Post Created date
How do you make a frequency divider from transistors
You are right Jim.  That flip-flop wouldn't work.  I think you are right it is just easier to get the right crystal.  They're cheap and easy.
Tue. Jan 15, 2019 - 11:27 PM
How do you make a frequency divider from transistors
My mistake Brian.  I thought your schematic was for a flip-flop, not the whole frequency divider.
Tue. Jan 15, 2019 - 07:36 PM
How do you make a frequency divider from transistors
You can make a flip-flop with two transistors.  I think Brian is way complicated.  I actually made a couple of these and they worked fine.  If your transistors are...
Tue. Jan 15, 2019 - 06:17 PM
new AVR programmer
I recently bought a Chinese AVRISP mkII for $20 when my old one suddenly decided to go on vacation.  It looks just the original Atmel product and at half the price I paid...
Sun. Dec 23, 2018 - 06:11 PM
Numeric Format Conversions?
ka7ehk wrote:Thanks for the hint about K&R. Have 2nd Edition PDF. I have a first edition with a red stamp on the inside cover that says, "PROPERTY OF U.S. GOVERNMENT."  I...
Sat. Dec 22, 2018 - 12:50 AM
Why doesn't external RESET pin work (to restart the program)?
Attached is an Atmel App Note that has some good stuff.  Section 3 is about the reset pin.  I usually dont use the cap or diode and just use a 10K pullup resistor and...
Fri. Dec 21, 2018 - 06:46 PM
Numeric Format Conversions?
I had an issue reading 4 bytes from a detector that was a floating point number.  When I pushed the 4 bytes into a float I got garbage.  What I had to do was push ...
Fri. Dec 21, 2018 - 06:34 PM
Different pull-ups for TWI level shifter
dviktor wrote:Are there any rules of thumb how to get (approximate) bus capacitance? Not sure myself.  Can I just put a capacitance meter on the SDA and SCL pins of the...
Mon. Dec 17, 2018 - 11:23 PM
Different pull-ups for TWI level shifter
Attached is what Ti has to say about pullup resistors.
Mon. Dec 17, 2018 - 06:19 PM
External Interrupt
Gee, I had to look in K&R to find that goto is really available in C.  I thought they did away with it after FORTRAN.  Now I am going to have to find a way to use it.
Sat. Dec 15, 2018 - 06:28 PM
SPI communcation without SS
On the AVR side you can set SS as output and use it as a GPIO.  SPI will work fine that way.
Thu. Dec 13, 2018 - 05:35 PM
mobile phone to AVR
John, thanks for putting up with me yesterday.  I think I got a little pushy.  I really appreciate the info you gave me.  It got me started, even if we are now "old...
Wed. Dec 12, 2018 - 05:53 PM