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allenhuffman
Joined: 17 Jun 2019
Posts: 552
Location: Des Moines, Iowa, USA
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| [Solved: HW] 24FJ256GA106 - puzzled by output_xxx and pins |
 Posted: Fri Feb 12, 2021 9:16 am |
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EDIT: It was a hardware issue. Nothing to see here, move along...
I am bringing up a new board based on a 24FJ256GA106. It has two LEDs hooked to I/O pins, and my first test was to create something with the PIC24 wizard that blinks the LEDs fine:
| Code: |
output_high (PIN_B10); // LED 1 ON
output_low (PIN_B11); // LED 2 OFF
delay_ms (500);
output_low (PIN_B10); // LED 1 OFF
output_high (PIN_B11); // LED 2 ON
delay_ms (500);
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But once I started trying to turn the LEDs on manually, I found odd behavior. It wasn't letting me set them both on manually. Even just trying to set them both to high would only turn on one. I've tried output_high() and also output_bit (which is what our existing code uses on the other board).
On the old project, this works fine:
| Code: |
#define LED_FAULT PIN_B6 // LED4 enable - Fault
#define LED_RF_ON PIN_B8 // LED5 enable - RF ON
#define LED_READY PIN_B11 // LED1 enable - READY
...
void LED_ReadyOn (void)
{
output_bit (LED_READY, ONE);
}
void LED_ReadyOff (void)
{
output_bit (LED_READY, ZERO);
}
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But the same code on the new board behaves differently. I can't even do this in startup:
| Code: |
#define LED_COM PIN_B10
#define LED_FAULT PIN_B11
output_bit (LED_COM, 1);
output_bit (LED_FAULT, 1);
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Before I take this back to the hardware folks, I wanted to post here in case there was something magic I don't know. I am able to control all three LEDs as expected on the older board, but on this new one I cannot.
I spot checked our four other board projects as well, and they do it the same and also work.
Anything obvious I am missing?
UPDATE: One difference in the design is that the I/O pins I am using go through a 74HC05D on the new board. From the data sheet, that shouldn't be affecting other pins, but I need to look more in to this since it's a definite difference.
_________________
Allen C. Huffman, Sub-Etha Software (est. 1990) http://www.subethasoftware.com
Embedded C, Arduino, MSP430, ESP8266/32, BASIC Stamp and PIC24 programmer.
http://www.whywouldyouwanttodothat.com ?
Last edited by allenhuffman on Fri Feb 12, 2021 9:53 am; edited 1 time in total |
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temtronic
Joined: 01 Jul 2010
Posts: 9221
Location: Greensville,Ontario
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| Posted: Fri Feb 12, 2021 9:44 am |
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hmm... random thoughts...
what kind of 'i/o' did you specify ?
standard or fast ?
are the TRIS settings correct ?
any pullups on the PIC/74HC05 ?
is the PIC a 5 volt device ? |
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allenhuffman
Joined: 17 Jun 2019
Posts: 552
Location: Des Moines, Iowa, USA
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| Posted: Fri Feb 12, 2021 9:51 am |
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| temtronic wrote: | hmm... random thoughts...
what kind of 'i/o' did you specify ?
standard or fast ?
are the TRIS settings correct ?
any pullups on the PIC/74HC05 ?
is the PIC a 5 volt device ? |
I'm not sure on any of this yet. I just got the board yesterday and have been going through the schematics to identify all the parts I will be supporting on it. They based the design on our previous 24FJ256GA106, though, but it didn't have this chip between the PIC and the LEDs.
It's looking like a hardware thing. I can blink lights on the other board just fine.
I did try enabling I/O in the PIC24 wizard, which generated this line:
| Code: | | #use FIXED_IO( B_outputs=PIN_B11,PIN_B10 ) |
But that had no impact. I've passed this back to the hardware designer to see if there's a short or something in the hardware.
| Code: |
while (TRUE)
{
DEBUG_PRINTF ("0");
output_bit (PIN_B10, 0); // works (both off)
output_bit (PIN_B11, 0);
delay_ms (1000);
DEBUG_PRINTF ("1");
output_bit (PIN_B10, 0); // works as expected (B10 off, B11 on)
output_bit (PIN_B11, 1);
delay_ms (1000);
DEBUG_PRINTF ("2");
output_bit (PIN_B10, 1); // works as expected (B10 on, B11 off)
output_bit (PIN_B11, 0);
delay_ms (1000);
DEBUG_PRINTF ("3");
output_bit (PIN_B10, 1); // bad - both off
output_bit (PIN_B11, 1);
delay_ms (1000);
}
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_________________
Allen C. Huffman, Sub-Etha Software (est. 1990) http://www.subethasoftware.com
Embedded C, Arduino, MSP430, ESP8266/32, BASIC Stamp and PIC24 programmer.
http://www.whywouldyouwanttodothat.com ? |
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allenhuffman
Joined: 17 Jun 2019
Posts: 552
Location: Des Moines, Iowa, USA
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| Posted: Fri Feb 12, 2021 9:52 am |
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Whelp, mystery solved. They found a board issue with a pin not being properly grounded.  I'm not going mad after all.
_________________
Allen C. Huffman, Sub-Etha Software (est. 1990) http://www.subethasoftware.com
Embedded C, Arduino, MSP430, ESP8266/32, BASIC Stamp and PIC24 programmer.
http://www.whywouldyouwanttodothat.com ? |
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Ttelmah
Joined: 11 Mar 2010
Posts: 19499
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| Posted: Fri Feb 12, 2021 10:35 am |
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Well done finding it.
This at heart is 'why' we so often scream to check the hardware!. Especially
as you get to larger chips, being confident that everything really is
connected as you think it is, can get very hard...  |
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allenhuffman
Joined: 17 Jun 2019
Posts: 552
Location: Des Moines, Iowa, USA
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| Posted: Fri Feb 12, 2021 11:05 am |
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| Ttelmah wrote: | Well done finding it.
This at heart is 'why' we so often scream to check the hardware!. Especially
as you get to larger chips, being confident that everything really is
connected as you think it is, can get very hard... |
I was really hoping it was a "oh you aren’t doing pin select properly, it should never have worked on your old board" or something ;) I’d rather be dumb and learn something than have to wait for a hardware fix, heh.
_________________
Allen C. Huffman, Sub-Etha Software (est. 1990) http://www.subethasoftware.com
Embedded C, Arduino, MSP430, ESP8266/32, BASIC Stamp and PIC24 programmer.
http://www.whywouldyouwanttodothat.com ? |
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temtronic
Joined: 01 Jul 2010
Posts: 9221
Location: Greensville,Ontario
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| Posted: Sat Feb 13, 2021 6:15 am |
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re: | Quote: | | Whelp, mystery solved. They found a board issue with a pin not being properly grounded. |
Reminds me of a 'mystery module' in one of my remote energy control systems. It worked great Fall, Winter, Summer...then randomly would 'fail to communicate. So swapped it out, set on bench..it worked fine...sigh. Eventually it 'died'. After 2-3 hours located the problem. The 'wiper' of the 5K pot (24Hz clock) hadn't been soldered, so simply a light 'press fit' connection. In the right heat-humidty, the pin went open circuit, clock stopped, board 'died'. Spent the next week design/build a 24Hz clock plugin 'daughter' board with xtal/caps and three 4000 series CMOS chips. After that no problems running modules 15 miles away on copper wires. |
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