Good bye and thanks for the fish

erco

Senior Member
Just for fun with the talk of oscilloscopes in the air I thought I'd see how well an AXE133Y 16x2 OLED board worked as an oscilloscope. It's not brilliant as it only has a resolution of 7 steps vertical and 80 horizontal with gaps but, with wire on C.0 and held to pick-up mains hum, it seems to capture 5.5 cycles of mains which gives a refresh rate of around 110 ms.

This code runs only on the AXE133Y OLED board; an LCD doesn't have the graphics mode the OLED does. It's thrown together and not optimised at all. I'll see how fast I can make an optimised version work later.
This sounds awesome, Hippy! Do you have any pics or video? That project deserves its own thread.

This $16 kit also has its place: http://www.ebay.com/itm/DIY-Digital-Oscilloscope-Kit-Electronic-Learning-Kit-DSO138-2-4inch-1Msps-HPj-/111953382352
 

stan74

Senior Member
If ever there was a reason for getting an OLED, I think I've found mine...
OK. I can't resist saying hippys code is what I tried sort of but using 8 lines and dividing y/8 to get byte positions then the bit from 128 adc samples in a buffer. The x axis is just 0 to 127. OK for dots but joined dots not. OK you could do a square wave with more code but not sine wave. Dots is cool 1st time you see it. Makes you want to try more ideas. Get a i2c one,only 2 wires and easy to get working with the picaxe init and control examples. Lots of fun for 3 quid.
 

techElder

Well-known member
:D :D :D

You,Tex and other ex colonies posts don't get deleted if they're off topic. Ironic it's uk users that ruffle feathers.
Let's leave it and get on with life.
So, Stan, you're still mad because of something that happened a couple of hundred years ago? :D
 

stan74

Senior Member
These lcds have hard ware scoll,just a few control codes so a scope could be just read adc/4 and a pixel position on the left column and scroll. The screen wraps around but the new sample would erase that. I got the same display as this on 28x2. It's 128 samples 1st,stored in 2 arrays,I erase the 1st pixel from the 1st array then replot it from the 2nd array 128 times,then swap the 1st array with the 2nd array and finally fill the 2nd array with new samples and loop. That way it's visually smoother. You don't notice 1 pixel changing. You could just plot the data then clear the screen and loop but it wouldn't look the same. https://youtu.be/-UVhBatrJH8
 

stan74

Senior Member
Nice finding there erco! Last time I checked on that KIT you had to solder it your self and having quite a few SMD components was a no-go option for me.
On the same link http://www.ebay.com/itm/Assembled-DSO138-2-4-TFT-Digital-Oscilloscope-Kits-DIY-Parts-1Msps-Probe/162200576235?_trksid=p2047675.c100623.m-1&_trkparms=aid=222007&algo=SIC.MBE&ao=2&asc=42816&meid=8c462a19ab434bb18aefb7937b05ff62&pid=100623&rk=2&rkt=6&mehot=ag&sd=111953382352
"Welded" $19. Look on youtube for ones that didn't work. Get a 2nd hand real scope for $50. I borrowed 1 of these. Hmmmm? https://www.amazon.com/SainSmart-Version-Portable-Handheld-Oscilloscope/dp/B00SXVUETU?tag=top505-20
 

mikeyBoo

Senior Member
hi stan87,
If you don't mind taking a lil' advice from a "colonial", here's what you may want to use if you need extreme speed (high-end robots, etc.). This allows using a Linux processor with 2ea. 200MHz real-time slaves (+ Arduino & Picaxe slaves if you desire). (e.g. stuff like toggling a bit @ 5nS rate)
(video tutorials) PRU-ICSS Resources http://beagleboard.org/pru
Also, if you want AI, look at TclTk, it's the only language that I'm aware of that can re-write it's code based on eval(ing) it's environment. The same app can run on Linux, Unix, & Windows (even the graphics).
Note: In spite of being a colonial, I believe I have royal blood (my mom always said I was a royal pain in the a..). Anyhow (all seriousness aside) have a fun day!
 

stan74

Senior Member
Seems there's lot's of programming going on in Australia. I remember Melbourne House/Beam Software in the 80s and a search for pic-basic-Australia is interesting. A lot of my father's family emigrated there in the 60's.
I can't get on with Linux mikeyBoo. I got as far as gpio on rpi and gave up. It seems like ms dos prompt. Freebasic has been ported to rpi and is more familiar. Linux IS rocket science.
 

SteveDee

Senior Member
...Linux IS rocket science.
You should try wiringPi + Gambas. Although Gambas is primarily GUI (like VB) you can still write non-gui Basic with it, and you get the benefit of a great IDE with debug features.

Linux != (rocket science)
 

stan74

Senior Member
Thanks SteveDee. I used pigpio and freebasic but for say a robot, picaxe was faster making one and easier to interface to stuff than rpi...unless you're familiar with linux and want to make it all complicated. Python on rpi is slow for gpio. Try just test pin on/off frequency on a 1.2 meg clock. KHz.
 
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