Do I Need a PropPlug?
naf456
Posts: 3
Hey.
I'm new to micro controllers and circuitry in general, let alone the Parallax Propeller.
I was wondering if it was vital to buy a PropPlug? - or can I just use a USB interface and wire the pins directly to my PC?
The Prop plug has an IC built onto it - so I'm unsure whether the prop plug does some trickery with the Propeller.
I'm not new to programming however - have done pieces of IA-32 assembly before, and plan to bypass Spin and just program directly in assembly.
I am also unsure of the circuitry require to display video output on a screen- would I need a Digital to Analogue converter?
I plan on building a basic computer on a breadboard without AID of a development board.
I'm hoping to incorporate the famous SID audio Processor and create my own Commodore 64 Clone
Thanks.
Nathan.
I'm new to micro controllers and circuitry in general, let alone the Parallax Propeller.
I was wondering if it was vital to buy a PropPlug? - or can I just use a USB interface and wire the pins directly to my PC?
The Prop plug has an IC built onto it - so I'm unsure whether the prop plug does some trickery with the Propeller.
I'm not new to programming however - have done pieces of IA-32 assembly before, and plan to bypass Spin and just program directly in assembly.
I am also unsure of the circuitry require to display video output on a screen- would I need a Digital to Analogue converter?
I plan on building a basic computer on a breadboard without AID of a development board.
I'm hoping to incorporate the famous SID audio Processor and create my own Commodore 64 Clone
Thanks.
Nathan.
Comments
Page 5 of the Propeller's datasheet has a schematic for a two transistor serial port connection. If your "USB interface" is a USB to serial converter, it needs a DTR line as well as rx and tx lines to work the two transistor circuit.
There are several Propeller boards with a USB connection already on it. The QuickStart is one of these.
The video (NTSC) circuit is just a three resistor DAC.
No, definitely not. You will need a serial interface to program the Prop. This can come in several forms:
2. PropPlug, which interfaces the logic-level Prop pins to a USB port.
3. Boards which already have USB on them, such as the Propeller Demo Board, QuickStart, or Prop BOE.
4. Propeller products using RS232, which require an RS232 interface or an RS232-to-USB adapter.
-Phil
Propeller Platform USB is another way to go for more advanced stuff...
I'm such a fish out of water with this stuff it's unreal.
I guess I have work to do.
I haven't a clue between the difference of a serial and USB port - I know there is a difference, just don't know what it is yet.
So if I create a serial port, how do I connect it to my PC? via a serial to usb wire?
Actually How about I read the manual
Anyway, there are lots of USB to serial port adapters that plug into a USB port and provide the functional equivalent of the older serial port. Look at the various articles in the Wikipedia for details. Some Propeller boards provide the USB to serial interface and some, like the Protoboard, require you to provide one (like the PropPlug).
As for the serial part, well this is where it gets a bit complicated... If you don't have a serial port (or RS-232), you'll need to get one. It can be usually found on a PCI/PCI-E card, USB or ExpressCard. PCI/PCI-E and PCI-E based ExpressCard in general work better, but for Propeller programming, USB works without any problems too and may be considerably cheape. When you get the serial port, you'll most likely have a DE-9 (some call it DB-9) connector on it. For PCs, the pinout is standardized and each pin has its name. Just look on Google for `serial port pinout` and you'll get lots of images. Get a female DE-9 plug and solder wires to appropriate pins so that it correctly mates with the DE-9 connector of the serial port. Then connect the wires to the circuit in the manual and that's about it. Don't forget that you'll need a power source for the Propeller! The easiest way would be to get say a 5 V USB charger and use a 3.3 V regulator with it. Alternative would be to use a 9 V wall wart and a 5 V and 3,3 V regulators.
It's all very simple when you get used to it, but at first it may look a bit complicated. Just keep in mind that there are lots of friendly people here and if you're feeling uncertain about a step, do ask for clarification.
You have to add some Spin code to start any assembly program. I think about Spinless PASM only configuration, but it is not very easy. When Propeller boots, it starts with Spin interpreter.
Commodore clone.. It (and/or Atari clone) is my dream...
It seems to be possible with a Propeller, to do a C64 or Atari 8-bit clone
Your computer may not even have a serial port. A lot of new computers only have USB.
The PropPlug can really save you a lot of grief if you're just getting started in a setup that doesn't have it's own USB connection...
There's enough new stuff to learn without fighting with the connection to the PC.
I'll second the purchase of the Quickstart. Pick one up from here and you'll get an additional board with it.
Edit: SIDcog is an awesome nod to the Commodore 64. Take a look at FemtoBASIC as well. I arrived here a few years back when someone was working on a C64 emulator. It was never finished, but it was enough to get me hooked on the Prop.
OBC
No you don't need a prop plug but it probably is the easiest solution. I have an older PC with a real serial port. On my propeller boards I use a Max3232 chip and a D9 female socket and I do that because once the propeller is programmed I then get a free real serial port I can use to talk to all sorts of things.
But... modern PCs don't have serial ports any more. So you need a USB to serial adapter. And if you hop on ebay you will find these sometimes for $2 including shipping, whereas the propplug is $15 and then there is shipping as well.
However, there is a catch. Those USB serial cables don't work with the current propeller software. More specifically, they work with the old propeller software from about 4 years ago but not with the latest versions. I've never got an answer from Parallax about this one (I even started a thread about it once) and I am convinced there is just one line of code in the DTR reset timing pulse that needs changing, but the bottom line is that you can't use your $2 USB serial cable for programming. You *can* use it though for serial comms to the propeller once the propeller is programmed, and that includes even using the control pins.
One answer is to search for USB to serial cables that have the FT232 chipset. eg here is one on ebay http://www.ebay.com.au/itm/Black-FTDI-FT232-RS-232-RS232-Serial-USB-Adapter-Cable-w-Magnetic-Ring-/170833794906?pt=UK_Computing_Parallel_Serial_PS_2&hash=item27c67cd75a and you can find others, including little adapters that look like the propplug if you search for 'ft232 usb serial"
The catch there is that the cable above is $17 (including shipping).
So you don't save much on ebay compared with getting the cables from parallax. Perhaps it is a giant conspiracy? Or more likely, because most everyone is using the FT232 chipset, the bug that crept into the propeller software years ago took until recently to get picked up.
Another option is to get a FT232 chip but they only come in surface mount and are harder to solder.
If I was starting out I'd buy a propplug and then at the same time get some other parts like propeller chips and then save on the shipping.
You only need 3 resistors which build a 3bit DAC - see the Demoboard schematic. If you want to build it on a breadboard, and with your current knowledge, a PropPlug is by far the simplest solution.
Don't forget two 100nF bypass capacitors between 3.3V and ground on both sides of the DIP Propeller chip. These capacitors are not shown in the schematics with the PropPlug interface.
Andy
Or if you're like me and are always looking for excuses to breath fiberboard dust (and save money) you could buy some USB Propeller Protoboards and cut the USB section out to make a DIY Prop Plug. I added headers to the orignal USB Prop board and my DIY Prop Plugs work on both the modified boards and regular Propeller Protoboards
I do have two Prop Plugs but neither of them work anymore. I thought if I were going to continue to kill them as fast as I did, I'd need a cheaper source.
As others have said (including myself) it's hard to go wrong with a QuickStart board. Not only does it have a USB connection to let you program it right away, it's also powered by the USN cable.
Everybody shoud have one. I could not live without one.
Not just because some boards do not have usb - you can use the prop-plug to connect to different pins for debug output or to simulate and view serial comms between propeller and whatever you connect (GPS, second propeller, serial camera, etc.)
So a Prop-Plug is very versatile besides programming the propeller.
duanes solution is somehow brutal but I like it.
enjoy!
Mike
(1) Is it problem only with Propeller Tools? What with BST?
(2) If it is problem with DTR reset timing pulse, can it be corrected in hardware?
I need to check the latest version but I think BST was ok. pullmoll did some research resetting on either the leading edge or the trailing edge of the reset pulse.
This would be worth revisiting as it would make the propeller easier to access if you could program it with a $2 USB serial cable.
I think Garreth posted a way to hack some of the inexpensive USB to serial cables to use them with the Prop. I'll see if I can find the thread.
Thanks, but I think Cluso99 has a better solution. He's the one (not Garreth, though Garreth does a lot of cool stuff) who posted a thread about an inexpensive Prop Plug alternative.
Someone told me about this while we were watching the video stream from the last UPEW.
BTW, I doubt I was the first to make a Prop Plug from an USB Prop Protoboard. I'd read mention of it on the forum and read that someone had pictures and instructions, but I've never seen the pictures or instructions.
I bought one of these:
http://www.ebay.co.uk/itm/Mini-USB-serial-FT232RL-TTL-5V-3-3V-Arduino-Duemilanove-Mega-UNO-bootloader-/370579517002?pt=US_Parallel_Serial_PS_2_Cables_Adapters&hash=item564842ae4a
Is it likely to be usable with a Prop?
Cheers
Richard
My guess is it would be. I haven't ever used a non-Parallax USB to serial interface with a Prop myself.
To Clarify I either need a RS-3232 Serial and a Serial to usb connector which has a certain chip set,
or a connector for a prop plug and the plug it's self...
Is a RS-3232 Serial the same as a VGA video out port? - if so, surely I can feed video out of it once the propeller boots? -keeping ports minimal.
A big problem I will have with the C64 emulator is indeed the initial simulation - however if I take apart an open source emulator and rewrite it to run on the Propeller...
I don't know it it's feasible with such small amount of memory.
And whats SD cards? I though the propeller can read to a maximum of 64K EEPROM? so how does the SD work?
I may just get a starter kit and a prop plug and forget about building my PCB at the moment.
EDIT : I also have an old serial Keyboard which I plan to hook up directly to the board - whith a little imagination I could mount the Board on the under side of the Keyboard - just like the orginial C64 - there isn't enough room however to install it into the case
Short answer would be "Yes" as it has the FT232 chip. You may still need the capacitor, resistor and transistor to generate the reset pulse (eg 0.01uF, 33k and BC549).
RS232 serial needs two propeller pins. VGA needs 8 propeller pins. The great thing about the propeller is you can reconfigure pins in software to do all sorts of different things. TV for instance needs 3 propeller pins and 3 resistors.
SD cards need 4 propeller pins and 4 resistors. That gives you gigabytes of memory storage. Also take a look at what the boffins are doing with GCC. They use a cache which stores frequently used blocks of code and in combination with an SD card you can have programs gigabytes in size, but only need the 32k of the propeller. It means you can run huge programs. This is all very new and hasn't been explored much yet. And the nice thing is that this works with a whole range of standard propeller boards - any board with an SD card in fact. So I'd suggest you start with one of the existing boards eg one that has an SD card.
Serial keyboards work on the propeller. 2 propeller pins and 4 resistors.
So the only additional download components are either the 3 transistor circuit or a max3232.
If finances are an issue this can be a practical alternative to the propplug.