DINx1 with 74LS165N ?

[demym]

Hi,

i've prepared a DINx1 module on my breadboard... I am using an 74LS165N instead of the 74HC165 shown in the mbhp_dinx1.pdf document..

Two questions:

1) is the 74LS165N IC equivalent to the 74HC165 ? (my store man told me that it was); i found the datasheet for this IC, and pin map seems to be identical to the 74HC, with the only difference that pin 9 on 74HC (QH) seems to be an input, datasheet for LS175 instead calls that pin Serial Output from Last State...  (Q7)

2) My DINx1 doesn't work, i have no response in DIN_NotifyToggle when i press the button (i have only connected one button to I0 of the IC, and made all the other non-data connections, as 5V with 100nF condenser, 10k resistor on SER, etc..); do i have to specify somewhere in my code that i am using a DINx1 ?

My circuit on the breadboard seems to be correct...

What am i missing ?

Thanks in advance

[Screaming_Rabbit]

Sorry, I don't have enough time to check the datasheets right now, but so far I can tell you, that Pin9 on the 74HC is one of the serial outputs and not an input.

Greets, Roger

Perhaps I fill find the time to check the datasheets, later tonight when I got home.

[johnh]

1) is the 74LS165N IC equivalent to the 74HC165 ? (my store man told me that it was); i found the datasheet for this IC, and pin map seems to be identical to the 74HC, with the only difference that pin 9 on 74HC (QH) seems to be an input, datasheet for LS175 instead calls that pin Serial Output from Last State...  (Q7)

These chips should be logically equivalent.  Pins 7 and 9 are serial outputs. 

---john.

[stryd_one]

LS vs HC is Low Power Schottky vs Highspeed CMOS. The difference is in the logic levels.

Search Results show that stryd one likes to repeat himself. :D

Edit: Would help if I answered the question! To quote from an abovelinked hit:

The short version is: CMOS will drive TTL, but TTL will not drive CMOS.

PIC pins drive peripherals at CMOS levels, so they will drive the AIN. So yes, it will work.

But no your store guy was wrong, they aren't the same.

[johnh]

The difference is in the logic levels.

I almost said 'functionally' equivalent but to me that implied that the electrical characteristics were the same.  I used 'logically' equivalent to mean that they work the same way.  English is a horrible language!  :P

[stryd_one]

Hahahah I didn't even notice that! Well they are logically the same, in that the logical truth tables are the same. But not logically the same in that the electrical logic thresholds are the same. You're right this language sucks We need MB-esperanto! :D

[demym]

Well, good to hear that the IC is a correct one. Thx

But my simple DINx1 on a breadboard doesn't work...When i press the button nothing happens in DIN_NotifyToggle...

Is there a troubleshooting, as for the Core ? I seem to have right voltage levels..

Also, of the 8 data lines, i have connected only one (I0).. the other ones are not connected, should i connect them (10k pull-up resistor + grounding switch) to test functionallity ? Apart from the data lines, pin 7 (QH#) of IC is left open, as for the schematic of DINx1. The other ones are all connected where they should..

Thanks guys

[philetaylor]

Hi.

It looks live everybody else ignored the last bit of your question!

Have you told MIOS how many Shift Regsters you have???

in your Init() function you should have at least the following:

MIOS_SRIO_NumberSet(1); // How many Shift Registers are connected
MIOS_SRIO_UpdateFrqSet(1); // How often (in mS) are SR's polled
MIOS_SRIO_DebounceSet(10); // How much debounce (in mS) is applied

If you already have this then I would check your wiring :)

Phil

[stryd_one]

Oops missed that bit sorry! Thanks philetaylor :)

Is there a troubleshooting, as for the Core ? I seem to have right voltage levels..

If your voltages look OK, and your app is correctly configured (which app is it anyway?) SRIO interconnection test and ain64_din128_dout128 applications will narrow it down... Remember to test the SRIO control lines on all points all the way from pic to 165. The problem may not be the 165 or the protoboard,,

If you don't have some other form of input (pots etc), it's probably worth using MIOS Studio to print a message on screen and see if the core is alive.

[demym]

Thaks Phil, no, i didn't have those instructions in Init....

Now i've added them, but still no response.... I've noticed that i have 1.76V on datalines not used.... (i didn't wire them at all)..

Also (found this accidentally), if i short to ground pin 9 of IC (HQ - SI of J9), i get response to DIN_NotifyToggle (MIOS Studio prints out the midi messages i send on DIN activity....)

I'm pretty sure the wiring is correct (apart from not connecting the datalines not used, i only have one button by this time)..

I also tried to upload MIDIBOX128 software to the Core, but got the same no response from the protoDIN...

What is SRIO interconnection test ?

Thx guys