small problem we cannot buka to tengok or test with multimeter because we dont have the equipment or the boards to test it so basically its just sitting in our office doing nothing...
the module was bought from a factory as a dev kit and we didnt realise that the connector is not the usual 4/5pin UART connector until it arrived..

Just make a cable to connect to the board. Then you can check the connections from there (on the cable).

is there any easier way to make pcb board?
i mean like last time there's a thread selling DIY PCB paper..
but i just cant find it anymore here..
can anybody suggest to me how to make pcb board easier..
thanks in advance.. =)

Use the toner transfer method. Equipment required is just a laser printer, and/or photostat machine (or simply use any available photostat service). You search and/or look it up on the internet...

Thanks =)

guys, need some help...anyone knows what these connectors are called??

Looks like a PCB header connector. Example: RS Components > Connectors > PCB Connectors > PCB Headers JST ER - Connector, multipole PCB use, SM12B-SRSS-TB, SH series...

actually shipped some Molex connectors before you posted..luckily it fits ..but i need to get wires that are in the 28 - 32 AWG size as well as crimper for the terminals.. should have shipped them with RS-Components but since i also need to get some rocker switches..might as well go down to jalan pasar or puchong..gotta smack myself one day...

one more question, what is the correct way to redirect a circuit? i have (multiple) one data line which i want to switch between 2 lines...google seems to show that a 1 to 2 demultiplexer might work..any suggestions??
the circuit will require 3.3V so I have to use a logic level converter since i can only provide at 5V

Are those data lines bi-directional or uni-directional? What type of selection (switch) method used? Is it controlled via logic signal, MCU or manual?

i would prefer bi-directional and will most probably be a logic signal..
thought maybe a 4 to 8 line demultiplexer might work..unless i got the logic of it wrong..

If you have around 4 I/O lines, then look at either CD4066 or 74HCT4066. And if the signals are all digital/logic type plus have a direction control signal then you could try using 74LS245 (for TTL) or 74HCT245 (for CMOS), both has 8 I/O lines.

This post has been edited by lex: Oct 1 2013, 11:49 AM

hey lex, thanks for your help...really appreciate it...
i am not sure if my idea is correct, but let me explain it..
i have an arduino board <-> a storage device <-> another arduino board. my intention is for the 2 boards to share the storage device, though not simultaneously.
so my ideas was for the SPI pins from the storage device to be connected as the input and the SPI pins from the 2 boards be connected to the outputs. the primary board will be the one in charge of switching the digital switch when it does not need the storage...

I don't think you can do that as there will be clashes (two master devices sharing the same I/O lines). Better methods are...

#1. Simply create a simple switch matrix (using the I.Cs described earlier) to select which Adruino board will be able to connect to the storage device.

#2. Setup the second Adruino board as a slave SPI device. Create a communications protocol to communicate between both Adruino boards, which the first Adruino board will act as an storage interface (fetch data from the storage device on demand, and send to second Adruino board).

#3. Create a simple communications link with both Adruino boards (can be serial based). The first board will connect directly to the storage interface (just as mentioned above, fetch data for the second Adruino board on demand).

Of course, methods #2 and #3 will mean extra programming...

the idea is actually to be like the method 1...
what i meant was the SPI pins from the storage be connected to the 4 input pins from the IC and the 8 output pins will be connected the 8 SPI pins..no sharing of pins...the entire switching will be for the 4 pins...no sharing of pins at all..so the conflict wont happen..

Well, that would the simplest method of course. Just select between which board's I/O lines to switch to...

problem is i need to find a DPDT I/C only...

You can't figure our how to use those I.Cs? For example, that CD4066 is so simple. Either use a single control line with an inverter (either a simple transistor or a CMOS logic I.C with inverter gates), or just use 2 control lines to select which CD4066 to switch on...

or use an ADG888

Yes, you can use that. But do note that its not as common as CD4066 or 74HCT245, which you can even buy at any electronic stores like those at Pasar Road. Plus its SMD, thus not really prototyping board friendly (ie. have to make your own PCB usually) and not simple to swap out if have problems. With the other two I've mentioned, can use either strip boards or breadboards, as well as I.C sockets...

so if i were to use them, i need to connect the 4 pins from my storage to the CD4066 and each SPI from the board to the specific CD4066. And then using an inverter(NAND gate) connect it from one board to the I/Cs..only with one before the inverter and one after..right?
but for the directs, it seems i need to specify the directions..