Hey guys,
I’m looking to build a very cheap POV device for a Human Powered Vehicle (basically a recumbent bicycle) if you want a bit of an idea on what I’m planning on putting this on then go here **broken link removed**.
Anyway, I need a little help designing it.
I want the LED's to be mounted either vertically on the body of the vehicle OR along the spokes of a wheel, however, I am not sure which will be better, as I don’t know whether its mounting position will effect the speed we must be travelling at to get clear "images" (text), whether the LED’s are at risk of serious damage (the vehicles roll frequently) and whether the weight will have a significant effect on the balance of the wheel.
So my first question is where do you think the best mounting point is (body or wheel)?
I have been doing some research looking at various similar projects, in particular https://www.ladyada.net/make/spokepov/index.html, which uses a Serial to Parallel Latch, what does this do, and is my project likely to need one?
The main functions I want to incorporate into this device are periodic display of team name (and possibly school name as well), periodic display of current speed, periodic display of total distance/lap count and maybe some team sponsors too.
If the laps are counted I want to be able to store them before power down and be retrievable from a PC (although this isnt a must-have)
These are a few constraints that I think I will have to follow to make sure it is cheap, effective and allowed to be mounted.
Constraints:
Small
Lite
8 LED’s (or a few more) (must not be Red, should avoid White this is to keep it within the competition rules)
Smallest number of components possible (to keep the size/weight/cost down)
Batteries last ~25 hours (length of the race is 24, lights on for 12 6pm-6am)
Cheap < AU$20 (or as close as possible)
Auto adjust for speed (to keep the display clear and consistent)
Must be completed and debugged by 5th of September 2007 (at the very latest)
Easy to program/reprogram
Operational display between 18Km/h and 40Km/h (lower speeds too, if possible)
I plan to get my MCU for free using samples, however I’m not sure which one to go for, must be sampleable, must have enough pins and must be fast enough to be able to monitor speed and update display. The one that seems to be most commonly used is the ATtiny2313, is this a good MCU to use? any better suggestions?
I don’t have a programmer apart from a PICAXE programmer, and I want to be able to do in-circuit programming if possible.
I also need to choose a language to program it in, I don’t know ASM or C (although I think I could pick up C) and i have never used Basic on a MCU, although i do use VB6 and have used PICAXE Basic (neither of which count for much)
Are there any disadvantages/advantages to using Basic over C?
Lastly, now that I think I have worked out my design specs, where do I start in building the circuitry?
Thankyou
PS Sorry for the long post.
I’m looking to build a very cheap POV device for a Human Powered Vehicle (basically a recumbent bicycle) if you want a bit of an idea on what I’m planning on putting this on then go here **broken link removed**.
Anyway, I need a little help designing it.
I want the LED's to be mounted either vertically on the body of the vehicle OR along the spokes of a wheel, however, I am not sure which will be better, as I don’t know whether its mounting position will effect the speed we must be travelling at to get clear "images" (text), whether the LED’s are at risk of serious damage (the vehicles roll frequently) and whether the weight will have a significant effect on the balance of the wheel.
So my first question is where do you think the best mounting point is (body or wheel)?
I have been doing some research looking at various similar projects, in particular https://www.ladyada.net/make/spokepov/index.html, which uses a Serial to Parallel Latch, what does this do, and is my project likely to need one?
The main functions I want to incorporate into this device are periodic display of team name (and possibly school name as well), periodic display of current speed, periodic display of total distance/lap count and maybe some team sponsors too.
If the laps are counted I want to be able to store them before power down and be retrievable from a PC (although this isnt a must-have)
These are a few constraints that I think I will have to follow to make sure it is cheap, effective and allowed to be mounted.
Constraints:
Small
Lite
8 LED’s (or a few more) (must not be Red, should avoid White this is to keep it within the competition rules)
Smallest number of components possible (to keep the size/weight/cost down)
Batteries last ~25 hours (length of the race is 24, lights on for 12 6pm-6am)
Cheap < AU$20 (or as close as possible)
Auto adjust for speed (to keep the display clear and consistent)
Must be completed and debugged by 5th of September 2007 (at the very latest)
Easy to program/reprogram
Operational display between 18Km/h and 40Km/h (lower speeds too, if possible)
I plan to get my MCU for free using samples, however I’m not sure which one to go for, must be sampleable, must have enough pins and must be fast enough to be able to monitor speed and update display. The one that seems to be most commonly used is the ATtiny2313, is this a good MCU to use? any better suggestions?
I don’t have a programmer apart from a PICAXE programmer, and I want to be able to do in-circuit programming if possible.
I also need to choose a language to program it in, I don’t know ASM or C (although I think I could pick up C) and i have never used Basic on a MCU, although i do use VB6 and have used PICAXE Basic (neither of which count for much)
Are there any disadvantages/advantages to using Basic over C?
Lastly, now that I think I have worked out my design specs, where do I start in building the circuitry?
Thankyou
PS Sorry for the long post.