I have a Raspbery pi3 with domoticz and Node-red installed. both are using GPIO with sysfs. When changing an output to high in either domoticz or node-red the value in the file is set to 1.
(/sys/class/gpio/gpio/value)
When setting an output high in node-red, domiticz does not reflect the pinstate in the device.
When setting an output high in domoticz, node-red does not reflect the pin state in the flow.
Am i missing something here or is this the way it suppose to work?
i understood from the documentation that the use of the files was to make the GPIO more general usable by setting the values in there.
Related
I am making a CAN simulator for GPS trackers, they only record CAN data and doesn't send ACK. Is it possible to send CAN data with raspberry, using mcp2515/tja1050, without any device on bus that would trigger ACK?
This will usually generate a continuous retransmit.
Some devices have a "one-shot" transmit mode when just sends the CAN frame and does not attempt a retransmission. If you transmitter has this mode you can do what you describe, otherwise you will get a lot of retransmissions.
No it isn't possible, you need at least 2 nodes that are actively participating in the communication. This can however be fixed by just providing another CAN controller on the bus, which doesn't have to do anything intelligent except the ACK part.
For development/debug/test purposes you can however put your own node in "loopback mode", meaning it will speak to itself. Can be handy if you have to proper hardware available yet.
You can try to set the controlmode presume-ack to on.
Assuming you are using the ip command for creating your can sockets that would be something like
ip link set <DEVICE> type can presume-ack on
This will ignore missing ACKs. However I am not sure whether this works with all controllers.
I am working with openmote-cc2538 for the project: https://github.com/cetic/6lbr/wiki
Here when I was trying to flash openmote with this command
sudo make TARGET=cc2538dk BOARD=openmote-CC2538 bootload0/dev/ttyUSB0 slip-radio.upload
This error message is displayed
ERROR:Cant CONNECT TO TARGET:Ensure bootloader is started(no answer on sync sequence)
cc2538 bsl.py script is available for uploading binary to openmote. But I don't have much experience about this. Can anybody give me some suggestions regarding how to proceed??
Grab a scope and probe different digital I/O pins on the CC2538. Typically a bootloader will initialize all the ports on the chip and you will see them change state, which is an indication that the bootloader is indeed running. I would guess one of the LEDs would change state as well (which doesn't require a scope).
I am trying to create 2 virtual serial ports in my windows7-64 bit machine to run my applications which communicate over serial ports.
I have tried these software:-
FreeVirtualSerialPort, KerProAdvancedVirtualComPort, VirtualSerialPortDriver, VirtualSerialPortEmulator, VirtualSerialPortKit and com0com
The communication works fine, however I am unable to receive parity bit with the data. Just want to know if someone has used any of these or other software and received parity correctly. My applications use Mark and Space parity. Is there a software which supports 9-bit communication.
The parity errors are detected by hardware and reported to driver. It is then upto driver and serial port configurations about how to handle this error. If the application has requested to get notified about parity error operating system specific action is taken for example setting a particular flag which app can use to determine whether error happened or not.
Very few application uses 9th bit and also hardware supporting them are also less. There is an article also about 9th bit. BTW why you need 9th bit at app level.
Im using MCP25625 which is MCP2515+integrated MCP2551 and trying to send messages in a loop.
For some reson I dont see any signal at all on CANH, CANL lines.
SPI communication works correctly
I use software reset procedure
There is clear 20Mhz sinewave from Crystal
There is TXCAN signal
At the moment there is nothing at all connected to CANL,CANH, just the probe.
I also tried to run in LOOPBACK mode and it works, but in the NORMAL modethere is nothing coming out.
Seems like transciever is broken? I changed 2 chips already, so it shouldnt be the problem.
Any suggestion guys?
Schematics
have you considered the modes of operation of the CAN transceiver?
In your schematic, the pins value is not clear.
If you have connected it to the MCU, Please pull it to LOW to select the normal operation mode for the transceiver (it is different configuration then the CAN controller settings, hence might cause some confusion!).
Controlling it by MCU is a good choice as it gives more control to prevent network communication from being blocked, due to a CAN controller which is out of control.
Else, connect it to ground to ensure normal operation mode specifically for the build in transceiver.
I have referred the data-sheet's of MCP25625, MCP2515 and TJA1050 to bring out this conclusion.
TJA1050 has pin-S for selecting high-speed mode and silent mode. Both modes are similar to normal mode and standby mode respectively of the transceiver of MCP25625.
Also, pin-S configuration in TJA1050 is similar to pin-STBY configuration in MCP25625.
0(LOW) for high-speed/normal mode of TJA1050/MCP25625-Transceiver
1(HIGH) for silent/standby mode of TJA1050/MCP25625-Transceiver
Hope this helps.
At the moment there is nothing at all connected to CANL,CANH, just the probe.
Hope you have connected the termination resistor? It is on the schematic, but ...
I am currenlty trying to monitor my battery status through SMBus.
I have a battery along with a control board that constantly outputs the battery status.
This control board is then connected to my mother board through a I2C-USB module.
I need to write a program to recognize the SMBus connection and transmit the battery status to the user.
I'm a beginner when it comes to dealing with smart batteries and I2C/SMBus, and I'm somewhat lost with how to approach this problem.
Any help of suggestions would be appreciated. Thanks.
Your question is a bit lacking. What kind of I2C-USB module? Or rather does it come with a Linux driver? If it does you probably won't need to write one. An application will do. You can read more about I2C and SMBus here.
Basically what you need is the I2C address of the control board (a single byte). When you have the address you (as the master) issue read commands over the I2C bus to the control board using its address and reads the response. If there's a driver for the I2C-USB module this should be straightforward enough. Plug in the device and open() the device (/dev/[i2c-usb-name] where [i2c-usb-name] is the name of the device). Then follow the driver implementer's guide how to setup and send data over that device (typically using read()/write() or ioctl()). Here are some additional information on working with I2C from user space: http://www.mjmwired.net/kernel/Documentation/i2c (select topics in the menu on the left hand side).
If you must write the driver yourself, the first stop for a Linux device driver beginner is the LDD3. Read it, it's quite a pleasant read.