Hi all,
Have been playing around with my OmegaBot some more, and I've noticed that if I don't have the LiPo battery completely charged, the Omega turns off (stops responding, LED goes out) the instant I use one of the PWM outputs.
How can this be? I'm using an external 6V power supply (4 AA batteries) on the PWM Expansion barrel jack, and this supply is supposed to be isolated from the Omega's 5V supply (info)
Any suggestions appreciated
Yes, those work perfectly and are used to determine the device is there.
But there is no way to read the actual range data without a lot of i2c back-and-forth with their custom protocol.
There are python libraries to handle this, but none of them work on the Omega (yet)
Hi all,
I recently picked up a VL53L0X "Time of Flight Range Sensor" (Adafruit, datasheets) to use with my OmegaBot and other projects, ideally with Python.
It was only $15, but I was still dismayed to learn that, while it uses i2c, the registers aren't public and they have a proprietary protocol to talk to it. It does work though, it shows up in i2cdetect. There are precompiled libraries for Raspberry Pi etc, which obviously won't work on the Omega as-is. (I did try, there's a couple in the openwrt Python package library but they just crash on install)
So I'm wondering what the shortest path would be to get this running? There's a few readily available C libraries that would have to be re-compiled as a python module, but I have no idea how difficult that is for the Omega.
Adafruit library: https://github.com/adafruit/Adafruit_VL53L0X
Pimoroni python library: https://github.com/pimoroni/VL53L0X-python
Python library for Raspberry Pi: https://github.com/johnbryanmoore/VL53L0X_rasp_python
etc, etc.
Any advice?
@György-Farkas In series, using single-use for now since that's what I have on hand. But rechargeables would probably work.
The battery holder is just one of these, though it came with the R/C car and the cover is a slightly different shape.
Thanks for the detailed explanation!
Though it makes me wonder why GPIO11 is on the breakout header at all. It doesn't seem usable by end users.
A couple of years ago I posted my first version of an Omega2-Powered Robot which was a lot of fun and well received.
However, it had a few issues:
So I've made a new one, using the same basic architecture (Omega2, PWM Expansion, python) with a few improvements:
Here it is!
It works really well! Not visible are the 4x AA batteries in the base to power the motor.
The code and datasheets are up on GitHub if anyone's interested: https://github.com/LeifBloomquist/OmegaBot/
I'm also working on a way to control it with the LEAP Motion (hand gestures), will post a video once that's working.
Dug a bit deeper and it seems GPIO11 is reserved for the reset button, etc. It's just not shown on the dock pinouts, it appears to be free i.e.
Reference:
https://docs.onion.io/omega2-docs/using-gpios.html#pins-at-boot
http://onioniot.github.io/wiki/Documentation/Hardware/Omega-Hardware.html
So I think I'll be OK using a different GPIO, but would be nice to understand what's going on here a little more and have that shown in the dock pinouts.
Hi all,
I'm trying to use the PWM Expansion module along with a GPIO (11) as an output. Though as soon as I set the output mode on the GPIO, all the I2C devices vanish, disabling the PWM Expansion module.
Nothing is connected, just the Omega2 on a Power Dock with the PWM Expansion on top. I even have a rubber spacer in between the two to avoid any shorts. I've used the PWM Expansion on its own in past projects, has worked fine.
On bootup, everything looks fine:
root@Omega-10D9:~# i2cdetect -y 0
0 1 2 3 4 5 6 7 8 9 a b c d e f
00: -- -- -- -- -- -- -- -- -- -- -- -- --
10: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
20: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
30: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
40: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
50: -- -- -- -- -- -- -- -- -- -- 5a -- -- -- -- --
60: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
70: 70 -- -- -- -- -- -- --
Great! 5A is the PWM Expansion (not sure what 70 is). But then I run this little python script:
import onionGpio
gpio11 = onionGpio.OnionGpio(11)
gpio11.setOutputDirection(0)
And wham, no more I2C devices:
root@Omega-10D9:~# i2cdetect -y 0
0 1 2 3 4 5 6 7 8 9 a b c d e f
00: -- -- -- -- -- -- -- -- -- -- -- -- --
10: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
20: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
30: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
40: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
50: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
60: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
70: -- -- -- -- -- -- -- --
Any suggestions? I specifically chose GPIO11 because it's not associated with any other function.
Thanks!
I'd love to be able to get a couple of pre-made, populated PCBs for this. Looks great.
That might not even be the best way to go about it - I hacked around a bit until I got something that worked. Pointed inittab to that script file.
More details and discussion in this thread: https://community.onion.io/topic/2239/commodore-64-supercharged-by-omega2-pictures
I've made a little board that does exactly that! They key is the MAX3232 RS232 level shifter.
https://community.onion.io/topic/2291/custom-omega2-db25-rs232-dongle-pictures
@leo-moura No, this post is that tutorial 
There's really not too much to it. I posted the Fritzing board design files though, enjoy:
https://github.com/LeifBloomquist/ProjectOmega/tree/master/Hardware/OmegaDB25
Also try rebooting your router - it's the common element. I had an issue similar issue with a couple of my Omegas, and it turned out to be the router all along.
At the Vintage Computer Festival Midwest last weekend, I also got to test it on a serial terminal printer, which worked great!
I had this same problem with two of my new Omega 2+s last week. After lots of searching around and digging into config files...I tried power-cycling my router and then they both worked. Might be worth ruling that out first.
I also got it working on a Tandy m100, at a blazing 300 baud!
As a followup to my Commodore 64 Omega2 Interface, I've designed a small and simple custom board that allows the Omega to be connected to any "retro" computer that has a DB25 RS232 port.
As you can see, it works beautifully on a WYSE terminal in VT100 mode!
The hardest part was waiting 6 weeks for the super-rare 2mm headers to arrive from China 
Thanks, that does the trick.
No documentation that I know of,
How do you not have documentation for the code that ships on your own product? That fascinates/baffles me.
found the -c option by running ash --help
Fair enough, but the output is pretty cryptic:
root:~#ash --help
BusyBox v1.26.2 () multi-call binary.
Usage: ash [-/+OPTIONS] [-/+o OPT]... [-c 'SCRIPT' [ARG0 [ARGS]] / FILE [ARGS]]
Unix shell interpreter
I don't see how you can glean much from that.
Figured out a good solution after a bit of digging. Shell script:
#!/bin/ash
stty -F /dev/ttyS1 2400
while :
do
echo "" >/dev/ttyS1
echo "Onion Omega 2+ on Commodore 64!" >/dev/ttyS1
ash -l </dev/ttyS1 >/dev/ttyS1 2>&1
done
Right now I'm launching it manually, but could do it from inittab or some other approach at startup.
Still two outstanding questions:
I've done something similar with a Raspberry Pi, but I much prefer the Omega2's form factor, looks like it would fit tidily in a retro cartridge case, for example.
Some minor issues though:
There isn't quite enough oomph from the C64's User Port to power the Omega2 directly (through a voltage converter) - max at 5V is officially 100 mA but it can usually be pushed safely to 200 mA with a good power supply though. Still not enough for the O2+ unfortunately.
It's a little awkward to get a login prompt over ttyS1 as well as at 2400 baud, as per this post. A login prompt isn't strictly necessary, you could have a python script running for example to handle whatever, but a real prompt is pretty cool.