((0x03 & (data >> 2)) + 1));
#endif
#ifdef isI2C4
dev4.frequency(100000 * ((0x03 & (data >> 0)) + 1));
#endif
break;
}
case SPI_CONF:
{
registers[SPI_CONF-'0'] = data;
format = ((data & 0x04) + 4) << 1;
_spi.format(format, 0x03 & (data));
_spi.frequency(1000000 * ((0x07 & (data >> 4)) + 1));
enabled = (data & 0x08) >> 3;
/*
7 not used
6:4 frequency
3 CE pol
2 word size(0=8bit,1=16bit)
1:0 pol(corresponds to spi.format())
*/
disabled = ~enabled;
break;
}
default:
{
break;
}
}
send[j/3] = data;
}
i += (length + 1);
length /= 3;
}
break;
}
case CMD_I:
{
s = false;
length = plength - 2;
if(length < 1){
pc.printf("bad packet! %d\n\r",length);
i = plength + 1;
length = 0;
}else{
for(int j=0; j<length; j++){
address = recieve[i+1+j];
_data=0;
switch(address){
case GPIO0_STAT:
{
for(int k=0; k<8; k++){
_data = gpio0[k]->read();
data |= (_data << k);
}
registers[GPIO0_STAT-'0'] = data;
break;
}
#ifdef isGPIO1
case GPIO1_STAT:
{
for(int k=0; k<8; k++){
_data = gpio1[k]->read();
data |= (_data << k);
}
registers[GPIO1_STAT-'0'] = data;
break;
}
#endif
default:
{
data = 0xAA;
break;
}
}
send[j] = (char)data;
data = 0;
}
i += (length+1);
}
break;
}
case CMD_O:
{
s = false;
length = plength - 2;
if(length < 3){
pc.printf("bad packet! %d\n\r",length);
i = plength + 1;
length = 0;
}else{
for(int j=0; j<length; j+=3){
address = recieve[i+1+j];
data = 0xff & (recieve[i+2+j] << 4 | (recieve[i+3+j] & 0x0F));
switch(address){
case GPIO0_STAT:
{
_data = registers[GPIO0_CONF-'0'];
for(int k=0; k<8; k++){
if(_data&0x01){ // output
gpio0[k]->write(data&0x01);
}else{ // input
; // do nothing
}
data >>= 1;
_data >>= 1;
}
break;
}
#ifdef isGPIO1
case GPIO1_STAT:
{
_data = registers[GPIO1_CONF-'0'];
for(int k=0; k<8; k++){
if(_data&0x01){ // output
gpio1[k]->write(data&0x01);
}else{ // input
; // do nothing
}
data >>= 1;
_data >>= 1;
}
break;
}
#endif
default:
{
break;
}
}
send[j/3] = data;
}
}
i += (length+1);
length /= 3;
// pc.printf("command O is not implemented, ");
break;
}
case CMD_E:
{
s = false;
/*
"0| 1 2| 3 4| 5 6 7 8 9 10 11 12|13" //plength=14
"E| 0x_0 _1| 0x_0 _0| 0x_D _E| P" //minimum plength=8
"E| 0x_0 _1| 0x_0 _0| 0x_D _E|_A _D| P" //minimum plength=10(16bit)
"E| 0x_0 _4| 0x_0 _0| 0x_D _E _A _D _B _E _A _F| P" //write
"E| 0x_0 _4| 0x_0 _4| 0x_D _E _A _D _B _E _A _F| P" //write and read
*/
length = plength - 2; //6
if(length < 6){
pc.printf("bad packet! %d\n\r",length);
i = plength + 1;
length = 0;
}else{
length = length-4; //actual data in packet
data = 0xff & ((recieve[i+1]<<4) | (recieve[i+2]&0x0F)); // write length
read = 0xff & ((recieve[i+3]<<4) | (recieve[i+4]&0x0F)); // read length
switch(format){
case 8:
{
_cs.write(enabled);
for(int j = 0; j < length; j += 2){
_data = 0xff & ((recieve[i+5+j+0]<<4) | (recieve[i+5+j+1]&0x0F));
ack = _spi.write(_data);
// pc.printf("s%02X,",_data);
send[j/2] = ack;
}
for(int j = length; j < (length+2*read); j+=2){
ack = _spi.write(0xAA); //dummy data to write
// pc.printf("a%02X,",ack);
send[j/2] = ack;
}
_cs.write(disabled);
break;
}
case 16:
{
if((data%2) || (read%2)){ //invalid
pc.printf("bad packet! %d, %d\n\r",data,read);
i = plength + 1;
length = 0;
}else{
_cs.write(enabled);
for(int j = 0; j < length; j += 4){
_data = 0xffff & (((recieve[i+5+j+0] & 0x0F)<<12)|
((recieve[i+5+j+1] & 0x0F)<<8 )|
((recieve[i+5+j+2] & 0x0F)<<4 )|
((recieve[i+5+j+3] & 0x0F)<<0 )
);
ack = _spi.write(_data);
// pc.printf("s%04X,",_data);
send[(j/2)+0] = 0xFF & (ack>>8);
send[(j/2)+1] = 0xFF & (ack>>0);
}
for(int j = length; j < (length+2*read); j += 4){
ack = _spi.write(0xAAAA); //dummy data to write
// pc.printf("a%04X,",ack);
send[(j/2)+0] = 0xFF & (ack>>8);
send[(j/2)+1] = 0xFF & (ack>>0);
}
_cs.write(disabled);
}
break;
}
default:
{
pc.printf("this shold not happen %d\n\r",format);
break;
}
}
// pc.printf("command E is for SPI transmission\n\r");
length = read + data;
i = (plength-1);
}
break;
}
case 'Z':
{
s = false;
pc.printf("command Z is not implemented\n\r");
i=plength;
break;
}
case 'V':
{
s = false;
pc.printf("command V is not implemented\n\r");
i=plength;
break;
}
default:
{
s = false;
pc.printf("command %c is not implemented\n\r", recieve[i]);
i=plength;
break;
}
}
}
i=0;
length=0;
}
}