Arduino - pricey but good, Ti Launchpad $4 delivered - but not so easy to drive - not any more!

[golfnut]

I just ran some basic Arduino sketches on my Ti Launchpad with zero fuss - my chip was M430G2553 (with internal 16MHz clock)


If you want throw away price processing - Ti MSP430 range is hard to beat.

There is a clone of the Arduino Sketch compiler IDE called 'Energia' google for it on Github


One pain is that you need code composer Studio downloaded from Ti as it uses drivers etc from that. This download is an evening of your pc's life. (I had it in already from previous experiments using CCS)


I just put Dons VDI code into my Launchpad - I cant verify as no display Plus the A/D are 10bit in Launchpad so will need some tailoring - bit beyond me.




Launchpad is 1/5th the price of uno

S

[golfnut]

Basic vdi

Had chance to look at Ti Launchpad.

Got some basic phase angles from two A/D reads - result sent out to serial port.

This was two equal voltages in disc and geb inputs



second picture was in error - dont know how to erase it..

s

[dfbowers]

Had chance to look at Ti Launchpad.

Got some basic phase angles from two A/D reads - result sent out to serial port.

This was two equal voltages in disc and geb inputs

[ATTACH]22817[/ATTACH]

second picture was in error - dont know how to erase it..

s

That's encouraging, that you at least got it to run. Maybe you could just implement an LED bar graph with it? That would be easy and usable I would think..

I recently picked up an Arduino Micro for about $25.00... The same footprint as a stick of gum!! Now I can shrinkify!!
Also, I made a few improvements to the code I have been using. By playing with when the analog sensors are triggered and the number of samples taken more consistent readings can be realized, especially when the distance between the coil and targets vary widely:

[joop]

If you want to develop with Arduino cheaply then slap an ATmega328 on a breadboard and add a bootloader through a programmer using the ISP interface, for example with the USBtinyISP programmer. You only need a couple of components, see http://arduino.cc/en/Main/Standalone (plenty other examples on the internet). To upload the actual program from the arduino IDE, use a separate USB to serial interface, for example the USB-BUB. I have done it a couple of times, for 5 euro you have a working system.

[golfnut]

Cheers Don.

I was thinking along these lines last night for when to read, and how to use qualifying samples in a block average etc. Many ways to skin all of those cats!


Toying with 3rd CH measuring the Comp Threshold volts,


So,

While X AND Y are above Thresh
take readings ( each of which are checked for level) to a maximum of say 10 times.


So it only displays from a valid 'hit'. My starting point was going to be use the Copmparator output to (a bit like a button push) to start analog reads.

I find this stuff interesting but slow going.

You mentioned one time you were a 'C' grade for this type of stuff - I would kill for a 'C' grade at this stuff !!

Steve


http://uk.farnell.com/jsp/displayPro...roductlistings

2 processors with on board 16MHz ref, a Dev board, Spare headers, a watch xtal for RTC projects, USB lead.... For Less than a beer (in London anyway!)

[golfnut]

bootloader etc

Joop, sounds good, I like the 5Euros bit.


I have found the Launchpad using the MSP430G2553 reasonably easy - not absolute beginner stuff though.



I found the IAR systems IDE - unreliable for usb driver, so emulation/ debug/ Flash was erratic - I am on XP SP3.

The Ti Code Composer Studio is more usable if a bit cryptic in obvious things like Flashing your code in!

Ti have a GUI approach for making code called GRACE - but Ive found all of them a bit wanting TBH.


A clone if the Arduino IDE has been cleverly made called Energia, on Github. Lots of the ARDUINO example sketches can be cross platform ran onto Ti Launchpad - this is what my code ran on.

S

[joop]

For what you get, you can't beat Launchpad's price... It's a good platform if you want to get a feel for microprocessors.

[dfbowers]

If you want to develop with Arduino cheaply then slap an ATmega328 on a breadboard and add a bootloader through a programmer using the ISP interface, for example with the USBtinyISP programmer. You only need a couple of components, see http://arduino.cc/en/Main/Standalone (plenty other examples on the internet). To upload the actual program from the arduino IDE, use a separate USB to serial interface, for example the USB-BUB. I have done it a couple of times, for 5 euro you have a working system.

I have been thinking of that but I'm not quite that advanced yet. That may be the next logical step. Thanks for the link.. That looks great!

Don

[golfnut]

I had a small model servo in the scrap box - makes a quick VDI. Shown is 45deg.



S

[dfbowers]

That's pretty neat.. I have boxes full of servos as well. How did you write your code?

[golfnut]

I did it this way Don. There is an example sketch with srvo stuff in, I copied some of that and made it fit. There is a scaling function which maps a number range to a degrees on the servo range. In the worked example it had (0 - 1023 , 0 - 180) i.e. an 8 bit a/d read to 180 max sweep. I alttered it to my degrees result of 0-90, to a servo sweep of 0-90, so 1:1 scaling. I havent tested it much, only two equal A/D inputs for 45deg. If I get 2 pots, 6 wireses and some test assy time I can verify more..



S

[golfnut]

When to sample

I have been thinking of when to sample the A/Ds and I think its a really important thought. The sampling will affect the user sens markedly if done without care.

1) We should only A/D Sample the Rx CH's outputs when there should be Rx signal present. We know when that is - huge advantage.

(We could use the Disc Gating signal to fire conversion - similarly use the GEB Gating sig to fire conversion)

Ends up like lock-in type, gives a waveform ave rather than a random ave, (the signal and the noise are not randomly sampled) Benefit is we sample WHEN there is signal there, Signal goes up in relation to noise, Signal to noise improvement.

I know all of the grown ups know this already and Im fairly confident this approach is the case in commercial digitised kit.

S