Embedded Firmware Engineer sollicitatievragen
106
Sollicitatievragen voor Embedded Firmware Engineer gedeeld door sollicitantenMeest gestelde sollicitatievragen
What is ADC ? your experience on ADC? what is ADC resolution? what is I2c, what SPI difference between them.
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I have answered based on hands on experience I had.
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1.analog-to-digital converter 2.We all know it's really hard to get good pricing and cost information. 3.The ADC resolution is defined as the smallest incremental voltage that can be recognized and thus causes a change in the digital output. It is expressed as the number of bits output by the ADC. 4.I2C is half duplex communication and SPI is full duplex communication. ● I2C supports multi master and multi slave and SPI supports single master. ● I2C is a two wire protocol and SPI is a four wire protocol Minder
What techniques would you use to reduce power consumption in an embedded system?
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Sleep modes, reduce refresh operations
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Sleep modes and refresh ops and if you have a fully static design, completely stop the clock. Minder
Describe volatile, const, static keywords. How do you share data between interrupt handler and main thread if you do not have an OS with your embedded controller? How do you optimize linear piecewise function in terms of speed?
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Using (volatile?) global variables.
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Lamport / Bakery , Dekkers, *Petersons* Petersons is the easiest to implement and explain as it only requires 2 flags and 1 int. Minder
What kind of data structure would you use to store data from a serial receive line?
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Another one would be a ring-buffer, which is sort like a queue and easy to implement, especially if you make them a power of two. With either method (queue, ring buffer, etc) you'll need some way to make sure you can tell the transmitting side to stop (XON/XOFF or RTS/CTS) Minder
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A queue (First in, First out [FIFO] )
Describe the two different uses of the "volatile" keywork in C.
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It's to inform compiler that the variable may be altered runtime by another process. This is actually pretty useful in debugging using ICD, you can modify volatile variables and the new value will be used in execution in the instruction that's following your modification. Minder
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One is to turn off compiler optimaztions that remove loops with global variables. Minder
Explain the difference between UART and USART.
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UART - Asynchronous - Clock generated internally, no separate clock line, needs start and stop bit for sync, baud rate mismatch possible. USART - Synchronous - Separate clock line, Doesn't need start, stop bit Minder
Can you connect a 3.3V UART directly with a 5V UART ?
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No, it will damage the 3.3V UART pins and possibly the entire uC. Exception is when the uC datasheet specifically states that those pins are 5V tolerant. Minder
How does it work a mimic wheel (or a similar name for a motor control technique)?
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I'm not a Robotic or Control Engineer so I didn't know the answer, tried to show my logical reasoning. Minder
1) Swap MSB with LSB of 16bit No 2) related to CV 3) integer Overflow 4) bits logic 5) storage classes, volatile etc Don't remember exactly. But most of them from C, data types, bits, embedded.
1 antwoorden↳
I answered pretty well all the questions except for one two
What is the most interesting thing you have done?
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I couldn't answer that question because I have done a lot of interesting things. I also felt it was an immature and irrelevant question, like something a high school student would ask. There were other, even worse questions. Minder