338 lines
8.2 KiB
C
338 lines
8.2 KiB
C
// Module for HX711 load cell amplifier
|
|
// https://learn.sparkfun.com/tutorials/load-cell-amplifier-hx711-breakout-hookup-guide
|
|
|
|
#include "module.h"
|
|
#include "lauxlib.h"
|
|
#include "lmem.h"
|
|
#include "platform.h"
|
|
#include <stdlib.h>
|
|
#include <string.h>
|
|
#include "user_interface.h"
|
|
static uint8_t data_pin;
|
|
static uint8_t clk_pin;
|
|
// The fields below are after the pin_num conversion
|
|
static uint8_t pin_data_pin;
|
|
static uint8_t pin_clk_pin;
|
|
|
|
#ifdef GPIO_INTERRUPT_ENABLE
|
|
static task_handle_t tasknumber;
|
|
|
|
// HX711_STATUS can be defined to enable the hx711.status() function to get debug info
|
|
#undef HX711_STATUS
|
|
#define BUFFERS 2
|
|
|
|
typedef struct {
|
|
char *buf[BUFFERS];
|
|
uint32_t dropped[BUFFERS];
|
|
uint32_t timestamp[BUFFERS];
|
|
uint32_t interrupts;
|
|
uint32_t hx711_interrupts;
|
|
uint16_t buflen;
|
|
uint16_t used;
|
|
uint32_t nobuffer;
|
|
uint8_t active; // slot of the active buffer
|
|
uint8_t freed; // slot of the most recently freed buffer
|
|
uint8_t mode;
|
|
uint8_t dropping; // is non zero when there is no space
|
|
int cb_ref;
|
|
} CONTROL;
|
|
|
|
static CONTROL *control;
|
|
#endif
|
|
|
|
/*Lua: hx711.init(clk_pin,data_pin)*/
|
|
static int hx711_init(lua_State* L) {
|
|
clk_pin = luaL_checkint(L,1);
|
|
data_pin = luaL_checkint(L,2);
|
|
MOD_CHECK_ID( gpio, clk_pin );
|
|
MOD_CHECK_ID( gpio, data_pin );
|
|
|
|
platform_gpio_mode(clk_pin, PLATFORM_GPIO_OUTPUT, PLATFORM_GPIO_FLOAT);
|
|
platform_gpio_mode(data_pin, PLATFORM_GPIO_INPUT, PLATFORM_GPIO_FLOAT);
|
|
platform_gpio_write(clk_pin,1);//put chip to sleep.
|
|
|
|
pin_data_pin = pin_num[data_pin];
|
|
pin_clk_pin = pin_num[clk_pin];
|
|
return 0;
|
|
}
|
|
|
|
static int32_t ICACHE_RAM_ATTR read_sample(char mode) {
|
|
int i;
|
|
int32_t data = 0;
|
|
|
|
for (i = 0; i < 24 ; i++){ //clock in the 24 bits
|
|
GPIO_REG_WRITE(GPIO_OUT_W1TS_ADDRESS, 1 << pin_clk_pin);
|
|
GPIO_REG_WRITE(GPIO_OUT_W1TC_ADDRESS, 1 << pin_clk_pin);
|
|
data = data << 1;
|
|
if (GPIO_REG_READ(GPIO_IN_ADDRESS) & (1 << pin_data_pin)) {
|
|
data = i == 0 ? -1 : data | 1; //signextend the first bit
|
|
}
|
|
}
|
|
//add 25th-27th clock pulse to prevent protocol error
|
|
for (i = 0; i <= mode; i++) {
|
|
GPIO_REG_WRITE(GPIO_OUT_W1TS_ADDRESS, 1 << pin_clk_pin);
|
|
GPIO_REG_WRITE(GPIO_OUT_W1TC_ADDRESS, 1 << pin_clk_pin);
|
|
}
|
|
|
|
return data;
|
|
}
|
|
|
|
#ifdef GPIO_INTERRUPT_ENABLE
|
|
static void ICACHE_RAM_ATTR hx711_data_available() {
|
|
if (!control) {
|
|
return;
|
|
}
|
|
uint32_t bits = GPIO_REG_READ(GPIO_IN_ADDRESS);
|
|
if (bits & (1 << pin_data_pin)) {
|
|
return; // not ready
|
|
}
|
|
|
|
// Read a sample
|
|
int32_t data = read_sample(control->mode);
|
|
|
|
if (control->dropping) {
|
|
if (control->active == control->freed) {
|
|
// still can't advance
|
|
control->nobuffer++;
|
|
return;
|
|
}
|
|
// Advance
|
|
control->active = (1 + control->active) % BUFFERS;
|
|
control->dropping = 0;
|
|
}
|
|
|
|
// insert into the active buffer
|
|
char *dest = control->buf[control->active] + control->used;
|
|
*dest++ = data;
|
|
*dest++ = data >> 8;
|
|
*dest++ = data >> 16;
|
|
|
|
control->used += 3;
|
|
if (control->used == control->buflen) {
|
|
control->used = 0;
|
|
control->timestamp[control->active] = system_get_time();
|
|
control->dropped[control->active] = control->nobuffer;
|
|
control->nobuffer = 0;
|
|
// post task
|
|
task_post_medium(tasknumber, control->active);
|
|
|
|
uint8_t next_active = (1 + control->active) % BUFFERS;
|
|
|
|
if (control->active == control->freed) {
|
|
// We can't advance to the buffer
|
|
control->dropping = 1;
|
|
} else {
|
|
// flip to other buffer
|
|
control->active = next_active;
|
|
}
|
|
}
|
|
}
|
|
|
|
static uint32_t ICACHE_RAM_ATTR hx711_interrupt(uint32_t ret_gpio_status)
|
|
{
|
|
// This function really is running at interrupt level with everything
|
|
// else masked off. It should take as little time as necessary.
|
|
//
|
|
//
|
|
|
|
// This gets the set of pins which have changed status
|
|
uint32 gpio_status = GPIO_REG_READ(GPIO_STATUS_ADDRESS);
|
|
|
|
int pin_mask = 1 << pin_data_pin;
|
|
int i;
|
|
|
|
control->interrupts++;
|
|
|
|
if (gpio_status & pin_mask) {
|
|
uint32_t bits = GPIO_REG_READ(GPIO_IN_ADDRESS);
|
|
control->hx711_interrupts++;
|
|
if (!(bits & pin_mask)) {
|
|
// is now ready to read
|
|
hx711_data_available();
|
|
}
|
|
GPIO_REG_WRITE(GPIO_STATUS_W1TC_ADDRESS, gpio_status & pin_mask);
|
|
}
|
|
|
|
return gpio_status & ~pin_mask;
|
|
}
|
|
|
|
// Lua: hx711.start( mode, samples, callback )
|
|
static int hx711_start( lua_State* L )
|
|
{
|
|
uint32_t mode = luaL_checkint( L, 1 );
|
|
uint32_t samples = luaL_checkint( L, 2 );
|
|
|
|
if (mode > 2) {
|
|
return luaL_argerror( L, 1, "Mode value out of range" );
|
|
}
|
|
|
|
if (!samples || samples > 400) {
|
|
return luaL_argerror( L, 2, "Samples value out of range (1-400)" );
|
|
}
|
|
|
|
if (control) {
|
|
return luaL_error( L, "Already running" );
|
|
}
|
|
|
|
int buflen = 3 * samples;
|
|
|
|
control = (CONTROL *) luaM_malloc(L, sizeof(CONTROL) + BUFFERS * buflen);
|
|
if (!control) {
|
|
return luaL_error( L, "Failed to allocate memory" );
|
|
}
|
|
|
|
int cb_ref;
|
|
|
|
if (lua_type(L, 3) == LUA_TFUNCTION || lua_type(L, 3) == LUA_TLIGHTFUNCTION) {
|
|
lua_pushvalue(L, 3); // copy argument (func) to the top of stack
|
|
cb_ref = luaL_ref(L, LUA_REGISTRYINDEX);
|
|
} else {
|
|
luaM_free(L, control);
|
|
control = NULL;
|
|
return luaL_argerror( L, 3, "Not a callback function" );
|
|
}
|
|
|
|
memset(control, 0, sizeof(*control));
|
|
control->buf[0] = (char *) (control + 1);
|
|
control->buflen = buflen;
|
|
int i;
|
|
|
|
for (i = 1; i < BUFFERS; i++) {
|
|
control->buf[i] = control->buf[i - 1] + buflen;
|
|
}
|
|
control->mode = mode;
|
|
control->cb_ref = cb_ref;
|
|
control->freed = BUFFERS - 1;
|
|
|
|
// configure data_pin as interrupt input
|
|
platform_gpio_register_intr_hook(1 << pin_data_pin, hx711_interrupt);
|
|
platform_gpio_mode(data_pin, PLATFORM_GPIO_INT, PLATFORM_GPIO_FLOAT);
|
|
platform_gpio_intr_init(data_pin, GPIO_PIN_INTR_NEGEDGE);
|
|
|
|
|
|
// Wake up chip
|
|
platform_gpio_write(clk_pin, 0);
|
|
|
|
return 0;
|
|
}
|
|
|
|
// Lua: hx711.stop( )
|
|
static int hx711_stop( lua_State* L )
|
|
{
|
|
if (control) {
|
|
platform_gpio_mode(data_pin, PLATFORM_GPIO_INPUT, PLATFORM_GPIO_FLOAT);
|
|
CONTROL *to_free = control;
|
|
control = NULL;
|
|
luaL_unref(L, LUA_REGISTRYINDEX, to_free->cb_ref);
|
|
luaM_free(L, to_free);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int hx711_status( lua_State* L )
|
|
{
|
|
if (control) {
|
|
lua_pushlstring(L, (char *) control, sizeof(*control));
|
|
return 1;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void hx711_task(os_param_t param, uint8_t prio)
|
|
{
|
|
(void) prio;
|
|
if (!control) {
|
|
return;
|
|
}
|
|
|
|
lua_State *L = lua_getstate();
|
|
|
|
if (control->cb_ref != LUA_NOREF) {
|
|
lua_rawgeti(L, LUA_REGISTRYINDEX, control->cb_ref);
|
|
|
|
lua_pushlstring(L, control->buf[param], control->buflen);
|
|
lua_pushinteger(L, control->timestamp[param]);
|
|
lua_pushinteger(L, control->dropped[param]);
|
|
|
|
control->freed = param;
|
|
|
|
lua_call(L, 3, 0);
|
|
}
|
|
}
|
|
#endif
|
|
|
|
#define HX711_MAX_WAIT 1000000
|
|
/*will only read chA@128gain*/
|
|
/*Lua: result = hx711.read()*/
|
|
static int hx711_read(lua_State* L) {
|
|
int j;
|
|
//TODO: double check init has happened first.
|
|
//
|
|
|
|
uint32_t mode = luaL_optinteger(L, 1, 0);
|
|
|
|
if (mode > 2) {
|
|
return luaL_argerror( L, 1, "Mode value out of range" );
|
|
}
|
|
|
|
#ifdef GPIO_INTERRUPT_ENABLE
|
|
if (control) {
|
|
hx711_stop(L);
|
|
}
|
|
#endif
|
|
|
|
//wakeup hx711
|
|
platform_gpio_write(clk_pin, 0);
|
|
|
|
int32_t data;
|
|
|
|
// read two samples if mode > 0. We discard the first read and return the
|
|
// second value.
|
|
for (j = (mode ? 1 : 0); j >= 0; j--) {
|
|
uint32_t i;
|
|
|
|
//wait for data ready. or time out.
|
|
system_soft_wdt_feed(); //clear WDT... this may take a while.
|
|
for (i = 0; i<HX711_MAX_WAIT && platform_gpio_read(data_pin)==1;i++){
|
|
asm ("nop");
|
|
}
|
|
|
|
//Handle timeout error
|
|
if (i >= HX711_MAX_WAIT) {
|
|
return luaL_error( L, "ADC timeout!");
|
|
}
|
|
|
|
data = read_sample(mode);
|
|
}
|
|
|
|
//sleep -- unfortunately, this resets the mode to 0
|
|
platform_gpio_write(clk_pin, 1);
|
|
lua_pushinteger(L, data);
|
|
return 1;
|
|
}
|
|
|
|
// Module function map
|
|
LROT_BEGIN(hx711)
|
|
LROT_FUNCENTRY( init, hx711_init )
|
|
LROT_FUNCENTRY( read, hx711_read )
|
|
#ifdef GPIO_INTERRUPT_ENABLE
|
|
LROT_FUNCENTRY( start, hx711_start )
|
|
#ifdef HX711_STATUS
|
|
LROT_FUNCENTRY( status, hx711_status )
|
|
#endif
|
|
LROT_FUNCENTRY( stop, hx711_stop )
|
|
#endif
|
|
LROT_END( hx711, NULL, 0 )
|
|
|
|
|
|
int luaopen_hx711(lua_State *L) {
|
|
#ifdef GPIO_INTERRUPT_ENABLE
|
|
tasknumber = task_get_id(hx711_task);
|
|
#endif
|
|
return 0;
|
|
}
|
|
|
|
NODEMCU_MODULE(HX711, "hx711", hx711, luaopen_hx711);
|