Search found 8 matches
- Fri Nov 10, 2017 5:07 pm
- Forum: General discussion
- Topic: Stretch: will not dhcp ip
- Replies: 1
- Views: 568
Stretch: will not dhcp ip
Hello, Seem to have a very odd issue with stretch, both lite and desktop. Both fail to get an IP via dhcp! If I put jessie up on the same hardware, no problem, gets IP just Fine. What is interesting the request is getting to the dhcp server and giving a 'binding state abandoned' Background: I have a...
- Mon Feb 08, 2016 3:25 pm
- Forum: General discussion
- Topic: GPIO Buffer circuit pull down
- Replies: 10
- Views: 1776
Re: GPIO Buffer circuit pull down
Thanks for that.. I'll pop the scope back on and see what voltage is being presented to the input of the SN7407 The calculations above are to the maximum guaranteed values across temperature and individual device variance. You may see something else in your lab setup, but it's usually best to desig...
- Mon Feb 08, 2016 2:35 pm
- Forum: General discussion
- Topic: GPIO Buffer circuit pull down
- Replies: 10
- Views: 1776
Re: GPIO Buffer circuit pull down
Only pins 11,12,13, and GND connected, be it tat 11,12,13 are connected to the inputs of the SN7407. I have checked for shorts between adjacent pins of the chip. I will try again, by removing the SN7407.joan wrote:This is with nothing connected to the GPIO you are measuring apart from a scope?
John
- Mon Feb 08, 2016 2:31 pm
- Forum: General discussion
- Topic: GPIO Buffer circuit pull down
- Replies: 10
- Views: 1776
Re: GPIO Buffer circuit pull down
Your approach is reasonable. If I'm reading the SN7407 data sheet correctly, the maximum input low current is 1.6 mA and the maximum input low voltage is 0.8 V. This would suggest your input pull down resistor should be less than (0.8 V / 1.6 mA) or 500 ohms to guarantee a valid logic low input. Th...
- Mon Feb 08, 2016 2:27 pm
- Forum: General discussion
- Topic: GPIO Buffer circuit pull down
- Replies: 10
- Views: 1776
Re: GPIO Buffer circuit pull down
1k seems a bit low. You'll be wasting quite a bit of current. 4k7 or higher would be better. GPIO 0-8 default high, the rest on the expansion header default low. Hello 0-8 high.. odd I'm using pins 11,12,13 (GPIO17, GPIO18, GPIO27) on rev 2, so these should be low, which they are not, checked on a ...
- Mon Feb 08, 2016 1:36 pm
- Forum: General discussion
- Topic: GPIO Buffer circuit pull down
- Replies: 10
- Views: 1776
GPIO Buffer circuit pull down
Hello, I have been working on a circuit which uses 3 outputs via a buffer chip (SN7407) and have noticed an interesting problem. I have solved it, but wonder if this is the ideal solution. It seems when the Pi is powered up or powered down the GPIO pins (well most) of them go high impedence inputs, ...
- Sun Dec 29, 2013 2:47 pm
- Forum: Automation, sensing and robotics
- Topic: Driving multiple servos from the RaspberryPi
- Replies: 212
- Views: 120846
Re: Driving multiple servos from the RaspberryPi
Hello,
I looked like I needed to update the kernel source .config file with a valid one, the driver now compiles.
Just need to test it....
John
I looked like I needed to update the kernel source .config file with a valid one, the driver now compiles.
Just need to test it....
John
- Sun Dec 29, 2013 12:26 pm
- Forum: Automation, sensing and robotics
- Topic: Driving multiple servos from the RaspberryPi
- Replies: 212
- Views: 120846
Re: Driving multiple servos from the RaspberryPi
Hello, I'm trying to compile the driver, however I'm, getting the following error /home/servoblaster/PiBits/ServoBlaster/kernel/servoblaster.c:52:27: fatal error: mach/platform.h: No such file or directory I have the latests kernel source downloaded and compiled. (3.10.25) I suspect the include path...