Re: CW Key/Keyer/paddle idea
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Well, the Nano takes 5V so that has to be floating around somewhere and most LCD's are 5V devices. (Many TFT are 3.3V.)
Jack, W8TEE
From: Rod Self <km6sn@...>
To: [email protected]
Sent: Thursday, December 21, 2017 2:39 PM
Subject: Re: [BITX20] CW Key/Keyer/paddle idea
Please be aware that those I2C adapters pull the I2C lines up to
+5. If you have 3.3v I2C devices in the system, like SI570, and
others, then the +5 I2C exceeds their specs.
See my earlier post on the subject.
Rod KM6SN
On 12/21/2017 11:18 AM, Jack Purdum via
Groups.Io wrote:
They're not too expensive and work quite well. See ebay
#201042782490
Jack, W8TEE
Probably the
LCD isn¡¯t i2c capable. There are with i2c, or
use a cheap available converter.
?
Ron ¨C PA3FAT
?
?
All:
The way Ashhar is using a single ?C I/O line to
key the ?BITX is pretty clever, but some people
are having issues with different
keys/keyers/paddles. I think the main reason he
used a voltage divider for key sensing is
because he was running out of I/O pins on the
Nano. Looking at the code, the LCD display uses
the standard LiquidCrystal library, which eats
up 6 I/O pins. I know Allard has Rel. 2.0 of the
software going, but I'm wondering if A4 and A5
could be moved and the I2C interface used for
the LCD display. That would free up enough lines
for the keyer to dedicate a dit and dah pin for
each. Quite honestly, I have not looked at
Allard's code yet (too many alligators), so I'm
just tossing this out there for discussion.
Jack, W8TEE
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