Kool Serial LED display.

[fernando_g]

There are instances where a LCD display module may not be desired or required.
In that instance, one may use 7 segment LED displays, but one requires plenty of I/O pins to do it.
Even with helper circuits like the 4511 one needs 4 pins for the BCD number plus additional pins for multiplexing the digits.
Browsing the web, I found this serial LED module. Way Kool!

http://www.rentron.com/SLED-C4.htm
The only problem I see with a PICAXE is the minimum 9600 baud requirement.

 

[SilentScreamer]

9600 baud can be done with any PICAXE running at 8Mhz I believe so it isn't much of a problem.

 

[fernando_g]

You are absolutely correct!

 

[manuka]

An interesting one (although at US$34 maybe a tad pricey?), which could appeal compared with rolling your own 4511 etc version.The retro look & brightness of 7 segment LEDs often suits niche applications of course- public outdoor displays of time/temperature particularly.

I'd recently been pointed to a PIC project => http://www.romanblack.com/led_none.htm using a small surplus display from Australian outlet Oatley Electronics => http://secure.oatleyelectronics.com//product_info.php?cPath=64&products_id=321&osCsid=f481db0eee8690070b1589c373cdc20b Stan

 

[tiscando]

08m baud

But the 08m does not support 4800 baud at 4MHz (in PE in 08m mode, n4800 is an unknown symbol), but how does it receive downloads from the PC?

 

[Andrew Cowan]

setfreq m8

pause 2000      'this acually pauses for 1 second
serout n2400      'this is actually at 4800 baud
serout n4800_8   'telling it that it is at 8MHz means this will also output 4800 baud

@tiscando - 4800 doesn't work, but n2400 will actually be at 4800. Alternativly, use n4800_8. However, this does mean it can't reach 9600 baud - 4800 is the upper limit. You do it with a 14M, however.

Andrew

 

[tiscando]

So basically, the 08m sets it's freq to m8 before receiving a download?

Cannot do n/t9600_8 or n/t4800_4, but can do n/t4800_8.

 

[MORA99]

Sure electronics have a few similar boards, these are controlled by shiftout.

http://www.sureelectronics.net/goods.php?id=133

 

[GreenLeader]

Sparkfun have got a serial 4x7-segment display for about $15. Got one on order, just waiting for it to come...

 

[hippy]

So basically, the 08m sets it's freq to m8 before receiving a download?

Cannot do n/t9600_8 or n/t4800_4, but can do n/t4800_8.

SERIN and SEROUT have a maximum baud rate of 2400 at 4MHz, which when over-clocked to 8MHz gives 4800 baud.

SERTXD has a baud rate of 4800 at 4MHz which becomes 9600 at 8MHz. By using SERTXD the PICAXE-08M can transmit at 9600 baud via pin 0 ( leg 7 ) but it has no means to receive at 9600 baud.

At power-on reset the 08M configures its internal oscillator to 4MHz and downloads at 4800 baud; SERIN and SEROUT baud rates have no relevance to that.