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.
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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
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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 :-)
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 ...
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 ?
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 ...
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 ?
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'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.
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...
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 ?
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 !
