Wixel usage doubt


i want to build 2 robots which can send data and recieve data wirelessly

i want to do xactly as in the above video, i think wixel can do that ,
but my doubt is how,because i dont how to interface wixel :frowning: but i know to interface only using arduino environment :slight_smile: (i know arduino language)

1)according to my understanding we need 2 wixel to do this ,i will connect one wixel -> one baby o 328p (this makes the first robot) and another wixel ->another baby o 328p(this is the 2nd robot) i can do the connections based on the documentation provided by pololu, after doing this,i want to send data inputs from bot1->bot2 and also recieve data from bot2…wirelessly ,so how do i do this using wixel since i know to programme only using arduino ,inorder to achieve what i want do i need to learn to programme wixels or there is a easier way…
that is if i run the wireless serial app in both wixels and programme the baby o 328p’s using arduino to send data and recieve data is enough to achieve comunication between the 2 robots…
2)how to pair 2 wixels ,like xbee can be paired by some method …so how do i pair 2 wixels,according to my understanding running the wireless serial app does this(assume 2 wixels using same radio channel).if i have understood something wrongly please point it out…

thank you ,


Yes, you can use Wixels for that application. You would not need to do any Wixel programming. Using the Wireless Serial App you can create a wireless serial connection between the two robots. To pair them, you configure the same radio_channel parameter on both Wixels. The Wixels would be connected to the robot controllers’ serial ports.

- Ryan

thanx for the reply ryan,

i just ordered them today cant wait to recieve them… :smiley:

my final query ,i dont know much about wireless data transmission yet as how that happens and all those interior concepts related ,my question may seem a bit stupid …but i want to clear my doubts so am posting
->actually i am building 2 robots which will be solving a grid but not as the same as in the above video but simultaneously
what i mean to say is one will be the guider bot and it will be followed by the follower bot just behind it at the same time actually not as exact as in the video above…so can the wixel handle that amount of data traffic and do not lose any signal and properly feed them to the controller through its serial ports
at high speed because lots of data inputs will be streaming in every second… :question:

thanx for all the help
and awesome products…

I would expect it to work but I do not know how much data you are intending to send. On the product page, we talk about effective data rates up to 10 KB/s. Note that the data rate is also limited by how fast your code is able to process it.

- Ryan

i dont know how much data would be sent but its like ill be sending letters like "a b c d " every time it enters my arduino conditions
what am planning is sending the line follower inputs from bot1->bot2…wirelessly
that is ill be controlling 2 robots with 1 qtr8a sensor array placed on bot1 for line following the other one will just be moving based on the conditions given in my code and the inputs it recieves wirelessly from bot1
so whats your final thought ,sorry for not giving sufficent data…
is there any way to caluclate how many bytes of data is sent by looking into my code

thanx ryan,

ok according to my application its like
example:-ill be wirelessly reading 1qtr8a sensor arrays inputs data from wixel1 controller number - 1 ---------->arduinos serial monitor
on my computer using another wixel which recieves this and is connected to controller number -2 which will help me connect to the computer inorder to access serial monitor(arduino).
so if it can display the readings properly than i think my project does not include data traffic more than that…
so keeping the above scenario do you think its capable…

thanx ryan,

You are saying you only have a QTR sensor array on the front robot, right? I don’t think that will have much chance of working because you would not be able to do position feedback on the second robot.

- Ryan

yes i will be using only one qtr8a sensor array whose inputs will drive the first robot as well as the second robot so i want the wixel to transmit the readings wirelessly so that the follower bot moves exactly as the guider bot
ok if that is not possible then is there any other way to achieve what i want to do using wixel like how do i restrict the data traffic …
ill not be transmitting the 8 independent sensor readings but only the position calulated in the first bot so the job of the second bot is to react accordingly based on the position value it recieves…the code in the second bot will differ very much because ill only call the serial.available function() in arduino and assign the recieved data to a variable called ‘a’

a = serial.available();

and based on this i will give output conditions in the second bot
i want this project to be done so please suggest me the ways i have already ordered wixel and dont have money to get the required hardware so i have toachieve this using wixel only.
so please suggest how to do this by intelligent coding…

thanx for the reply,

My reason for saying it will not work does not have anything to do with using the Wixel for communication. The sensor values or read-line value will not be of much use to the second bot because it is not mechanically linked to the sensor, so the readings will not help it follow a line or navigate. It might work for very short distance, but the errors will build up quickly and the second robot will soon not be following the actual line. My suggestion would be add line sensors to the second robot. If you cannot do that, then you need to come up with some other way for the second robot to accurately navigate.

- Ryan

thanx ryan,

now i got to know the exact problem,yes your right ill be doing a grid solver with 2 seperate qtr8a sensors onboard and yes i got you it’ll not help me navigate in the exact same fashion,theres a competition in my college where the problem statement is to build a robot which can guide the second robot wirelessly with the inputs the first robot gets so the job of the first robot is to just follow a simple track(black line on white background) and the job of the second robot is to just move in the same way the first robot moves there will be no track involved in case of the second robot …so the second robot has to just move like the first robot without a line being involved in this case…which will be placed at a distance of 5 feet from the first robot and simply has to move on the floor …
do you think this is possible…


That is a hard problem. Adding a QTR sensor array to the second robot is pointless if there is no line for it to follow. Typically robots doing this kind of precise positioning rely on fixed reference beacons in a room, or, on a larger scale, GPS. I think you might be able to get close by using encoders but even that might not be enough to do it well. You will have to calibrate both robot’s software so that they both consider the same movements to be equivalent.

- Ryan

thanx for the reply ryan,

but in this competition the accuracy is measured by lighting leds on the second robot when the first robot passes a check point and since there will be no lines involved incase of second robot there
will be markers which the second robot has to pass through these markers are black strips which are 10cm long
the arena for the second robot to complete will be like the one in the picture below
so the job of second robot is to just pass on those black markers without moving out of the box and light leds whenever the first robot passes a check point on its track so overall that much accuracy is not required …so if second bot can navigate on those black markers without going out of the arena and just light an led when the first robot passes a check point in its arena(black line on white background )…
i think its sufficent …
so if i use the xact same hardware on both the bots(motors with same rpm),and batteries with same voltage rating can i complete the task…i know that voltage variation will not be same so …i have to do some intelligent coding based on the tests on this …
so if wixel can transmitt the signals of the sensor readings from the first bot ,ill some how get it working the way i want the second robot to perform …ill be using wireless serial app for data transmission …so is the app capable of transmitting a caluclated position value of qtr8a sensor array and transmitt this to the wixel on the second robot…
so whats your final thought can wixel transmitt the sensor readings efficiently …if it can do this then my job is 50%easy…

ashwin j,

I think it is likely that you will run into a limit of your sensors before you run into a limit of the Wixel.

- Ryan

thanx fr the reply,

i didnt understand this sentence …am sorry for it…i have a difficulty to understand american accent a bit…so a bit elaborate answer would help me understand better …
please bear with me…
thank u for your patient replies… :smiley:

ashwin j

Let me try again:

The capability of your sensors will most likely be what limits the performance of your robot system, not the capabilities of the Wixel.

- Ryan

thanx a lot for your reply

ok now ill just conduct some basic tests with wixel to achieve this ,once am ready with my results ill come back and post queries…

yes now am clear about wixel

so u mean to say that i need a good code and hardware synchronization to achieve what i want to…
the fact that i am using only 1 qtr8a sensors makes the process difficult…