Pixl.js + Arduino shields

[gfwilliams]

Posted at 2018-05-23 by @gfwilliams

Hi! I'm adding some documentation and examples for adding Arduino shields to Pixl.js: http://www.espruino.com/Pixl.js#arduino

So far we have:

• motor driver
• Ethernet + SD card
• WiFi
• GSM
• Seeed Grove

Is there anything specific that you'd like adding? I'm thinking mainly cheap, common shields that might work well on a Puck.js.

[espruino-discuss]

Posted at 2018-05-23 by @yerpj

The Mikroe ecosystem is evolving fast, with huge amount of plug-in boards (named Click. Currently, more than 450 Click boards so far).
https://www.mikroe.com/click

It would be very nice to get support of this Click-to-Arduino shield :-)
https://www.mikroe.com/arduino-uno-click-shield

[gfwilliams]

Posted at 2018-05-23 by @gfwilliams

Any ideas what the library would actually do? Realistically I'm not going to be able to add drivers for 450 different boards :)

[espruino-discuss]

Posted at 2018-05-23 by J{a}SON

this data logging shield would be very convenient: https://www.adafruit.com/product/1141

[espruino-discuss]

Posted at 2018-05-23 by J{a}SON

the two other categories i'd put high on my projects are shields for relays (to control high voltage) and audio/dac to add music to my projects.

[espruino-discuss]

Posted at 2018-05-23 by @yerpj

Any ideas what the library would actually do? Realistically I'm not going to be able to add drivers for 450 different boards :)

Why not? ;-)

I was only thinking about really small code examples for setting up the communication interfaces (UART, SPI or I2C) on the correct pins. Or even better, a kind of abstraction layer for modules compatible with the "mikroBUS" (spec here: https://download.mikroe.com/documents/standards/mikrobus/mikrobus-standard-specification-v200.pdf)
In page 6 is showed the pinout of the mikroBUS.
I could be very cool to be able to get access to this by calling some thing like

var mikroBUS= new mikroBUS();

digitalPulse(mikroBUS.RST, 1, 5);
mikroBUS.SPI.send("some data");
analogRead(mikroBUS.AN);
//and so on...

[espruino-discuss]

Posted at 2018-05-23 by asez73

Hi,
Could you consider adding Lora and Sigfox shields?
Albeit long range they are rather energy savvy.

[espruino-discuss]

Posted at 2018-06-19 by @gniezen

I would love to have a USB host shield supported. The official Arduino USB host shield uses the ICSP header, so that won't work, but the Sparkfun one looks like it might work?

I noticed there was an earlier attempt at making a shim for the Pico, but it hasn't seen any activity in over 2 years. Now that the Pixl.js supports Arduino shields (and there's a shield adapter shim for the Pico), the main work is in porting all the libraries over, right?

[gfwilliams]

Posted at 2018-06-19 by @gfwilliams

Yes, it sounds like the SparkFun one would work fine - as you say, it's just just software support!

I imagine it wouldn't be super painful to get something simple like a USB keyboard working though. What peripherals did you have in mind that you wanted to connect?

[espruino-discuss]

Posted at 2018-06-20 by @gniezen

I have a bunch of different diabetes devices, from blood glucose meters to insulin pumps, that I want to connect so I can display the data on the Pixl.js screen. I see there are libraries for the various USB chips in these devices (e.g. Prolific, FTDI etc.) that were written for that shield, so I'm looking at porting those drivers. I already have JS code to read and parse data from the devices, but not from raw USB.

Maybe the HID USB driver would be a good start, as some meters use that to send data, and it can be used for keyboards too ;)

[gfwilliams]

Posted at 2018-06-21 by @gfwilliams

Ahh - interesting. I guess HID and virtual COM port (Prolific, FTDI) wouldn't be too difficult once USB was working.

It's just all the initialisation code that's required - I wonder if there's a super simple bit of example code out there for using the MAX3421E that would be a bit easier to use as a base than that library?

[espruino-discuss]

Posted at 2019-06-04 by @gniezen

I managed to get the USB host shield working in July 2018 and then completely forgot about it for a year. Oops! I just did a write-up (with source code) on Hackster.io: https://www.hackster.io/gerrit-niezen/adding-usb-host-support-to-espruino-2c494d

[gfwilliams]

Posted at 2019-06-05 by @gfwilliams

This is great! Thanks! Would you be ok with me turning this into a module?

[espruino-discuss]

Posted at 2019-06-05 by @gniezen

That would be great, I published it under the MIT license for this purpose! Let me know if there's anything I can help with.

[AndySmee]

I want to connect the pixl.js to an XBee Pro long range board. This shield looks the right form factor but no idea whether it will drive a Zigbee radio module or how hard it would be to drive from pixl

E.g. https://ebay.us/m/Ru38OT or https://ebay.us/m/AqxgVK

[gfwilliams]

I'd have thought it would be ok - as far as I know the XBee modules are ~3.3v and use UART to communicate, so would be a good fit for Pixl.js/other Espruino boards.

The only gotcha is whether the Arduino board you're using has level converters which attempt to boost the UART from 3.3v to 5v, in which case you'd need to find a way to disable those (it might just be that switch?). But that might be ok as I think a lot of newer Arduino boards are 3.3v as well.

The red board does have a 3x2 set of pins (ICSP?) in the middle which Pixl.js doesn't have (they're usually used for SPI but are available on the normal Arduino header too), so from that point of view the blue one might be better.

[AndySmee]

That's good... I had already taken a punt on the blue one, at £2.50! And a USB carrier to setup the XBee on a PC first

[AndySmee]

Looks a perfect fit. I presume I can't route the pixl's USB through to the XBee as even Arduino users have to remove their processor to avoid the USB being connected to both?

[gfwilliams]

You mean USB power? Or USB data?

On the Pixl there isn't USB data, but you could loop bluetooth data through to the XBee.

For example once you have set up Serial1 to connect to the XBee, you can have the following code:

E.setConsole(null, {force:1});
Bluetooth.on("data", d=>Serial1.write(d));
Serial1.on("data", d=>Bluetooth.write(d));

However by doing this, you have to move the console/REPL off Bluetooth which means you can't then program the Pixl until you reboot it without your code running (or maybe have some code that calls Bluetooth.setConsole() when a button is pressed)