Element14 has no shortage of 14 to 20 pin 8-bit MCUs in DIP
Atmel and Microchip do 14 pjn parts, but not 16 for 16 pin parts you'll be using a Freescale or ST-Micro core. at 18 pins it's a PIC or a Z8
20 pins has many options. (all the above)-- umop apisdn --- news://freenews.netfront.net/ - complaints: news@netfront.net ---
Lemme see,,2 pins for power, one pin for I/O serial. Cleans the kitchen sink, replaces Win8.5, generates power for your Lexis, and runs on a 1.5V AAA cell; in a SOT23-3. Make the EU tell you _which_ pin to remove...
It leaves 8 pins free for I/O which I think is what you said you needed, no? It's even the same size as a 16 pin DIP.
-- Rick
On a sunny day (Sat, 30 Aug 2014 13:41:01 -0700 (PDT)) it happened snipped-for-privacy@gmail.com wrote in :
OK, I have done this simpler. remember the rule: I (me myself) only need ONE free pin to find out all about a micro.
So lets play it that way. PIC 1: a 8 pin PIC:
2 power 2 RS232 1 I/O for communicationNow you have 3 fast I/O left on PIC 1
PIC 2: a 8 pin PIC
2 power 1 I/O for commnuncationNow you have 5 I/O left on PIC 2
Together you now have 8 I/O available
Dunno if that is enough.
How does inter-PIC communication work? Let's use simple RS232
Normally both PIC pins are configured as input.
When PIC 1 wants to set an I/O pin in PIC 2, then it reconfigures the port as output, and sends: X so only 2 bytes, the character X being the command: "output config follows".
When PIC 1 wants to know the state of the pins of PIC 2, then it sends the command: Y and then imediately as always goes back to input and listening. PIC 2 will then send one byte, the status of its PINS, or however many bytes (could be some analog value too). I have used something like this is at least 2 (probably more projects). RS232 is really cool, by using bit 9 you can do it multiple procesor multiple PICs too.
An other way to reduce I/O (cabling) is put a simple PIC elsewhere to make 4 bit wide LCD displays etc RS232 capable. The possibilities are endless.
If you are BRAVE, take some 18 pin processor that does not have its power pins on the edge, (or use other edge) and cut of the last 2 pins, now its 16 pins, I have done that too. If a hole is left in the package fill it with 10 second glue or something else.
LOL
Well its early on Sunday, so ... :-)
I me myself wrote
What I have also done is use a PCF8574 I/O expander soldered on the back of the 2 line character LCD. If your micro already _has_ I2C in use for other chips, then driving a character LCD takes no extra pins whatsoever. I have some BASIC (!) example code and can draw up the circuit diagram (if I can find it) if anybody is interested. That code is from before cellphones and internet... When MCS BASIC on a 8052 micro... When was that? late eighties, early nineties?
I still have that computah! mm can probably list the code :-)
How far away can you drive the PCF8574? If I don't put the micro in this I/O board, i can put the micro around 2 feet away and drive it with serial or I2C.
SPI, maybe, depending on speed and what you use to drive the lines. OTOH, you'll never get away with driving I2C anywhere close to that far without some sort of network to bridge over. I2C is limited to
400pF and is very sensitive to the waveforms. There are games that can be played to up that a little but 2' is going to be *really* tough.
s I/O board, i can put the micro around 2 feet away and drive it with seria l or I2C.
have you tried? 400pf is ~25' of cat5 cable
you video card get info about your monitor via I2C, your monitor cable is p robably longer than 2'
-Lasse
On a sunny day (Sun, 31 Aug 2014 09:56:54 -0700 (PDT)) it happened snipped-for-privacy@gmail.com wrote in :
20 meters I have used, with the LCD as name shield in the front door. That was I2C via normal 4 core shielded audio wire (the flexible stuff). just reduce the speed a bit.I have used I2C to connect devices (large LCD displays) in office buildings,
50 or so on a cable, but with a special driver circuit (+- 12V 100 Ohm IIRC). This last thing is easy one way if you do not need the ack bit.I have boxes with say 1 or 2 meters cable (normal speed 100 kHz or so) I2C in use for all sorts of things, some driven from the PC par port, like subtitle stuff etc. its looking at me now, that one uses just stereo audio cable.
Its a cool interface.
On a sunny day (Sun, 31 Aug 2014 13:10:52 -0400) it happened snipped-for-privacy@attt.bizz wrote in :
You are wrong.
s I/O board, i can put the micro around 2 feet away and drive it with seria l or I2C.
you'll never get away with driving I2C anywhere close to that far without some sort of network to bridge over. I2C is limited to 400pF and is very s ensitive to the waveforms. There are games that can be played to up that a little but 2' is going to be *really* tough.
Alternatively, an HC595 with Max232 drivers.
I have boxes with say 1 or 2 meters cable (normal speed 100 kHz or so) I2C in use for all sorts of things, some driven from the PC par port, like subtitle stuff etc. its looking at me now, that one uses just stereo audio cable.
Its a cool interface.
PS
On a sunny day (Sun, 31 Aug 2014 10:36:32 -0700 (PDT)) it happened snipped-for-privacy@gmail.com wrote in :
No need for any of that.
I've not tried 2', no. I have tried interboard connectors and failed, without something like the LT I2C accelerator.
this I/O board, i can put the micro around 2 feet away and drive it with se rial or I2C.
OH, you'll never get away with driving I2C anywhere close to that far witho ut some sort of network to bridge over. I2C is limited to 400pF and is ver y sensitive to the waveforms. There are games that can be played to up tha t a little but 2' is going to be *really* tough.
It will be very noisy, next to a 72V motor. At least some kind of high vol tage line drivers.
On a sunny day (Sun, 31 Aug 2014 11:09:42 -0700 (PDT)) it happened snipped-for-privacy@gmail.com wrote in :
well, eh, I have used it with 100 W PEP at 27 MHz next to it, enough to crash a VHS.... Did not notice a thing. Screened cable. The cable capacitance shorts any RF. This box (from the picture) has seen at least 15 years error free operation, apart from those horrible RCA video connectors :-) Watch your ground loops.
Preferably with >5M gates, an ARM core, internal config EEPROM, RAM, an internal calibrated TCXO, and a PCIe 3.0 capable SERDES on each pair of adjacent pins :)
Dimitrij
PIC, but they are too long. I just need 2 pins for RX/TX and 6 I/Os. 16 pins DIP would be ideal.
I wouldn't have space for DIPs anyway. I don't remember the last time I used a DIP. It's gotta be close to 20 years, and they were leftovers from a decade before that.
can prototype/build their own PCB. There are 8 pins and 28 pins DIP AVR and 28 pins PIC, but nothing in between, unfortunately.
Maybe you should look harder. I can find 14, 16, and 20 pin dip PICs. I'll bet that there are similar AVRs.
?-)
I should have said nothing decent under 28 pins (not even 8 pins). I need at least ATmega, PIC24, or ARM.
snipped-for-privacy@gmail.com wrote in news: snipped-for-privacy@googlegroups.com:
16 bit bus PICs with a UART =========================== 14 pin: PIC24F04KA200, PIC24F04KL100, PIC24F08KL20018 pin: dsPIC30F2011, dsPIC30F3012, dsPIC33FJ06GS001 dsPIC33FJ06GS101A, dsPIC33FJ06GS101
20 pin: dsPIC33FJ12GP201, dsPIC33FJ12MC201, dsPIC33FJ16GP101 dsPIC33FJ16MC101, dsPIC33FJ32GP101, dsPIC33FJ32MC101 PIC24F04KA201, PIC24F08KA101, PIC24F16KA101 PIC24F04KL101, PIC24F08KL201, PIC24F08KL301 PIC24F08KL401, PIC24F16KL401, PIC24F08KM101 PIC24F16KA301, PIC24F32KA301, PIC24FJ16MC101 PIC24FJ32MC101, PIC24HJ12GP201Of course, it all depends on your definition of "decent"
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