Oracles Forum about JavaME is dead! I'm sorry to say, but questions never get an answer.
The javaME-GettingstartedGuide.pdf from Oracle tells me: The GPIO pins are preconfigured! Does this mean I must take it as it is and JavaME does not allow any configuration? Further, the document tells me Device ID 1, named GPIO4 is input only and mapped to pin 4! But the Pi documentation tells me Pin 4 is connected to +5V! Where can I find valid information?
The problem relies in the two kind of numbering. A Raspberry style (Broadcom pin number) and raspberry physical style! You can find both in the JavaME-GettingStartedGuid, but not side by side. A problem in a GettingStartedGuid. Not being prepared you get confused! See Raspberry Pi Pinout
The question w.r.t. Pin reconfiguration in JavaME however ist still open.
Related
I just installed the latest version of LIRC(0.10.1-5.2) on my Raspberry Pi 3, running Raspbian on Debian Buster.
I am trying to get my Pi to take input from an IR remote using lirc.
I have made the necessary changes to these files :
/etc/lirc/lirc_options.conf
driver = default
device = /dev/lirc0
/boot/config.txt
dtoverlay=gpio-ir,gpio_in_pin=18,gpio_out_pin=17,gpio_in_pull=up
//I set mine on up on GPIO pins 17 and 18 instead of 22 and 23
I have checked and cross-checked my circuit. Everything looks okay.
The challenge I'm facing right now is when I test my IR receiver using the following command,
mode2 -d /dev/lirc0
Nothing happens. There's no output at all. No pulses recorded.
Has anyone else experienced this issue?
Any help would be much appreciated.
After spending a great amount of time, trying to figure out how to solve this issue, I was finally able to resolve it.
So hopefully my answer will help someone else.
First things first, it's important to note that infrared device has changed from lirc-rpi to gpio-ir
Although, I already had this change in my /boot/config.txt
file,like below:
dtoverlay=gpio-ir,gpio_in_pin=18,gpio_out_pin=17,gpio_in_pull=up
// in stead of dtoverlay=lirc-rpi
I just thought it was important to point out.
Since I am trying to get my Pi to take input from an IR remote using lirc, I decided to first test my IR sensor separately, to make sure it works.
To do that, I connected up the sensor like so:
Pin 1 is the output so we wire this to a visible LED and resistor
Pin 2 is ground
Pin 3 is VCC, connect to 3v3
You can find more detailed step by step instructions from this tutorial here which also shows how to wire up your circuit as seen below.
During this test, my LED lit up each time I pointed a remote at the receiver, which gave me hope that it was working just fine.
The next step was to test the IR receiver on my raspberry pi, which is the challenge I had in the beginning.
I re-wired my circuit, this time:
Pin 1 is DATA, goes to RPi pin 12 (GPIO 18)
Pin 2 is GND, goes to RPI pin 6 (GROUND)
Pin 3 is POWER, goes RPi pin 1 (3v3)
Then I ran this command sudo /etc/init.d/lirc stop to make sure that service wasn't running.
I then ran the initial command mode2 -d /dev/lirc0 and now pressed random buttons from my remote at the receiver and violá! I could see some pulses on the screen with each button press now.
Like you I managed to get all the way to receiving pulses/data on the RPI 3, seem to have a problem with the output.
I have the USB strip light and my RPI with the IRC receiver, this is so I can monitor what data captured corresponds with the button pressed on the remote keypad. Works just fine.
However? If I push the ON button - I get data, if I push the ON button again I get another set of data. The two set of data dont match? , in both cases mode2 or mode2 -r.
I get the feeling I'm missing a method to decode the output, I've noticed there's a huge amount of companies and they all have distinct code sets.
Here is one thread that exactly matches what I have (24-Key IR remote).
http://woodsgood.ca/projects/2015/02/13/rgb-led-strip-controllers-ir-codes/
However I dont see the same set codes ???
Try to change the device to mode2 -d /dev/lirc1
I also faced this.
I just started with microchip world.
I'm about to buy a PicKit3 and i've seen it can outputs from 1.8V to 14V MCLR.
The pic i will use is the PIC16F1829 and it should work with MCLR # 5V.
In the datasheet it seems i would need a zener/shunt to limit the voltage.
First of all isn't there a board ready to play with?
Can i use LVP? If so using MPLab 8 IDE how do i change in LVP?
Is the pin connection the same?
Since i haven't bought it yet i would rather avoid burning a pic
Regards,
Notes at the bottom of page 345 in the PIC16F1829 data sheet (DS40001440E) recommends using a voltage limit circuit when using the ICD2 device programmer.
According to Microchip this is "not required" when using the PICkit3.
Get a few extra PIC16F1829 just in case.
You ask about boards ready to use, take a look at the Curisotiy Nano boards
https://www.microforum.cc/topic/9-microchip-xpress-evaluation-boards
These are ready to use and do not need any programmer. You can simply send a file to these devices over USB. They are also have debugging capability.
In terms of the 14V on MCLR, the device is designed to handle whatever pulse will be generated by the PICkit3, so you do not need any protection for the PIC against that. In fact limiting the voltage on that pin will prevent the device from programming so you definitely do not want to do that. If you are however using this pin to connect to other parts on your board the other parts probably will need protection.
You can most definitely use LVP, just be careful, it is possible to use LVP to disable LVP, and then the only way to get it back on is to use HVP!
Lastly in the IDE under programming options you can change the mode there (Use low voltage programming mode entry)
In the IDE i've set the voltage appropriately and everything went ok on its own.
I didn't have to enable anything fancy
I have been unable to find any documentation regarding using python to change the GPIO outputs, and was wondering whether there was any specific code i could use to change it or if there were any third party programs that allowed me to do so.
You cannot change the current of GPIO pin, that's not how it works.
If you want to know the maximum value of current for GPIO pins, this article says it's 16mA per pin, with maximum of 51mA for all pins.
I have a a Sparkfun Max 7456 breakout board that I am trying to rewrite the character table to an ASCII format. I have been following the Arduino + MAX7456 OSD thread but cannot seem to load the .mcm file to the breakout board. I have tried hyper terminal and tera term. Tera term allows me to "transfer" the mcm file but I do not get any type of confirmation in the terminal window. When I try simple sample code like "Hello World.ino" I get no response and the default character set is still displayed. Hyper terminal tells me there is a COM port conflict with the Arduino IDE. I know the steps are available in the above mentioned thread but the picture/ code resources have mostly been removed. I don't know if I'm missing something in the code or if I am not using the terminal program correctly. I have the following connections between the breakout board and the Uno and have been trying Arduino code provided at the start of the thread;
Breakout/ Uno;
CS-->D10
SDIN--> D11
SCK--> D12
SDOUT--> D13
+5V
GND
I have tried using wires that are <5cm and >=10cm and I am using NTSC. Can anybody determine what I am doing wrong or point me in the right direction please. Thanks in advance,
I figured out my issue. Using Google translate I was able to get code from;
http://f5mna.free.fr/Arduiexpert.htm
Previously, I was only making the connections listed in the code when the full list is;
D13--> SCLK
D12--> SDOUT
D11--> SDIN
D10--> CS
+5VDC must be applied to the +5V pin on the board as well as a 1k resistor in series with LOS and a 10k with RESET.
As for using tera term. First shutdown the Arduino IDE and open the connection in the terminal program. The code provided in the above link will indicate it is ready for file transfer and will prompt you with a transfer complete message.
All in all, simple solutions but I was a newcomer to a very old thread. Hope this helps anyone else having the same issues in the future.
I am trying to use the expansion header to control a couple motors and auxiliary task mechanism. For this I am using the appropriate pins as GPIO and merely attempting to send high or low signals as needed by the robot. (For instance, I might need the robot to move forward and so I'd send high signals on both sets of pins, whereas if I needed the robot to turn I'd send a high signal to one pin and a low to the other.)
However, the problem is that the pins will only stay high! I've followed the conventions for sysfs just via the terminal, and, although I'm able to set the "values", "active_lows", etc. to 0 or 1, I can't actually get the pins to send 0V. After checking the beagle.h file I used for u-boot it looks like the multiplexer mode is configured correctly. This is also reflected when I get the info from sys/class/gpio/gpio%/% and sys/kernel/debug/gpio. Furthermore I don't get any errors or indication from anywhere that there is something wrong...it just doesn't work!
What should I do? For the first time in my life I have seemingly exhausted the internet...
details:
Beagleboard xm rev c1
ubuntu 12.04
kernel 3.6.8-x4
Im pretty new to the beagle board and I have recently been trying to configure the GPIO pins on my classic beagleboard c4, which i believe should be fairly similar.
Half of my GPIO pins seemed to work fine and the other half seemed to remain high or low no matter what i did. Even though they were configured the same way as the working pins in /sys/class/gpio/
have you tried to use other gpio pins?
I ended up following http://labs.isee.biz/index.php/Mux_instructions
to configure the mux to 4 and now i can control the pins that were not working.
I basically used the command:
sudo echo 0x004 > /sys/kernel/debug/omap_mux/(mux 0 name)
where (mux 0 name) was the name of the subsystem for the mux 0 setting for the gpio pin you wish to configure
ie. for gpio 183 on beagleboard c4
sudo echo 0x004 > /sys/kernel/debug/omap_mux/i2c2_sda
Though I had to change permissions to modify these files
As I said I am pretty new to the beagleboard and ubuntu but this worked for me so I thought I would share it with you, I hope it is of some help.
Regards;
Paul;
It seems that the beagleboard expansion pins are numbered in alternating fashion, as clearly and professionally depicted here.
Thanks to everyone for your help. I now know way more than I should about GPIO on OMAP systems (and so do you). Good luck on finals/life!**
tl;dr I'm an idiot!