If you need assistance, please send an email to forum at 4hv dot org. To ensure your email is not marked as spam, please include the phrase "4hv help" in the subject line. You can also find assistance via IRC, at irc.shadowworld.net, room #hvcomm.
Support 4hv.org!
Donate:
4hv.org is hosted on a dedicated server. Unfortunately, this server costs and we rely on the help of site members to keep 4hv.org running. Please consider donating. We will place your name on the thanks list and you'll be helping to keep 4hv.org alive and free for everyone. Members whose names appear in red bold have donated recently. Green bold denotes those who have recently donated to keep the server carbon neutral.
Special Thanks To:
Aaron Holmes
Aaron Wheeler
Adam Horden
Alan Scrimgeour
Andre
Andrew Haynes
Anonymous000
asabase
Austin Weil
barney
Barry
Bert Hickman
Bill Kukowski
Blitzorn
Brandon Paradelas
Bruce Bowling
BubeeMike
Byong Park
Cesiumsponge
Chris F.
Chris Hooper
Corey Worthington
Derek Woodroffe
Dalus
Dan Strother
Daniel Davis
Daniel Uhrenholt
datasheetarchive
Dave Billington
Dave Marshall
David F.
Dennis Rogers
drelectrix
Dr. John Gudenas
Dr. Spark
E.TexasTesla
eastvoltresearch
Eirik Taylor
Erik Dyakov
Erlend^SE
Finn Hammer
Firebug24k
GalliumMan
Gary Peterson
George Slade
GhostNull
Gordon Mcknight
Graham Armitage
Grant
GreySoul
Henry H
IamSmooth
In memory of Leo Powning
Jacob Cash
James Howells
James Pawson
Jeff Greenfield
Jeff Thomas
Jesse Frost
Jim Mitchell
jlr134
Joe Mastroianni
John Forcina
John Oberg
John Willcutt
Jon Newcomb
klugesmith
Leslie Wright
Lutz Hoffman
Mads Barnkob
Martin King
Mats Karlsson
Matt Gibson
Matthew Guidry
mbd
Michael D'Angelo
Mikkel
mileswaldron
mister_rf
Neil Foster
Nick de Smith
Nick Soroka
nicklenorp
Nik
Norman Stanley
Patrick Coleman
Paul Brodie
Paul Jordan
Paul Montgomery
Ped
Peter Krogen
Peter Terren
PhilGood
Richard Feldman
Robert Bush
Royce Bailey
Scott Fusare
Scott Newman
smiffy
Stella
Steven Busic
Steve Conner
Steve Jones
Steve Ward
Sulaiman
Thomas Coyle
Thomas A. Wallace
Thomas W
Timo
Torch
Ulf Jonsson
vasil
Vaxian
vladi mazzilli
wastehl
Weston
William Kim
William N.
William Stehl
Wesley Venis
The aforementioned have contributed financially to the continuing triumph of 4hv.org. They are deserving of my most heartfelt thanks.
Registered Member #27
Joined: Fri Feb 03 2006, 02:20AM
Location: Hyperborea
Posts: 2058
Doing USB in software is not impossible and the 16F84 might just be fast enough. The amount of program memory and RAM is on the low side but it is probably possible to fit it. You only need to do 1.5Mbit/s to do USB.
Registered Member #477
Joined: Tue Jun 20 2006, 11:51PM
Location: Seattle, WA
Posts: 546
Uzzors wrote ...
I've been looking for a DIY USB PIC programmer, but I haven't found anything but commercial products. Is there a DIY programmer out there?
Only barely DIY: Get a PICKit 1 and solder a ZIF socket onto the protoboard that's attached. That's what I did, and it's been a fine programmer for years. Unless the programmer itself is something you want to build, the idea of a DIY programmer is kind of a strange thing to me when the non-DIY sort are so damned cheap nowadays!
On the USB thing in general: Going to PIC18 just to get FLASH and USB in one package and then futzing around with all the various USB firmware floating around out there is good challenge, even for those who have been hacking around with PICs for some time. One option you might consider, if you're ok with "pseudo-DIY" USB, is the FT245R by FTDI. It's a USB-to-parallel FIFO IC with free drivers for several OSes. Looks like it would be a total breeze to wire to a PIC, and then it's basically all over. They also make the UM245R, which is a DIP evaluation module complete with USB port. I've been about to order one for a little while now Just waiting for that USB-needing project to come along:
The FT245R's are a couple of bucks, but are only available in surface-mount packages. The UM245R evluation module is ~$20 (USD), however it's hopelessly convenient as a way to prototype USB devices on a breadboard. Of course $20 is more than you'll pay for a used PICKit 1 or 2 on eBay
Registered Member #191
Joined: Fri Feb 17 2006, 02:01AM
Location: Esbjerg Denmark
Posts: 720
I guess I'm lucky/a different generation, I have access to the ICD2 puck from microchip. And I only wright in C, never touched a single line of assembly.
right now, I'm working on a CAN network for the university's solarcar using teh 18f458 with MCP2551.
Registered Member #477
Joined: Tue Jun 20 2006, 11:51PM
Location: Seattle, WA
Posts: 546
Electroholic wrote ...
I guess I'm lucky/a different generation, I have access to the ICD2 puck from microchip. And I only wright in C, never touched a single line of assembly.
right now, I'm working on a CAN network for the university's solarcar using teh 18f458 with MCP2551.
Just depends on what you're doing. Assembly on the PIC12/16 devices is about the easiest assembly coding you'll ever do, especially because most C programs written for the PIC12/16 still mainly seem to be long sequences of register assignments that translate line-for-line into assembly anyway If you need precise timing, however, you'll eventually warm up to the idea of using assmbly, simply because it's easy to make timing mistakes in C, or otherwise subject yourself to implementation details of the compiler. For example, compilers must assume that the order in which you make register assignments is important, and yet because registers exist in different "banks" in the PIC, the order in which you make assignments may greatly influence the amount of code emitted. There are other pitfalls too. I've never used the PIC18/24 devices, however I know they have about 2x the instruction set of the PIC12/16, so I'm sure the difference in "comfort" between C and assembly is definitely greater on the more complex devices.
Registered Member #477
Joined: Tue Jun 20 2006, 11:51PM
Location: Seattle, WA
Posts: 546
BlackPlasma wrote ...
Does a USB > Serial converter module count as a PIC programmer? =P
No. But I was referring to the USB > parallel converter, not USB > serial The FT245R in "bit bang" mode is about all you need to do ICSP via USB. The USB-to-parallel FIFO ICs are awesome for a lot of reasons.
Registered Member #95
Joined: Thu Feb 09 2006, 04:57PM
Location: Norway
Posts: 1308
I'm about to start building the "Brenner8" which Mikkel found. Not having taken German in school, I have to use babelfish so it's pretty unclear what to do. Here's the babelfish translation, everything you need to know should be on that page.
Do I need an external programmer to program the 18F2550 with the bootloader first, then build the circuit, and finally program the 18F2550 with the firmware? Or is an external programmer even needed?
Registered Member #95
Joined: Thu Feb 09 2006, 04:57PM
Location: Norway
Posts: 1308
It's quite the professional programmer, with it's own driver and all, I felt like I had bought a commercial product! Everything seems to be working nicely, but the Vpp voltage is way too low. When I use the graph function the voltage hardly rises no matter what duty cycle is used. It never leaves 5V... I'm going to check things over carefully so while I'm doing so; I used a physically small inductor for the boost inductor with 20 ohms of DC resistance, is it the problem? It's the size of a 1/2 watt resistor. What kind of inductor did you use Anders? I used a BAT43 diode which is what is specified in the schematic, and a BC337 transistor.
This site is powered by e107, which is released under the GNU GPL License. All work on this site, except where otherwise noted, is licensed under a Creative Commons Attribution-ShareAlike 2.5 License. By submitting any information to this site, you agree that anything submitted will be so licensed. Please read our Disclaimer and Policies page for information on your rights and responsibilities regarding this site.
DIY USB PIC programmers?
Just waiting for that USB-needing project to come along:
