Resolved by Dunning-Kruger!
I recently purchased a EZ4 board and I was anxious to use it. I went through two cables (mini din to molex) both of them traced correctly but yet I got nothing when I went into ARC.
The camera functioned (although it appears to only take up half the image window), I could connect to the web server no problem, but not the Roomba (although it acted like it wanted to connect).
In your pin out you have two pins being used one is ground and one is sending 5 volts (pin 3) to the create. Which confuses me because the directions make note to measure the voltage coming from the cable however I believe pin 3 SENDS to the Roomba not receives, am I misunderstanding?
My last attempt I took a PS2 cable put a meter lead on the pins you mentioned and then on the bare wire, until I had a complete connection. I attached those two to a molex connector with servo wire double checked the connections and still nada.
Help? stress tired
Thanks Richard that script did the trick. I found the init command on the original script was wrong and locking up the EZ-B. After changing the init command in your original script the everything works great.
This is all with the same cable that does not wok on port D0. I think this then is confirmation that the Roomba Movement Panel that is in ARC simply does not work (at least with the hardware I have).
Hopefully I can save the custom Movement Panel and make it work with the other controls the way it is demonstrated on the video. If not, the main reason that sold me on purchasing the EZ-B is removed.
Does anyone know if ARC is open source? I didn't see it on GitHub.
@todd85.... Awesome.... Now the fun begins.... I'll look at my sample project and change it as required...
Cheers Richard
See the items in the black menu bar on the software page: http://synthiam.com/Products/ARC
Alan
Hello,
It looks like the specs for the roomba serial port are 0-5 volts. If port d0 is only ouputting 0-3.3 volts the communication could be intermittent. Seems you could put a 3.3 volt to 5 volt converter between d0 port and roomba receive pin. Let me know if this could be the issue? Could be a simple fix.....Rick B.
@rbonari, incorrect. Google says: http://www.irobot.com/~/media/MainSite/PDFs/About/STEM/Create/Create_2_Serial_to_33V_Logic.pdf
DJ,
The link from I-Robot states that the Create 2 serial port uses 5 VOLT LOGIC LEVELS for asynchronous serial communications.
It also states that Create 2 can take a 3.3 Voltage level on its rx and dd lines.
This does not mean that 3.3 volts is the ideal level that the rx line wants to see. It may work but some of the people who are having issues with the D0 port on the Roomba and Create robots could be having their issues because the receive level the robots want to see is closer to 5 volts.
I have worked as a senior electronics and engineering technician and I have seen many instances where although the spec is 0-5 volts or whatever it may be, that when you lower the voltage from the spec that all bets are off. This leads to unreliable flaky operation sometimes.
All i-robot says is that it can take 3.3 volts. They don't state that it is the ideal level. I have seen specs on their site stating the levels are 0-5 volts.
For those people having issues with d0 port connected to roomba or create, they could try a similar circuit to what is in the link you sent me to translate the d0 output of 3.3 volts to 5 volts for the roomba and create rx line. They also make translator IC's that do the translation in both directions. I believe adafruit sells them and they are pretty cheap.
what levels do the ez-bv4 uart channels put out as people seem to have more reliable communications using them.
I understand your point too, but there is a reason voltage specs are given. Would be interesting to see what I-Robot engineers have to say about this issue with regards to the 0-5 volt spec for serial communications.....Rick B.