-------- Original Message --------
Subject: [minima] Re: Testing the digital board
From: Thomas Sarlandie <thomas@xxxxxxxxxxxxx>
Date: Wed, February 05, 2014 9:19 pm
To: "minima@xxxxxxxxxxxxx" <minima@xxxxxxxxxxxxx>
Jerry,
Once you are sure that the script is loaded and working, you can just
measure the voltage on the I2C line to make sure you are not getting
5v. If
you did not comment the right thing then the i2c pullups will be
enabled
and you will get 5volts. If you did it right, you will get just 3.3
v from
the external pull-ups.
The code will drive the lines low when it is actually sending. I
have not
checked but I assume it is only doing it when you change frequency.
Even if
it does it regularly, you will see 3.3 "most of the time".
Now the LCD not displaying anything is a bigger problem and could be a
programming problem so dont measure the i2c line just yet.
First things first, most LCD will black out the first line when you
turn
them on. So if you dont see anything, the problem might just be the
contrast pot is not set correctly. Adjust it to +5v and see if you
can get
something. Eventually remove the atmega and see if you can get
something by
just applying power to the board.
Next, I would check the connection of the 4 data lines, the enable
line,
the RS line and make sure that the R/W pin is tied to low (write).
You can also look at them with a scope and see if anything happens
there
when you apply power. If there is nothing then the chip probably has a
programming problem, or is just not starting. Check that reset is
pulled
high, that the quartz is properly connected, that both gnd pins are
tied to
ground and that you have +5 on vcc and avcc.
If you have the serial port cabled, just use one of the arduino
examples
that continuously send stuff on the serial port. Program that in the
chip
with your arduino board and drop it your motherboard to see if you get
something on the serial port (a scope would be enough to see that if
you
dont have the serial port cabled).
Just a few ideas. I am following very closely and will try powering
up my
arduino and lcd tonight. This might give me some more ideas for you!
thomas
On Wed, Feb 5, 2014 at 6:40 PM, <jerry@xxxxxxxxxxxxxxxx> wrote:
I finished building the Digital board except for soldering in the
si570.
I would like to test the radiono code and make sure I made the right
comments in the file so I don't fry the si570. I fired up the board
and
all the voltages are good: 4.92 out of the 7805 and 3.24 out of the
LM1117, but I would like to run the code and check the 570's
voltage. I
uploaded the radiono sketch to the chip using a Arduino Uno board, and
put the chip in my Digital board, and powered it up. All that happens
is the LCD backlight lights, but no characters. The contrast pot
works.
The circuit draws 24ma but no display. Do I need to do something else.
There is another code file on github, what is that for? Jerry
K5LRU
Harwood, Texas
