advice on running 6 maxbotix ez4 sensors

hi

i am nearing the end of my degree project and i have hit a (hopefully) little problem which i didnt anticipate, mainly due to my lack of knowledge.

i have made a large (3metre x 2 metre) interactive painting which contains 6 maxbotix ez4 sensors spaced about a metre apart.

each sensor goes into an analogue pin on the arduino and from there i pick up the results in maxmsp using the arduino2max code.

they work ok when i run one at a time but when i plug them all in the results go really erratic and pretty unusable. i thought i could sort the problem out with max msp but from doing a bit of research from the maxbotix website it appears that i may need to either reprogram the arduino and/or do some rewiring.

i emailed maxbotix and got a good reply but im a little in the dark about some of the knowhow.

i think i need to have the sensors chained together so they give readings one after another and not all at the same time as they do at the moment. this will involve connecting the tx to the rx of each sensor, which i think i can do.

then the guy from maxbotix said -“Then you must use your uC to bring the first RX high for a short time, (say >20uS but less than 50mS what I have called “strobe”).” which i dont understand but i assume it means i have to put some more code into the arduino. can anyone advise me on this?

i’ll ask him about this tomorrow but i thought i would ask here too so i can get as much advice as possible

-does anyone have any experience with these sensors or similar?

-can anyone give me any advice as regards chaining them together?
(is this necessary or is there another way to get them to give accurate reading when running six at once?)

-can i add extra code to the arduino2max code that will enable me to read the first rx high? or is there another way?

i hope this all makes sense and someone can give me a hand :slight_smile:

many thanks in advance

i think that means you need to connect a digital pin to each rx line. Start out having each digital pin writing output low. then bring one digital high, analog read that sensor's AN pin during some or all of the 50ms then turn that pin back low. repeat with all six sensors and theoretically voila!

read here for more: http://www.maxbotix.com/MaxSonar-EZ1__FAQ.html

thanks for the replies

ive been in contact with maxbotix over the last few days and am in the process of rewiring them now to chain them together so they constantly loop

i think i just have to add a little bit of code into the arduino2max code : can anyone give me a hand with that? :)

thanks again