OBC, Suggestion for your book, use the new mlx90614 ir thermometer sensor and have it display on the led display. If you run off a battery it makes a fun toy to walk around with. I can give you the code I have that does this but it uses the sensor directly rather than uses the parallax sensor but if you which pauls driver driver for mine it should work.
Oldbitcollector said...
Excellent tip! I just got a few of these in today. Not sure how I lived without this.
Thanks
OBC
Don't mention it....wish I had a way to get power on the three wires going into the weatherhead on our house!
Still without power (2 weeks now) here in Houston. More fortunate than many, but still running off a generator intermittantly!
One thing that would be nice to add to the PPDB is a way to tap into the input power. I am running motors off the L293D on the PPDB but to do that I have to split the motor voltage out before supplying the PPDB. Having a way to get to the power in so it can be feed to the motor voltage supply would be good.
By putting a motor voltage supply onboard the PPDB would probably involve something like the HB25, and so raise the price (which Parallax seems destined to fight for eternity)
I am just talking about an connection to the incoming power not a power regulator. Currently I connect a battery to the PPDB the cable splits the power into 2 wires, 1 to the PPDB input and 1 to the L293D motor voltage input. Whereas having a screw connecter in parallal to the 2.1mm power socket would allow a wire to run from this to the L293D motor voltage.
I understand time-swapping the LED displays so they can display different information on each. However, if all 6 LED displays are used, doesn't that mean that each only gets a 1/6 duty cycle? If so, doesn't that mean that they'll all be dim? Certainly the swapping is happening way faster than persistence of vision; however, the fact remains that each is only getting a 1/6 time slice. I saw some of the pictures on this thread, and it looks like they are bright enough, but I don't understand why. Can someone explain why it works?
I have an older pcb which has 6 seven-segment digits and 28 keypad switches. This design was prior to the Prop and uses a PIC. The keypads are scanned as each digit is displayed one at a time. The LEDs are green and quite bright and more than adequate. Prior to updating one digit, the previous digit is turned off while the keypads are scanned, and when the scan cycle is complete, the next digit is turned on. Update rate is about 80 times/second.
The keypad scan operation, when it detects a pressed key, sets a flag and stores the row/column info. If a scan finds a key still down for more than 10 times without changing, it declares a valid debounced key. It then processes the row/column info for generating the 'pressed key' code and further processing occurs. When processing is done, the next digit is displayed. No flashing of LEDs during a key press as the display and key scan are separate; scan occurring while all LEDs are off.
Might sound a bit convoluted, but simplified the design considerably. Maybe if one has older, say RED LEDs, the dimming might be more pronounded. Segment drive and keypad scan uses one 8-bit port; six lines for Digit control and 4 lines to read keypad 'column' code. More than asked.
I believe the main reason is human vision is non-linear . If the pulse rate is right, the brightness can be perceived to be peak brightness rather than average.
Do I have something wired wrong, or is there an extraneous segment lit for the digit '4' in ppdb_numtest? (You'll have to increase the delay to see.)
The original code is:
if num==4
DIRA[noparse][[/noparse]0..7] := %10101101
but that lights the bottom segment. I changed it to this:
if num==4
DIRA[noparse][[/noparse]0..7] := %10001101
and now it looks right.
BTW, I posted a general-purpose seven-segment controller object to the object exchange last year: obex.parallax.com/objects/142/. I'd like to expand it to work with all the segments on the PPDB, but time is really tight right now.
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔ OS-X: because making Unix user-friendly was easier than debugging Windows
Comments
Tim
I'm actually working on this using a DS1620 chip. [noparse]:)[/noparse]
Great minds think alike.. [noparse]:)[/noparse]
OBC
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
New to the Propeller?
Getting started with a Propeller Protoboard?
Check out: Introduction to the Proboard & Propeller Cookbook 1.4
Updates to the Cookbook are now posted to: Propeller.warrantyvoid.us
Got an SD card connected? - PropDOS
Also in terms of a battery, I got 1 of these a while ago
http://cgi.ebay.com/A30-8V-Rechargeable-Lithium-Battery-For-spy-Camera_W0QQitemZ230288453628QQcmdZViewItem?_trksid=p3286.m20.l1116
it works great and the supplied plug fits the ppdb and proto board.
Edit: I didn't get my battery from here, but they no longer sell it and this looks identical.
Post Edited (Timmoore) : 9/20/2008 10:51:31 PM GMT
Don't mention it....wish I had a way to get power on the three wires going into the weatherhead on our house!
Still without power (2 weeks now) here in Houston. More fortunate than many, but still running off a generator intermittantly!
Lil'Joe
By putting a motor voltage supply onboard the PPDB would probably involve something like the HB25, and so raise the price (which Parallax seems destined to fight for eternity)
I have a PPDB coming so I just went through this thread and downloaded all the code and re-read everything. Thanks so much for sharing all this!
Can't wait to play.
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Whit+
"We keep moving forward, opening new doors, and doing new things, because we're curious and curiosity keeps leading us down new paths." - Walt Disney
Thanks!
- Earl
I have an older pcb which has 6 seven-segment digits and 28 keypad switches. This design was prior to the Prop and uses a PIC. The keypads are scanned as each digit is displayed one at a time. The LEDs are green and quite bright and more than adequate. Prior to updating one digit, the previous digit is turned off while the keypads are scanned, and when the scan cycle is complete, the next digit is turned on. Update rate is about 80 times/second.
The keypad scan operation, when it detects a pressed key, sets a flag and stores the row/column info. If a scan finds a key still down for more than 10 times without changing, it declares a valid debounced key. It then processes the row/column info for generating the 'pressed key' code and further processing occurs. When processing is done, the next digit is displayed. No flashing of LEDs during a key press as the display and key scan are separate; scan occurring while all LEDs are off.
Might sound a bit convoluted, but simplified the design considerably. Maybe if one has older, say RED LEDs, the dimming might be more pronounded. Segment drive and keypad scan uses one 8-bit port; six lines for Digit control and 4 lines to read keypad 'column' code. More than asked.
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Harley Shanko
The original code is:
if num==4 DIRA[noparse][[/noparse]0..7] := %10101101but that lights the bottom segment. I changed it to this:
if num==4 DIRA[noparse][[/noparse]0..7] := %10001101and now it looks right.
BTW, I posted a general-purpose seven-segment controller object to the object exchange last year: obex.parallax.com/objects/142/. I'd like to expand it to work with all the segments on the PPDB, but time is really tight right now.
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
OS-X: because making Unix user-friendly was easier than debugging Windows
links:
My band's website
Our album on the iTunes Music Store