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Topics - voidptr

1
Client software / Pulse Counter wrong transistion.
I just found this ... it might be fix tho ...

When I select Channel 0  I get  transistion up 0 down 1
When I select Channel 1  I get  transistion up 1 down 0    (wrong)

I'm using  0.9.7 release before the SP1, I didn't have time to install the last version.
EDIT: same behavior with 0.9.7SP1
[attachment=0]
3
Bus Pirate Support / Homemade 2 wires protocol or some addons to the 2wire proto
here my late night toughts :-)

I got a board with that TM1638 chip,
the datasheet shows  a pretty simple 3 lines protocol
it needs a CS (Strobe STB, they call it ) chip select line
a clock CLK line and a data DIO line.

[attachment=1]

so basicly it is a 2 lines (CLK Data) protocol .
I I told myself, my buspirate surely can do that ....

so CS (STB) will be set with the Aux pin.
and well it looks near a 2wire  sub case...
we don't need  Start or Stop functions , we need just clk and data.

I got few of those homemade Clk Data protocols, usually basically clocking a shift register...

so  the only problem here is their clock is inverted ...
but anyways they always set Data before going low with the Clk, and latching it with the rising up.

but huh !  no option to inverted the clock from the bus pirate...

2WIRE>a 0x42 r:4 A     
should have work

so my temporary solution was to put an inverter after the BP clock
so CS orange
BP Clock red
BP clock inverted purple
Data blue

[attachment=0]

even if inverting the clock move the rising latch, it is exactly what they want...
so here sending a command to read all switches.

2WIRE>a 0x42 r:4 A                                                             
AUX LOW                                                                       
WRITE: 0x42                                                                   
READ: 0x80 0x80 0x80 0x80                                                     
AUX HIGH                                                                       
2WIRE>

so what do you think about

adding an inverted clock option setting, and also why not a data inverted too :-)

:o)
4
General discussion / someone made heat sink for ic stack ?
Ok ,
 
I got this motor shield, with flimsy L293D hbridge  :op 
I'm planning to stack 2 L293D together to have more current, it should works fine ...

But I also want to include some kind of  heat sink in the stack,
anyone here did this before and came with cool nice designs ? ;-)

I have few chunks of black anodized aluminum that I plan to use for that .
 :-)
5
Bus Pirate Support / new display format 'cause I'm lazy :o)
Of course I'm a lazy noob :o)
so there is a suggestion to help me and maybe others people who don't want to make conversion on a paper sheet :o)

a more versatile display function
let say we got this in i2c
[0xD0  0x00 [0xd1 r r] 

it could be so nice to chose the display format like this
[0xD0  0x00 [0xd1 rx rd]
where we add after the 'r' a display format 
r still display the default mode
rx  display hexadecimal
rb display binary
rd display decimal

:o)

i took a peek at the code and it seems not to difficult to implement and it could be really useful ...

what do you thing about this :o)
6
General discussion / Pads, got some really weaks !
I already solder few headers on pads and drag some other boards around without any problems...

but, I just got this ebay board and got a bad surprise,  I soldered the header, did not overheat it I'm pretty sure.
connected few wires and plug them on a breadboard ...
while moving the breadboard around all pads of the ebay board  broke off ...

duh !  im thinking the quality on the pads is way low,  copper layer should not unstick so easily ...

do I miss something ? I'm still pretty noob :-)
I was planing to incorporate pads in my future board design to make some kind of card edges ...
are they going to peeal away ?

7
General discussion / wish me luck, I'll try to solder this small cap !
I will try to solder this 0805 cap on those pads, who seems to be made for 0603 ...
Board's caps are all 0402, I'm lucky they think a bit about the poor noob who
will solder things they made the pads bigger ...

So any hint before I burn my board ? :O)

8
Project logs / PIC32 dip on blade board :-)
hey ! 

i moved my noob pcb project here :o)

i'm thinking to design an PIC32 DIP on a blade board,
i took a jump-start from Dangerous Prototype PIC32 board and make few changes,

i used a mini B usb connector in dip format,  i have a bunch of them here ...
i want to have a blade type board, with all the pins ordered.

it is me first board project so be gentle,
i'm currently learning eagle and all other stuff ...

here my first step :
[attachment=1]
[attachment=0]

i think i found the general placement ...
eagle routing seems to be kindof dumb sometime, i think i will have to route by hand ...

? question
i think i should not have any trace going under the xtal to have less interference
is it ok to have traces on the bottom side ?

all advices are welcome !
9
General discussion / Eagle parts for noob :-)
I thought it could be good to have a thread where we can share some basic Eagle stuff ...

there's DP tutorial here for ref
http://http://dangerousprototypes.com/docs/Dangerous_Prototypes_Tutorials#Cadsoft_Eagle

Noob starts here :o)

I included  .sch/.brd files of a mini usb through hole I'll need to used  ,  (both resistors are there only to have something to wire to as tests)
here the same item on ebay
http://http://www.ebay.ca/itm/170742316555?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649

on the generated board do I have to do something more for the usb connector pads ?,
I means just placing the connector there will tell the pcb builder to make the pads and to drill holes for them ... right ?

and my mini usb connector has an ID pin, should i just let it unconnected ?

:-)
10
General discussion / pic18f2550 with microchip USB demo
hi :-)

anyone has an "hello world" or a "serial usb echo" project  already built for the pic18f2550 using the lastest microchip USB stack .
a fast look at the already build demo doesn't show one for this pic...

i know im lazy :o)
11
General discussion / 5v to/from 3.3v level ic suggestions ...
i'm looking for suggestions for level converter ic ,  if possible available in  dip and SMD.

im waiting on few BSS138  mosfet to try this solution who seems to be a standard for bidirection...
but is this the best way to go ?

right now i did my matching level between an Amega328 spi interface and a 23K256 SRAM with resistor dividers and diodes, this is good for more than 1Mbits, that is fine with my prototype.

13
Project logs / a silly Joule Thief :o)
here my first try at a joule thief :-)

it seems pretty good,  i started with and alkaline at 0.9V and drained it during the last week, to 0.48V ...
this seems to be the best it can do ...


i used circuit B from
http://http://talkingelectronics.com/projects/LEDTorchCircuits/LEDTorchCircuits-P1.html
with modification on the toroid, mine has a lot less winding than the original circuit ...

i really need a scope to see what is happening and to try few tweaks.

is there a way to drain more juice from those old batteries ?. 
i guess some kind of multistage with some caps (miller engine !?)
of course it will not light a led but it might be good to pulse it from time to time...

any suggestion ?  :o)
14
General discussion / pic12F(LF)xxxx sink source pin current ...
hi, here another noob questions :-)

im currently using pins of pic12F1840 to drive a circuit every thing is fine when at Vdd = 5V
but my circuit is not working at low Vdd = 2.5, not enough current flowing
but it can be my fault bad choice of components with to much of impedance ....

EDIT:  the pic is running fine at low V, but digital pins dont seems to sink or source
alot of current  ...

i need to know if the current source sink max current for a pin (around 20mA i guess) is constant when Vdd go low, around like 2AA or 2.5V or on the complete space Vdd (2.3v to 5.5v) vs Clock diagram.

is it the same current specs with the LF version ? Vdd (1.8v to 3.6v)
i think i will have sacrifice a pic to find that out ...

is there some other 12Fx  8pins pic with more than 20mA current available ?

thanks :-)
15
General discussion / Where can I find this part thread !
Darn ... noob question here  :o)

where  can i find this kind of tall header, twice the size of normal male header...
ebay source (inexpensive Chinese) will be the best  ...  "they" never saw this at my locals stores !