diff --git a/app/modules/hx711.c b/app/modules/hx711.c index cd871504..61198e33 100644 --- a/app/modules/hx711.c +++ b/app/modules/hx711.c @@ -3,313 +3,65 @@ #include "module.h" #include "lauxlib.h" -#include "lmem.h" #include "platform.h" #include #include #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); + clk_pin = luaL_checkinteger(L,1); + data_pin = luaL_checkinteger(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; +static int ICACHE_FLASH_ATTR hx711_read(lua_State* L) { + uint32_t i; + int32_t data = 0; //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); + 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) { - return luaL_error( L, "ADC timeout!"); - } - - data = read_sample(mode); + //wait for data ready. or time out. + //TODO: set pin inturrupt and come back to it. This may take up to 1/10 sec + // or maybe just make an async version too and have both available. + system_soft_wdt_feed(); //clear WDT... this may take a while. + for (i = 0; i=HX711_MAX_WAIT) { + return luaL_error( L, "ADC timeout!", ( unsigned )0 ); + } + + for (i = 0; i<24 ; i++){ //clock in the 24 bits + platform_gpio_write(clk_pin,1); + platform_gpio_write(clk_pin,0); + data = data<<1; + if (platform_gpio_read(data_pin)==1) { + data = i==0 ? -1 : data|1; //signextend the first bit + } + } + //add 25th clock pulse to prevent protocol error (probably not needed + // since we'll go to sleep immediately after and reset on wakeup.) + platform_gpio_write(clk_pin,1); + platform_gpio_write(clk_pin,0); + //sleep + platform_gpio_write(clk_pin,1); + lua_pushinteger( L, data ); return 1; } @@ -317,20 +69,11 @@ static int hx711_read(lua_State* L) { 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 + // TODO: Make sure that the GPIO system is initialized return 0; } diff --git a/docs/modules/hx711.md b/docs/modules/hx711.md index 1095ebae..0eaa3cff 100644 --- a/docs/modules/hx711.md +++ b/docs/modules/hx711.md @@ -2,11 +2,8 @@ | Since | Origin / Contributor | Maintainer | Source | | :----- | :-------------------- | :---------- | :------ | | 2015-10-09 | [Chris Takahashi](https://github.com/christakahashi) | [Chris Takahashi](https://github.com/christakahashi) | [hx711.c](../../app/modules/hx711.c)| -| 2019-04-20 | [Philip Gladstone](https://github.com/pjsg) | [Philip Gladstone](https://github.com/pjsg) -This module provides access to an [HX711 load cell amplifier/ADC](https://learn.sparkfun.com/tutorials/load-cell-amplifier-hx711-breakout-hookup-guide). The HX711 is an inexpensive 24bit ADC with programmable 128x, 64x, and 32x gain. The standard Chinese sources have [cheap HX711 boards](https://www.aliexpress.com/wholesale?SearchText=hx711+module) for around $1. - -This can be used for single shot reads, or repetitive reads. +This module provides access to an [HX711 load cell amplifier/ADC](https://learn.sparkfun.com/tutorials/load-cell-amplifier-hx711-breakout-hookup-guide). The HX711 is an inexpensive 24bit ADC with programmable 128x, 64x, and 32x gain. Currently only channel A at 128x gain is supported. Note: To save ROM image space, this module is not compiled into the firmware by default. @@ -38,13 +35,11 @@ Read digital loadcell ADC value. `hx711.read(mode)` #### Parameters -- `mode` ADC mode. This parameter specifies which input and the gain to apply to that input. Reading in mode 1 or 2 takes longer than reading in mode 0. +`mode` ADC mode. This parameter is currently ignored and reserved to ensure backward compatibility if support for additional modes is added. Currently only channel A @ 128 gain is supported. |mode | channel | gain | |-----|---------|------| | 0 | A | 128 | -| 1 | B | 32 | -| 2 | A | 64 | #### Returns a number (24 bit signed ADC value extended to the machine int size) @@ -54,54 +49,3 @@ a number (24 bit signed ADC value extended to the machine int size) -- Read ch A with 128 gain. raw_data = hx711.read(0) ``` - -## hx711.start() - -Starts to read multiple samples from the ADC. - -#### Syntax -`hx711.start(mode, samples, callback)` - -#### Parameters -- `mode` ADC mode. This parameter is currently ignored and reserved to ensure backward compatibility if support for additional modes is added. -- `samples` The number of samples before the callback is invoked. The length of time depends on the chip's sampling rate. -- `callback` The callback is invoked with three arguments (see below). - -|mode | channel | gain | -|-----|---------|------| -| 0 | A | 128 | -| 1 | B | 32 | -| 2 | A | 64 | - -#### Returns -nothing - -#### Callback -This is invoked every time `samples` samples are read from the HX711. The arguments are: - -- A string which contains `samples` packed 24 bit values. This can be unpacked with the `struct` module (using the "i3" format). -- The time in microseconds of the reception of the last sample in the buffer. -- The number of samples dropped before the start of this buffer (after the end of the previous buffer). - -#### Notes -This api only is built if GPIO_INTERRUPT_ENABLE and GPIO_INTERRUPT_HOOK_ENABLE are defined in the -`user_config.h`. This is the default. - -Also, do not try and mix calls to `start` and calls to `read`. Any calls to `read` will implicitly call `stop` first. - -#### Example -```lua --- Read ch A with 128 gain. -hx711.start(0, 2, function(s, t, d) local r1, r2, _ = struct.unpack("i3 i3", s) print(r1, r2) end) -``` - -## hx711.stop() - -Stops a previously started set of reads. Any data in buffers is lost. No more callbacks will be invoked. - -#### Syntax -`hx711.stop()` - -#### Returns -nothing -