[问答]

8位控制器能否正常与8位SPI模式的L9942通信？

问答对人有帮助，内容完整，我也想知道答案 0 亲爱的专家，我是L9942驱动IC的新手。我目前正致力于该IC用于汽车安全应用中的步进电机控制。我附上了一个用于与L9942进行SPI通信的'c'程序。我使用的控制器是一个8位控制器。以下是其他细节：控制器：PIC 16F877ASPI用于8位模式（仅8位可用）SPI通信的模式0用于通信的波特率为3Mhz（对此有疑问）L9942的16位寄存器值在两个8位整数变量中初始化后这些变量（两个8位变量）一个接一个地发送，使CSN连续保持低电平。所有8个寄存器都遵循相同的顺序。程序的顺序如下所示，用于编程所有8个寄存器。保持CSN高初始将CSN转换为低转发第一个8位（MSB优先）转移第二个8位（MSB优先）将CSN推送到高位以下内容不明白：有时输出电压波形（电机输出）平稳且电机正常运行，但有时电机没有响应，有时波形也不规则。当STEP频率增加或减少时，电机启动移动。 SPI通信是否不正确？8位控制器能否正常与8位SPI模式的L9942通信？通信的波特率应该是多少？我理解，如果一旦加载了所有8个寄存器值，L9942将负责驱动具有正确STEP输入的电机..是否正确？我理解，当必须改变方向时，只需重新加载第一个寄存器，将程序计数器位保持为0 ......是否正确？停止阈值设置为8位（D0至D7）。根据数据表，间隔为16us。所以它只能有2 ^ 8 = 256，因此255X16us = 4080us。 4080us可以设置的最大阈值时间是什么？Stall位何时设置？在我的情况下，我使用的是线性执行器。因此，当它达到线性极限位置的末端时，电机仍会尝试移动，但线性滑块不会移动。这会设置失速位吗？请参考我附带的c程序并帮助我。问候， M.Siva #spi #spi＃l9942＃l9942 以上来自于谷歌翻译以下为原文 Dear Experts, I am new to L9942 Driver IC. I am currently working on this IC for a stepper motor control in automotive safety application. I have attached a 'c' program written for SPI communication with L9942. The controller which I am using is a 8 bit controller. The following are the other details: Controller: PIC 16F877A SPI is used in 8 bit mode (only 8 bit is possible) Mode 0 of SPI communication is used Baud rate for communication is 3Mhz (doubtful about this) The 16 bit register values of L9942 are initialized in two 8bit integer variables Later these variables (two 8bit variables) are sent one after the other keeping the CSN low consecutively. The same is followed for all 8 registers. The sequence of the program goes like this for programming all 8 registers. Keep CSN High initially Pull CSN to Low Transfer the first 8bit (MSB first) Transfer the second 8bit (MSB first) Push CSN to High The following are not understood: Sometimes the output voltage waveform (the output to the motors) is smooth and the motor runs properly, but sometimes there is no response from motor and also at times the waveform is irregular. At times when the STEP frequency is increased or decreased the motor starts moving. Is the SPI communication improper? Can an 8bit Controller properly communicate with L9942 with 8bit SPI mode? What should be the baud rate of communication? I have an understanding that, if once all the 8 register values are loaded, L9942 will take care of driving the motor with a proper STEP input.. is it correct? I have an understanding that, only the first register has to be reloaded when the direction has to be changed, keeping the program counter bits to 0... is it correct? There are 8 bits for Stall threshold setting (D0 to D7). As per the datasheet the interval is 16us. So can it only have 2^8=256, therefore 255X16us which = 4080us. So is 4080us the maximum threshold time that can be set? When does Stall bit set? In my case I am using a Linear actuator. So when it reaches end of position in linear limit, the motor still tries to move but the linear slider does not move. Will this set the stall bit? Please refer to my attached c program also and help me out. Regards, M.Siva #spi #spi #l9942 #l9942 0
2019-1-25 15:26:36　　评论淘帖0 邀请回答您可以邀请以下用户，快速回答问题 × wang21cj 该类别下有 44 个回答。邀请回答新星之火12138 该类别下有 41 个回答。邀请回答 chm5 该类别下有 39 个回答。邀请回答 hgimtk 该类别下有 33 个回答。邀请回答 HengDu 该类别下有 30 个回答。邀请回答 hwp0415229 该类别下有 28 个回答。邀请回答 jghgfdssas 该类别下有 28 个回答。邀请回答可口可甜该类别下有 26 个回答。邀请回答 kingnet6688 该类别下有 26 个回答。邀请回答颜刚YanG 该类别下有 26 个回答。邀请回答 zyh34997 该类别下有 25 个回答。邀请回答柱子图宁该类别下有 25 个回答。邀请回答 kingnet9999 该类别下有 25 个回答。邀请回答 jenny042 该类别下有 25 个回答。邀请回答 andyfly7 该类别下有 25 个回答。邀请回答麻酱该类别下有 25 个回答。邀请回答成长的小师弟该类别下有 24 个回答。邀请回答 gXDhn 该类别下有 24 个回答。邀请回答 jiangwenwen 该类别下有 24 个回答。邀请回答哼小曲该类别下有 24 个回答。邀请回答举报李宛蔓相关推荐 • 步进电机运行中各种模式下STEP输入频率与电流斩波的关系 3759 • EVAL-L9942接口问题 1257 • 8位微控制器的多种低功耗模式 2313 • STM8微控制器系列产品 1749 • PIC 16位和32位作为ARM控制器好吗？ 2415 • AD9265使用非SPI控制模式8-11位输出不正常 2501 • MPC5777C可以将SPI模式更改为8位模式吗？ 208 • nrf24l01通信无法进行该怎么办？ 1834 • 如何用8位单片机访问16位的寄存器？ 2239 • 如何调nrf24l01无线2.4g模块stm8s与32通信 1607 2个回答

答案对人有帮助，有参考价值 0 非常感谢您的感谢。目前，步进电机正在向后移动并向前移动。对寄存器0的方向输入变化没有响应，有时它向前移动，有时它向后移动以便在寄存器0输入相同的方向。我也编程了所有寄存器中的当前配置文件值，请查看我的寄存器initialization0b 000 0000010011001 //寄存器0 0b 001 1000000000000 //注册1 0b 010 0011000000010 //注册2 0b 011 1000100001100 //注册3 0b 100 1101000010110 //注册4 0b 101 1111000011101 //注册5 0b 110 0000000011111 //注册6 0b 111 0000000000000 //注册7 还有什么方法可以将电机停在某个位置？要么关闭PWM输入（无论如何电流停留在线圈中）或关闭启用？从L9942 IC接收的故障位有什么用？我没有设定失速的阈值时间，这是电机这种行为的原因吗？ D0到D7阈值采用什么单位或ms或s？请帮我解释一下。提前致谢。问候， M.Siva 以上来自于谷歌翻译以下为原文 Very thankful for your grateful reply. Currently the stepper motor is trying to move backward and moves forward. No response for the change in direction input at register 0, at times it moves forward and at times it moves backward for the same direction input at register 0. Also I have programmed all the current profile values in the registers respectively, please have a look at my register initialization 0b 000 0000010011001 //register 0 0b 001 1000000000000 //register 1 0b 010 0011000000010 //register 2 0b 011 1000100001100 //register 3 0b 100 1101000010110 //register 4 0b 101 1111000011101 //register 5 0b 110 0000000011111 //register 6 0b 111 0000000000000 //register 7 Also what is the proper way to stop the motor at a position? Either to turn OFF PWM input (anyhow current stays in the coil) or turn OFF Enable? What is the use of fault bit which is received at DO from L9942 IC? I have not programmed threshold time for stall, is this a reason for such behavior of motor? What unit does the D0 to D7 threshold value take- us or ms or s? Please do help me in all my clarifications. Thanks in advance. Regards, M.Siva

2019-1-25 15:41:48 评论举报李宛蔓

答案对人有帮助，有参考价值 0 亲爱的先生，感谢您的大力支持。尝试使用AN2650程序设置STALL阈值，当STALL阈值为00000000时未设置STALL，但当值为00000001时，STALL设置。仅仅16us的时间段就设置了失速。 STEP输入频率为400 HZ，使用全步进模式。那么，是否还有其他参数必须注意正确的失速阈值？失速阈值设置是否也应考虑STEP输入频率？对于STEP输入频率的变化，电机不平稳并停止旋转。这是什么原因？对于全步进，电机仅在380到420 Hz之间平滑，并且只有在超过1 KHz时才进行微步进。当参考STEP输入详细信息的数据表时，只给出了所需的最短时间。还有什么需要注意的吗？停止电机的正确方法是什么？是否禁用EN（启用输入）是唯一的方法？提前感谢问候， M.Siva 以上来自于谷歌翻译以下为原文 Dear Sir, Thank You for your great support. Tried to set STALL threshold using the AN2650 procedure, when the STALL threshold value is 00000000 STALL is not set, but when the value is 00000001 the STALL is set. For just a time period of 16us the stall is set. The frequency of STEP input was 400 HZ and Full-Stepping mode was used. So, is there any other parameter which has to be taken care for proper stall threshold? Does stall threshold value setting should also consider the STEP input frequency? For change in STEP input frequency, the motor is not smooth and stops rotating. What is the reason for this? For Full-stepping, the motor is smooth only from 380 to 420 Hz and Micro-stepping does only when there is more than 1 KHz. When referred to the datasheet for STEP input details, only the minimum time period required is given. Is there anything else which should be taken care of? What is the proper way to stop the motor? Is disabling the EN (Enable Input) is the only way? Thanks in advance Regards, M.Siva

2019-1-25 16:33:32 评论举报李宛蔓