Asked — Edited
Resolved Resolved by DJ Sures!

Blockly Code In Mobile Interface Not Working On Stable ARC Version 4_9_2020

DJ, I can see the new ARC will be awesome!  But, the transition is a little painful.  In my Marks R2D2 project, it appears that the code I had written in Blockly on the mobile interface is no longer there.  For instance, a simple command to play a sound via a pushbutton on the mobile interface was written in Blockly as a play sound statement with a file name.

In the new ARC environment, the Blockly code is gone and its appears as an XML file statement.  When I tried to copy that statement over.... I get this pasted into this window... which kind of makes sense.  However, none of my code for the button logic works in the mobile app or in the mobile app preview screen in ARC.

1-|-Soundboard v4-|-Very Excited R2D2.mp3-|-1

Also,  i had a follow wall code segment in Blockly that now appears as a single line of xml - and its broken too.

Any idea how I can get this working again short of redoing my work?  It seems the sensors I have on the robot are working and the controls for the head and wheels.  So, its appears its all around the Blockly logic being busted.


Related Hardware EZ-B v4


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#1   — Edited

Unfortunately, it's probably not supported in mobile. Check the interface builder examples for mobile support of ARC controls. There’s a lot less features than the previous mobile app. The mobile app is mostly for supporting legacy ezrobots only. There’s no plan for future development of the free mobile app due to limited development resources. With the low cost of embedded computing solutions, it makes sense for Synthiam to focus efforts on making ARC better for autonomous robotics. Rather than splitting time for remote control of robots via an app

The suggestion is to put an embedded pc in your robot and use the web server for a custom ui to control ALL features of ARC - rather than partial features of what the mobile did.:) Then you can have a real robot doing awesome stuff rather than simple remote control of a mobile app.


JD, I was able to go back and put simple play sound items back in.  But, sensor readings I had displaying before don’t seem to work.

I understand where you are going. I like the Mobile app for the ease of teaching kids to code with basic stuff like movement, sounds, should maintain what you started from mobile app for the youngsters.

I am excited about python and java being added.  This will really be great.  I’ll review the documentation.


What sensors? If you have an example app that isn’t working I can take a look at it for ya. See if it’s supported or not


DJ, see the program "Marks R2D2 ARC Rework" on the Synthiam App store.   The three Ultra Sonic sensors don't show up in the app and the code that I had written to navigate using those sensors no longer works.   There was also a speed slider for general speed of the robot - it no longer shows up in the app either.

Thanks for your help.

#5   — Edited

Wait - before i dismiss functionality that has changed. What's the original project?  Before ARC


This is the project before ARC.....

Marks R2D2 PreARC


Did you look at the one i attached in the last message?


Yes. I tried that one.   It seems the sensor value overlays for the CPU temp, battery voltage, and the three ultrasonic sensors don't work in mobile - but show up in ARC when running on the PC.   Lets say I wanted to change to an onboard computer. It would have to be pretty small to fit in the R2D2.    I  have a RPI 4 w/2GB.  Can I interface with the onboard EZ-B via wifi or would I have to go to the board and solder a connection between the two?

#10   — Edited

Hi mstephens_42,  Fully functional  computers that run Windows 10 can now be real small and very powerful. One that DJ talks about and uses is the Up Board. It's the size of a credit card and comes with different options of memory and storage. The price range looks to be from 100 to 160 USD. DJ says the cheapest will hold Win 10 and ARC just fine. Anything more you need to get one with more storage. It also has 4x port USB2.0 on connectors, 2x port USB2.0 + 1x UART on header, 1x USB 3.0 OTG, 1x Gbit Ethernet (full speed), 1x DSI/eDP port, 1x Camera (MIPI-CSI), 1x HMDI, RTC. and a 40 pin GP Bus.

I'll let others help with how to interface with your RPI.

Here's a datasheet and the Up Board link:


Also, Maybe you would be interested in thei video:


David’s correct. I spoke about embedded computers in robots a number of years ago. But the technology was too slow and costly and large at the time. I predicted it would happen - just didn’t know when. The thing about the mobile app is it’s a dual development effort for us. We considered charging for the mobile app - but that still doesn’t cover nearly the amount of effort gone into it.

so the agreement with ezrobot was to provide three basic functionality of the app for their robots. And let power users embrace latte panda or intel up-board. I personally really dig the intel up board. The lowest cost option with 2gb ram and 16 ssd works great but it only has enough space for ARC and nothing else. I’ll do a live hack of setting it up if you guys want?

that being said, I did discover a bug in the mobile app with getting the temp and voltage as you brought to light. That means the update this week will include that fix. So, if that’s all you need then the mobile app will work.

but if you’re expecting to continue making your robot more awesome by using all of the real cool new controls being released weekly, you’d need ARC


One last unanswered part of the question - I have a EZB-V4 board in R2D2.  Can I interface with the onboard EZ-B via wifi from an installed small computer or EZB-V4  board and solder a connection between the two?  I am not sure If for now I want to buy another small computer. But, I will look at the RPI 4 2/2GB.


Thanks DJ, I'd love to see a Live Hack on the Up Board and how to control it from outside the robot.


Watched the UP board video, very impressive for $99.00 , I also would like to see you Live hack DJ  :-)

I am happy he tried Debian Linux in his example,



Both android and iOS apps were submitted today with a fix for the trackbar - it'll also fix your getping(). Expect a few days before they're available to your mobile device.


DJ, You are the most customer focused developer in the World!  You never cease to amaze me.  Your like everyone’s favorite Genius and our good friend at the same time.



Awe thanks man - that means a lot!


DJ my R2D2 Mobile app is back up and running! Thanks so much for fixing the slider and ultrasonic sensor functions in the mobile ARC.

I’m a Happy Camper!