--[[ @module max31856 @summary max31856 热电偶温度检测 @version 1.0 @date 2024.06.17 @author Dozingfiretruck @usage --注意:因使用了sys.wait()所有api需要在协程中使用 --注意:ads1115的配置需按照项目需求配置,您需要按照配置寄存器说明重新配置 ADS1115_CONF_HCMD 和 ADS1115_CONF_LCMD !!! -- 用法实例 max31856 = require("max31856") sys.taskInit(function() max31856_spi_device = spi.deviceSetup(1,pin.PB11,1,1,8,5*1000*1000,spi.MSB,1,0) max31856.init(max31856_spi_device) while 1 do local cj_temp = max31856.read_cj_temp() if cj_temp then log.info("max31856 cj_temp: ", cj_temp) end local tc_temp = max31856.read_tc_temp() if tc_temp then log.info("max31856 tc_temp: ", tc_temp) end log.info("max31856 fault: ", max31856.read_fault()) sys.wait(1000) end end) ]] --[[ Register Memory Map ADDRESS READ/WRITE NAME FACTORY FUNCTION DEFAULT 00h/80h Read/Write CR0 00h Configuration 0 Register 01h/81h Read/Write CR1 03h Configuration 1 Register 02h/82h Read/Write MASK FFh Fault Mask Register 03h/83h Read/Write CJHF 7Fh Cold-Junction High Fault Threshold 04h/84h Read/Write CJLF C0h Cold-Junction Low Fault Threshold 05h/85h Read/Write LTHFTH 7Fh Linearized Temperature High Fault Threshold MSB 06h/86h Read/Write LTHFTL FFh Linearized Temperature High Fault Threshold LSB 07h/87h Read/Write LTLFTH 80h Linearized Temperature Low Fault Threshold MSB 08h/88h Read/Write LTLFTL 00h Linearized Temperature Low Fault Threshold LSB 09h/89h Read/Write CJTO 00h Cold-Junction Temperature Offset Register 0Ah/8Ah Read/Write CJTH 00h Cold-Junction Temperature Register, MSB 0Bh/8Bh Read/Write CJTL 00h Cold-Junction Temperature Register, LSB 0Ch Read Only LTCBH 00h Linearized TC Temperature, Byte 2 0Dh Read Only LTCBM 00h Linearized TC Temperature, Byte 1 0Eh Read Only LTCBL 00h Linearized TC Temperature, Byte 0 0Fh Read Only SR 00h Fault Status Register ]] local max31856 = {} local sys = require "sys" max31856.TCTYPE_B = 0x00 -- 类型B max31856.TCTYPE_E = 0x01 -- 类型E max31856.TCTYPE_J = 0x02 -- 类型J max31856.TCTYPE_K = 0x03 -- 类型K max31856.TCTYPE_N = 0x04 -- 类型N max31856.TCTYPE_R = 0x05 -- 类型R max31856.TCTYPE_S = 0x06 -- 类型S max31856.TCTYPE_T = 0x07 -- 类型T max31856.ONESHOT = 0x00 -- 单次转换模式 max31856.CONTINUOUS = 0x01 -- 自动转换模式 max31856.SAMPLE1 = 0x00 -- 1个样品 max31856.SAMPLE2 = 0x01 -- 2个样品 max31856.SAMPLE4 = 0x02 -- 4个样品 max31856.SAMPLE8 = 0x03 -- 8个样品 max31856.SAMPLE16 = 0x04 -- 16个样品 local MAX31856_CR0_REG = 0x00 -- 配置寄存器0 local MAX31856_CR1_REG = 0x01 -- 配置寄存器1 local MAX31856_MASK_REG = 0x02 -- 故障屏蔽寄存器 local MAX31856_CJHF_REG = 0x03 -- 冷端上限故障 local MAX31856_CJLF_REG = 0x04 -- 冷接下限故障 local MAX31856_LTHFTH_REG = 0x05 -- 线性化温度上限故障 MSB local MAX31856_LTHFTL_REG = 0x06 -- 线性化温度上限故障 LSB local MAX31856_LTLFTH_REG = 0x07 -- 线性化温度下限故障 MSB local MAX31856_LTLFTL_REG = 0x08 -- 线性化温度下限故障 LSB local MAX31856_CJTO_REG = 0x09 -- 冷端温度偏移寄存器 local MAX31856_CJTH_REG = 0x0A -- 冷端温度寄存器 MSB local MAX31856_CJTL_REG = 0x0B -- 冷端温度寄存器 LSB local MAX31856_LTCBH_REG = 0x0C -- 线性化TC温度，字节2 local MAX31856_LTCBM_REG = 0x0D -- 线性化TC温度，字节1 local MAX31856_LTCBL_REG = 0x0E -- 线性化TC温度，字节0 local MAX31856_SR_REG = 0x0F -- 故障状态寄存器 local max31856_spi_device local max31856_conversion_mode local max31856_sample_mode local function max31856_write_cmd(reg, data) -- log.info("max31856_write_cmd "..(reg|0x80).." "..data) max31856_spi_device:send({reg|0x80, data}) end local function max31856_read_cmd(reg) local data = max31856_spi_device:transfer(string.char(reg)) -- log.info("max31856_read_cmd "..reg.." "..data:byte()) return data:byte() end local function trigger_oneshot() local cr0 = max31856_read_cmd(MAX31856_CR0_REG) cr0 = cr0&(~0x80) cr0 = cr0|0x40 max31856_write_cmd(MAX31856_CR0_REG, cr0) end local function oneshot_conversion_complete() return (max31856_read_cmd(MAX31856_CR0_REG) & 0x40) == 0 end --[[ 设置热电偶类型 @api max31856.set_tc_type(type) @number type max31856.TCTYPE_B max31856.TCTYPE_E max31856.TCTYPE_J max31856.TCTYPE_K max31856.TCTYPE_N max31856.TCTYPE_R max31856.TCTYPE_S max31856.TCTYPE_T @usage max31856.set_tc_type(max31856.TCTYPE_K) -- 设置类型为K ]] function max31856.set_tc_type(type) local cr1 = max31856_read_cmd(MAX31856_CR1_REG) cr1 = cr1&0xF0 max31856_write_cmd(MAX31856_CR1_REG, cr1|type) end --[[ 设置热电偶电压转换平均模式 @api max31856.set_avgsel(sample_count) @number sample_count max31856.SAMPLE1 max31856.SAMPLE2 max31856.SAMPLE4 max31856.SAMPLE8 max31856.SAMPLE16 @usage max31856.set_avgsel(max31856.SAMPLE1) -- 设置平均模式为1个样品 ]] function max31856.set_avgsel(sample_count) max31856_sample_mode = sample_count local cr1 = max31856_read_cmd(MAX31856_CR1_REG) max31856_write_cmd(MAX31856_CR1_REG, cr1|(sample_count<<4)) end --[[ 设置转化模式 @api max31856.set_cmode(type) @number type max31856.ONESHOT max31856.CONTINUOUS @usage max31856.set_cmode(max31856.ONESHOT) -- 设置转化模式为单次转换 ]] function max31856.set_cmode(type) max31856_conversion_mode = type local cr0 = max31856_read_cmd(MAX31856_CR0_REG) if type == max31856.ONESHOT then cr0 = cr0&(~0x80) cr0 = cr0|0x40 else cr0 = cr0|0x80 cr0 = cr0&(~0x40) end max31856_write_cmd(MAX31856_CR0_REG, cr0) end --[[ 读取错误码 @api max31856.read_fault() @return number 错误码 @usage local fault = max31856.read_fault() ]] function max31856.read_fault() return max31856_read_cmd(MAX31856_SR_REG) end --[[ 读取冷端温度 @api max31856.read_cj_temp() @return number 冷端温度 @usage local cj_temp = max31856.read_cj_temp() ]] function max31856.read_cj_temp() if max31856_conversion_mode == max31856.ONESHOT then trigger_oneshot() sys.wait(145+(max31856_sample_mode-1)*33) local wait = 20 while oneshot_conversion_complete() == false do sys.wait(10) wait = wait - 1 if wait == 0 then return end end end local CJTH = max31856_read_cmd(MAX31856_CJTH_REG) local CJTL = max31856_read_cmd(MAX31856_CJTL_REG) return ((CJTH<<8)|CJTL) / 256.0 end --[[ 读取tc温度 @api max31856.read_tc_temp() @return number tc温度 @usage local tc_temp = max31856.read_tc_temp() ]] function max31856.read_tc_temp() if max31856_conversion_mode == max31856.ONESHOT then trigger_oneshot() sys.wait(145+(max31856_sample_mode-1)*33) local wait = 20 while oneshot_conversion_complete() == false do sys.wait(10) wait = wait - 1 if wait == 0 then return end end end local LTCBH = max31856_read_cmd(MAX31856_LTCBH_REG) local LTCBM = max31856_read_cmd(MAX31856_LTCBM_REG) local LTCBL = max31856_read_cmd(MAX31856_LTCBL_REG) local temp24 = (LTCBH<<16)|(LTCBM<<8)|LTCBL if temp24 & 0x800000 ~= 0 then temp24 = temp24 | 0xFF000000 end temp24 = temp24 >> 5 return temp24 * 0.0078125 end --[[ max31856 初始化 @api max31856.init(spi_device) @userdata spi_device spi设备句柄 @return boolean 初始化成功返回true @usage max31856.init(spi_device) ]] function max31856.init(spi_device) if type(spi_device) ~= "userdata" then return end max31856_spi_device = spi_device max31856_write_cmd(MAX31856_MASK_REG, 0x00) -- 断言所有错误 max31856_write_cmd(MAX31856_CR0_REG, 0x10) -- 开启开路故障检测 max31856_write_cmd(MAX31856_CJTO_REG, 0x00) -- 冷端温度偏移设置为零 max31856.set_tc_type(max31856.TCTYPE_K) -- 设置类型为K max31856.set_cmode(max31856.ONESHOT) -- 设置转化模式为单次转换 max31856.set_avgsel(max31856.SAMPLE1) -- 设置平均模式为1个样品 return true end return max31856