Digital Pot setup

[CDRIVE]

In 1979 my group at Digital Equipment Corporation got one of the first VAX-11 780s. It only cost about $1M and had an entire 1Mbyte of that new-fangled semiconductor memory! I worked on the COBOL compiler.

Bob

Bob, you and my wife have something in common. She was a senior programmer analyst in a Assembler and Pascal but most of her career was spent programming in COBOL. Mainframes still use it. The so called "Glass Ceiling" is a bunch of BS!! The girl retired making >86K!

Chris

 

[CDRIVE]

Justin, your circuit will look like this. Start programming!

Chris

 

[JPU]

Start programming!

Chris

Chris, I hope that is a joke! Start programming? That's like saying to someone who has never seen a car and has just seen one go past, "ok, here is yours, off you go", or telling someone "yes sir, this helicopter is capable of loop the loop, have a go!"

Start programming? The first thought that came into my mind was "program what?" and then "what with?" and then "what do I actually program into it?"

Please, please after all the posturing over who has got the biggest chip!, please don`t leave me like this!

I have had a look and is this a good start, shall I order it? http://www.picaxe.com/Hardware/Starter-Packs/PICAXE-Development-Starter-Pack/

Thanks

Justin

 

[BobK]

Justin, your circuit will look like this. Start programming!

Chris

Your design is way too compilicated. I can eliminate 2 of the 7 parts. The pullups are not needed as their are internal pullups you can enable

Justin,

The first step would be to get the PICAXE development system, which I believe is free. Perhaps CDRIVE could tell you how and point you to some tutorials to get you started.

Bob

 

[JPU]

Justin,

The first step would be to get the PICAXE development system, which I believe is free. Perhaps CDRIVE could tell you how and point you to some tutorials to get you started.

Bob

Hi Bob,

Did you take a look at the link I supplied to a PICAXE board. I'm not sure which development system I need and the system I linked to, I believe is capable of programming all the current chips from PICAXE.

Is it what I need?

Justin

 

[CDRIVE]

Your design is way too compilicated. I can eliminate 2 of the 7 parts. The pullups are not needed as their are internal pullups you can enable


Bob

I'm going to have to consult with the new manual for *M2 parts before I agree. The *M parts did not permit this and had no internal pullups or pulldowns. The manual for the M parts specifies pulldown resistors for all inputs and switching them Hi. Though I used reverse logic (as in my schematic) with pullups many times. Did you read that in the M2 parts manual?

Chris

 

[CDRIVE]

I have had a look and is this a good start, shall I order it? http://www.picaxe.com/Hardware/Starter-Packs/PICAXE-Development-Starter-Pack/

Thanks


Justin

That's waaaay more than you need to get started but since I'm an old guy that still loves toys...Soo yes, get it, cause it's compatible with most of their chips. Now that's a 'Development' board, not what you'd use for your finished projects. Your project board won't be much larger than the 08M2 chip.

I have to go back up there and see exactly what you should download and the project board most suitable for your project.. I have to do this myself because I have the older M version compiler and pdf manuals.

Chris

 

[timothy48342]

Hey, fist I love this thread. I have learned a lot about development option from you guys discussing the ways to do this.

I want to point out that the link justin posted to The Starter Pack comes with the 18M2 instead of the 08M2. (And justin, if you scroll that page down, you'll see "Related Products" and the first one has 8 pins and that's the 08M2 that Chris used in his schematic and it's about a pound fifty as opposed to fifty pounds for the Starter Pack.)

I am wondering two things. (Maybe justin is wondering, too)

1) If you wanted to pass on the development board... ("Starter Pack") ... How would you upload your final code into the chip? Do you need to buy a programmer? Do you need to build a programmer? (or uploader... or downloader... I don't know.)

2) BobK mentioned, "to get the PICAXE development system" which might be free. What is that? Is that software? If so is it downloadable? (extrapolating...) If someone didn't even buy anything yet, could they download the software that simulates the PICs and compiles code all for free?? (And what is the download link?)

-tim

 

[JPU]

I have to go back up there and see exactly what you should download and the project board most suitable for your project.. I have to do this myself because I have the older M version compiler and pdf manuals.

Chris

Hi Chris


Great, I will order it, I love my toys too, its nothing to do woth age.

I will wait until you have a look and come back to me with what else I need to order from PICAXE so that I can get my project build under way.

If you get a chance soon, it would be great as I could order the parts before I leave for work in the morning and with luck get them before the weekend so I can play with it over the weekend.

Thanks

Justin

 

[JPU]

I am wondering two things. (Maybe justin is wondering, too)

1) If you wanted to pass on the development board... ("Starter Pack") ... How would you upload your final code into the chip? Do you need to buy a programmer? Do you need to build a programmer? (or uploader... or downloader... I don't know.)

2) BobK mentioned, "to get the PICAXE development system" which might be free. What is that? Is that software? If so is it downloadable? (extrapolating...) If someone didn't even buy anything yet, could they download the software that simulates the PICs and compiles code all for free?? (And what is the download link?)

-tim

Tim, I was just about to type exactly that!

Great minds!

Justin

 

[CDRIVE]

Justin, if you're running Windows then download this package.

http://www.picaxe.com/Software/PICAXE/PICAXE-Programming-Editor

The pdf manuals should be included in the distribution setup .exe.

Chris

 

[JPU]

Chris

OK, done,,I have got some reading to do!!

Ill order the program board I mentioned in the morning and hopefully you can let me know exactly which project board I will need.

Your help is appreciated..

Justin

 

[CDRIVE]

Tim, I was just about to type exactly that!

Great minds!

Justin

All Picaxe software is free except for PicaxeVSM. This is because it doesn't belong to Picaxe. PicaxeVSM is a Spice program copy written by ISIS / Proteus. It is not needed to program a Picaxe chip or write your programs either.

Most PC's today don't have RS232 (Serial Port) interface to the outside world. Picaxe sells the AX27 USB/Serial cable to download your program into the chip. It comes with a disk that will install the drivers for it and assign a virtual serial port on your machine. When you plug it in it will re-register itself and show up in the Device Manager under Serial Ports. At the Picaxe end of the cable the interface circuit to the chip is trivial and described in the pdf manuals. That development board that you mentioned has everything you need and then some. The download interface circuitry is included on that board and the AX27 plugs directly into the board and routs the program to the Serial In pin on the chip.

That said don't order anything until we've compiled all that needs to be shipped. You only want to do this once.

Chris

EDIT: The AX27 is an incorrect part number. The Picaxe server is down right now, so I can't get in to give you the correct number now. I'll post it when it's back up.

EDIT Edit: It's an AXE027

 

[gorgon]

At last a schematic of the logic solution. You need a +5V regulated supply for this. With a light sprinkle of decoupling capacitors, like 100nF. The 68k resistor may need adjustment to get the frequency you want. It's depending on the hysteresis in the hc132.

TOK

 

[CDRIVE]

At last a schematic of the logic solution. You need a +5V regulated supply for this. With a light sprinkle of decoupling capacitors, like 100nF. The 68k resistor may need adjustment to get the frequency you want. It's depending on the hysteresis in the hc132.

TOK

gorgon, If I ever saw an exemplary example of the superiority of uC's over digital logic/analog blocks, this is it. It's a stellar and laborious effort though! I don't have that much energy!

 

[CDRIVE]

Justin, The AX27 USB/Serial cable is an incorrect part number. The Picaxe server is down right now, so I can't get in to give you the correct number now. I'll post it when it's back up.

Chris

Edit: It's an AXE027

 

[CDRIVE]

This starter pack includes the USB/Serial cable (AXE027) and driver software.

http://www.picaxe.com/Hardware/Starter-Packs/PICAXE-Development-Starter-Pack/

Buy a few 08M2 Chips. They're cheap!

http://www.techsupplies.co.uk/epage...h=/Shops/Store.TechSupplies/Products/AXE007M2

Buy one of these. It's a small project board that you can build your finished circuit on.

http://www.picaxe.com/Hardware/Project-Boards/PICAXE-08-Proto-Board/

It includes the programing jack and components. If you test your programmed 08M2 on the larger development board you can omit installing the programming jack and associated components on this little board.

They sell miscellaneous components. So, if you need anything else look through their pages.
I do believe that's about it.

Chris

 

[CDRIVE]

Justin, does the manufacturer of the motor controller spec the input impedance / Resistance of the 0-5V speed control input? This figure is rather important for the DAC output to work properly. If it's too low I'll have to add a buffer to the circuit.

 

[(*steve*)]

I've moved the PICaxe Vs PIC stuff to a new thread because it's cluttering this one a bit.

We should probably try to keep this one about the project and have our side-discussion elsewhere.

 

[JPU]

Justin, does the manufacturer of the motor controller spec the input impedance / Resistance of the 0-5V speed control input? This figure is rather important for the DAC output to work properly. If it's too low I'll have to add a buffer to the circuit.

Chris

I've had a quick look,,, this is what it says..

To control the speed of the motor with and external
DC voltage, INT/EXT SPD switch (SW1-POS1) must
beswtich to the ON position.
(0VDC (min) - 5 VDC (max)

If you need more info I`ve emailed them so awaiting a reply.

Justin