Hello,

Any plan for a RS485 block ?

To anyone having issues with 40MHz oscillations, make sure to check your probe capacitance when you're checking things on your scope. The TXB0104 level shifter really struggles with capacitive loads ~70pF which is typical for a 1X probe. Try with a 10X probe and see if you're still getting oscillations.

Wish I'd realised this soooo much earlier... >:(

Does UART1 communication works now if power source is attached to this block too?

Will this power a Venus GPS (GPS-11058) if also connected to a battery block? Or is the power only in?

I bought one of these about a week ago since it was in stock and the Base block was not. Since it does not have an OTG connection, I spent a little time searching for a way to both update the Edison Yocto version and load Arduino sketches over wifi.

I have compiled a few of the things I learned here as a bit of a one stop shop for using the UART block and wifi to fully exercise the Edison. I apologize if this is all obvious to a lot of you, but hopefully some will find it helpful. This is all on OSX, and will work for Linux but probably not Windows.

To work with the Edison you really need to first update the Yocto distribution that ships with the device. It has a few issues such as the 5 second timeout bug that make it difficult to work with. There are also a few of the commands you will want to use that are not supported in the shipping version. But first, it's necessary to get the wifi working.

Run the Edison setup program.

configure_edison --setup

You will need to get the wifi working and set up a root password in order to use ssh over wifi. I was able to use the above setup procedure to get the Edison connected to my wifi, but there is a lot of info on the Intel Edison forum on different ways to approach this.

Once you're on wifi, there are a couple of ways to update Yocto over wifi. The way Intel recommends seems pretty safe, but it's a little unclear of it is supported with the "as shipped" version of Yocto. The method I used is here - see wbp's post #19 towards the bottom of the page. I was able to make it work, but be aware that doing this incorrectly can brick your Edison.

Once Yocto is updated you can actually use the Edison. I initially followed the SparkFun tutorial for programming with Eclipse and had good results. However, the Arduino interface was the one I really wanted to get working. This required a little work to get away from the OTG port and onto wifi. Here are the steps I used (Again, I'm using OSX).

First download the Arduino software for Edison and your development platform. Ignore the fact that the Arduino/Intel site directs you to Galileo software - this is what you need for the Edison too.

Start up the Arduino package for Edison and open preferences. Under preferences, you'll find an option check box that says "Show verbose output during upload" that you will want to enable. Close preferences and compile and run an example sketch (blink will do). The sketch should fail uploading since you don't have a USB cable connected to the OTG port. Look in the message window along the bottom of the Arduino development environment and scroll up until you find the line containing clupload_osx.sh (for Mac - look for clupload_linux.sh for linux and clupload_win.sh for windows). Note the file path. You will need to modify this file in order to automatically upload to the Edison over wifi.

Make a backup copy of the clupload_osx.sh file (cp clupload_osx.sh clupload_osx.sh.original - or something). Use a programming editor or whatever method you are comfortable with to make a file containing:

#!/bin/sh

set -e

HOST=192.168.0.70 # CHANGE THIS TO YOUR DEVICE'S IP

SKETCH=/sketch/sketch.elf

OLD_SKETCH=${SKETCH}.old

ssh root@$HOST "mv -f $SKETCH $OLD_SKETCH"

scp $2 root@$HOST:$SKETCH

#Give the host time to stop the process and wait for download

sleep 1

ssh root@$HOST "chmod 755 /sketch/sketch.elf"

ssh root@$HOST "systemctl restart clloader"

echo "Success"

exit 0

This is a shell script I modified from Labby's site. You can use his or mine - I modified his for a couple of reasons I list below.

I can't remember if the /sketch directory originally contained a sketch.elf file or not. Verify if the file is there with ls /sketch

If /sketch/sketch.elf does not exist, the script above will fail. An easy way around this is to create a dummy file as a placeholder for the script (assuming /sketch/sketch.elf does not exist and the script fails). To create the dummy file:

cp /dev/tty /sketch/sketch.elf

<hit return>

<hit control c to exit and save>

ls /sketch (to verify the file was created in the correct place)

It is convenient (if not necessary) to set up a passwordless login for ssh to make all of this work correctly. Labby also gives a good description on how to do this for Linux and it works the same for OSX. I don't speak Windows enough to know what is required there, but I found a few search results that seem to show how to do it.

If you have modified the clupload_osx.sh file in the original path discovered through the Arduino Programing environment, and your passwordless ssh is correctly set up, you should be able to compile and download a program to the Eddison wirelessly (quit and restart the Arduino software after modifying the clupload_osx.sh file).

You can verify the Arduino software is uploading correctly by monitoring the Edison console and looking into the /sketch directory on the Edison. If you have successfully uploaded a new sketch you can see the timestamp on the /sketch/sketch.elf file (on the Edison) reflect the current date. Compare it to the date obtained by running date on the Edison.

A potential hitch here... The Edison Yocto /root partition will probably be at nearly 100% capacity ( verify by running df on the Edison console if you wish). This causes the Arduino software (and our new script) all kinds of issues since the Edison will report that it is out of space about every other compile.

One way around this is to repartition the Edison to get more room on /root. Probably the best long term solution (but I haven't done so yet...). Another way is to move the sketches to the home directory and place a symbolic link named /sketch/sketch.elf in the original location. This location is where the Arduino emulation for the Edison expects the sketch.elf to be located, and it is fairly simple to fake it out and get ourselves some available disk space.

To do this, I created a sketch directory off of /home/root. On the Edison:

mkdir /home/root/sketch

Then (because of what the shell script expects), I copied /sketch/sketch.elf to /home/root/sketch/sketch.elf

cp /sketch/sketch.elf /home/root/sketch/sketch.elf

and removed the sketch files from /sketch

rm /sketch/sketch.elf

rm /sketch/sketch.elf.old

(the second file may not exist, but it won't hurt to enter the command...). Next, I created a symbolic link to the /home/root/sketch/sketch file like this:

ln -s /home/root/sketch/sketch.elf /sketch/sketch.elf

Which should show up as a symbolic link (ls -al /sketch).

Finally, if you have done this you need to change the clupload_osx.sh file line:

SKETCH=/sketch/sketch.elf

to:

SKETCH=/home/root/sketch/sketch.elf

which should make the Arduino software update the files in the /home/root/sketch directory and leave the symbolic link /sketch/sketch.elf alone.

Hope this helps. Apologies in advance to those who find all of this obvious! Please correct any mistakes in the above as you discover them. Thanks

I can confirm that the block can properly power a stack but the UART does not work as explained in the review (high frequency oscillations messes up the signal). Has there been any update on this?

The TXB0104 used for level shifting will oscillate at ~40MHz when connected to longer wire (1m cable of FTDI converter is enough). Placing series resistors before cable seems to solve this (I used ~2k2 for TXO and 220R for RXI, 3.3V FTDI cable then works).

I bought 3 of these a while ago and have not been able to use any of them. The console just shows a bunch of garbage. I'm pretty sure I'm doing everything correctly. Is this a known issue? Is there a workaround? I really need to use these.

Does this breakout UART_1 also? Can it be used to hook up a serial device like xbee? if not, which block can do that cheaply? Thanks

This block would make a lot more sense if it included a 5.5 mm barrel socket for power from a 5v brick; even better a provision to alternatively add a LiIon for power with charging from either the USB or the 5.5 mm socket. Maybe that would be escalating the scope too much.