![]() ![]() To keep it short, a buffer is like a waiting queue with a limited capacity. The “classic technique” for arduino serial forgot one important thing: the limited serial buffer size on the Arduino. For example, if you send the number 32768 (which is 2¹⁵) as a string, you need to send 5 bytes (5 characters or 5*8=40 bits) instead of 2 bytes!īut the main issue is not there. With the previous technique, you can only send one byte a time - values in the range - so you may end up sending strings instead, which is quite inefficient. ![]() a count of wheel rotations to estimate a relative position) to a remote computer. Let’s say that instead of sending just a “GO_FORWARD” command, you want to send a speed value (between 0 and 100, 100 representing the max speed), or send encoders value (i.e. This becomes clearly unmaintainable and error prone when the number of possible orders grows, or when you want to interface with different programming languages. You have to make sure that at every place, where you want to read or send a command, the same character is used. So, what’s wrong with the previous technique? A lot of things !įirst, there is a lack of readability: looking at the code, you have to understand that the character ‘a’ corresponds to the order of going forward. You may have the intuition that if we want to do something more complex, we are going to quickly reach the limits of that technique. That works, sure, but that is not very handy. The Arduino code that listens to the computer may look like that: The computer needs to communicate with the Arduino to adjust the motor commands (should we go left/right? should we stop/go forward?) This computer is connected to an Arduino board that sends order to the motors (direction and speed). a Raspberry Pi) connected to a camera and that does all the image processing and time-consuming computation. We assume we have an on-board computer (e.g. Let’s take the example of an autonomous car. Another approach for debugging is to use the Serial.println() method, that permits to write strings. The common approach with the Arduino Serial, is to send characters only, that is to say, send one byte (or 8 bits) at a time, because Serial.write()only allows to do that.
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