MiniPOV3 to USBtinyISP adapter cable?

MiniPOV4 and previous versions

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bsbowens
 
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MiniPOV3 to USBtinyISP adapter cable?

Post by bsbowens »

We have two MiniPOV3's that we're trying to program with a bunch of Macs and an Ubuntu laptop, and not a true serial port in the bunch. I borrowed two Keyspan USA-19QW USB-serial adapters from work, but neither one will program the kits, on Mac or Linux. Happily, I also have a USBtinyISP, and with some jumpers and a solderless breadboard was able to program both MCUs and get them spelling out cool things.

However, rather than prying the chips out of the kits each time we want to change something, I was hoping that I could make a simple adapter from a piece of double-row header, a DB-9M and some short jumpers. I soldered it up, connecting five of the six pins on the header - Vcc isn't brought out to the DB-9F on the MiniPOV. And. . . it doesn't work. I'm using the same host (the Ubuntu laptop) that can program just fine with the breadboard lashup, but it does not see the MCU.

I thought that perhaps the 4.7k resistors were a problem, so I jumpered across each one with clipleads. No change. I haven't tried disconnecting the zeners, though I don't see why they would be a problem. I've checked the adapter backwards and forwards, including walking the pins with an ohmmeter. I've also checked the DB-9F on each board, following the pins back to the resistors or the nearest via.

If this *should* work, I'll assume that I've done something wrong either with the kits or with the little adapter. If it shouldn't work this way, is there something I can change on the kits to make it happen?

Thanks,
Bill.

mtbf0
 
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Re: MiniPOV3 to USBtinyISP adapter cable?

Post by mtbf0 »

bsbowens wrote:Vcc isn't brought out to the DB-9F on the MiniPOV.
but you are powering the board while attempting to program it, right?

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opossum
 
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Re: MiniPOV3 to USBtinyISP adapter cable?

Post by opossum »

Try removing R1, R2, R3

http://forums.adafruit.com/viewtopic.php?f=11&t=5013


Firmware that uses the serial port in a conventional way...

http://forums.adafruit.com/viewtopic.php?f=11&t=4941

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bsbowens
 
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Re: MiniPOV3 to USBtinyISP adapter cable?

Post by bsbowens »

oPossum wrote:Try removing R1, R2, R3

http://forums.adafruit.com/viewtopic.php?f=11&t=5013
Aha. Now, why didn't that post come up when I searched this forum? Oh well. . .

The upshot, then, is that an unmodified MiniPOV3 can't be programmed with an ISP cable. At least I can stop banging my head against the table while trying ;)
oPossum wrote:Firmware that uses the serial port in a conventional way...

http://forums.adafruit.com/viewtopic.php?f=11&t=4941
Now, that looks promising! I'll give it a try. . .

Thanks for the help,
Bill.

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