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new i2c protocol

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This commit is contained in:
Olaf Rempel 2007-09-24 19:43:10 +02:00
parent eea082635e
commit 9b486c68e2
1 changed files with 54 additions and 37 deletions
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91
i2c-slave.c
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@ -25,60 +25,74 @@
extern struct blmc_ blmc;
#define CMD_NONE 0x00
#define CMD_SETPWM 0x10
#define CMD_GETSTAT 0x20
#define CMD_REBOOT 0x80
#define CMD_WAIT 0x00
#define CMD_GET_INFO 0x10
#define CMD_SET_PWM 0x21
#define CMD_GET_STATUS 0x22
// #define CMD_SET_PARAM 0x23
// #define CMD_GET_PARAM 0x24
#define CMD_BOOT_LOADER 0x2F
const static uint8_t info[16] = "blctrl m8-v1.0";
ISR(TWI_vect)
{
static uint8_t cmd = CMD_NONE;
static uint8_t cmd;
static uint8_t bcnt;
switch (TWSR & 0xF8) {
/* SLA + W received, ACK returned -> receive Data and ACK */
case 0x60:
cmd = CMD_NONE;
bcnt = 0;
TWCR |= (1<<TWINT) | (1<<TWEA);
break;
/* prev. SLA + W, data received, ACK returned -> receive Data and ACK */
case 0x80:
switch (cmd & 0xF0) {
/* First bytes -> Command */
case CMD_NONE:
if (bcnt == 0) {
cmd = TWDR;
break;
/* set pwm */
case CMD_SETPWM:
setpwm(TWDR);
cmd = CMD_NONE;
break;
/* set parameters */
case CMD_REBOOT:
if (TWDR == 0x42)
switch (cmd) {
case CMD_BOOT_LOADER:
wdt_enable(WDTO_15MS);
cmd = CMD_NONE;
break;
/* rest invalid */
default:
cmd = CMD_NONE;
break;
case CMD_GET_INFO:
case CMD_SET_PWM:
case CMD_GET_STATUS:
bcnt++;
break;
default:
cmd = CMD_WAIT;
bcnt = 0;
break;
}
} else if (bcnt == 1) {
if (cmd == CMD_SET_PWM)
setpwm(TWDR);
bcnt = 0;
} else {
bcnt = 0;
}
TWCR |= (1<<TWINT);
TWCR |= (1<<TWINT) | (1<<TWEA);
break;
/* SLA+R received, ACK returned -> send data */
case 0xA8:
bcnt = 0;
/* prev. SLA+R, data sent, ACK returned -> send data */
case 0xB8:
switch (cmd & 0xF0) {
/* get Current */
case CMD_GETSTAT:
switch (cmd++ & 0x0F) {
switch (cmd) {
case CMD_GET_INFO:
TWDR = info[bcnt++];
bcnt %= sizeof(info);
break;
case CMD_GET_STATUS:
switch (bcnt++) {
case 0: TWDR = blmc.pwm - blmc.pwm_limit;
break;
@ -101,18 +115,21 @@ ISR(TWI_vect)
break;
case 7: TWDR = (blmc.voltage & 0xFF);
cmd = CMD_NONE;
bcnt = 0;
break;
default:
bcnt = 0;
break;
}
break;
/* rest invalid */
default:
cmd = CMD_NONE;
TWDR = 0xFF;
break;
}
TWCR |= (1<<TWINT);
TWCR |= (1<<TWINT) | (1<<TWEA);
break;
/* STOP or repeated START */
@ -122,8 +139,8 @@ ISR(TWI_vect)
TWCR |= (1<<TWINT) | (1<<TWEA);
break;
/* Illegal state -> reset Hardware */
case 0xF8:
/* failsave -> reset Hardware */
default:
TWCR |= (1<<TWINT) | (1<<TWSTO) | (1<<TWEA);
break;
}