Is it possible for an I2C master device to communicate with another I2C master device ?
Thanks
Yes! As long as it specifies that it can do Multi Master operation, then it can communicate with another Master device. There is a clock synchronization procedure that two masters need to perform. To see how that works, read this PDF, section 4.3.1
I2C FPGA Core from Opencores
Yes it's possible..
But clock synchronization is important part.
Hope u go through above given PDF.
Related
I make this post because I didn't find the answer (I made some searches with tag Shutdown, Reboot and SSH).
Since fews months, I've got 2 Corals (out of 3) that shutdown unexplicaly and then become unreachable.
When this occur, I'm forced to go the device (the serial connectivity doesn't work either and the fan doesn't works at this time), unplug and then re-plug the power in order to be able to reconnect through SSH.
What the best thing to do ?
Thanks a lot.
I've seen similar behavior with low power. Be sure you are connecting your board to a 2-3 A power supply. A couple indications that this might be your problem are:
Your board is connected to your computer USB power
Your board runs fine until you load it (i.e. start inferencing on the TPU)
That's the first things I would look for.
dsPIC33EP syncronisation
Hello,
Can someone explain how can I synchronize multiple slaves in an I2C network using dsPIC33EP256GP502 and the details are attached in the link above.
Thanks and Regards,
Akhil
I am using redis version 2.8.3. I want to build a redis cluster. But in this cluster there should be multiple master. This means I need multiple nodes that has write access and applying ability to all other nodes.
I could build a cluster with a master and multiple slaves. I just configured slaves redis.conf files and added that ;
slaveof myMasterIp myMasterPort
Thats all. Than I try to write something into db via master. It is replicated to all slaves and I really like it.
But when I try to write via a slave, it told me that slaves have no right to write. After that I just set read-only status of slave in redis.conf file to false. Hence, I could write something into db.
But I realize that, it is not replicated to my master replication so it is not replicated to all other slave neigther.
This means I could'not build an active-active cluster.
I tried to find something whether redis has active-active cluster capability. But I could not find exact answer about it.
Is it available to build active-active cluster with redis?
If it is, How can I do it ?
Thank you!
Redis v2.8.3 does not support multi-master setups. The real question, however, is why do you want to set one up? Put differently, what challenge/problem are you trying to solve?
It looks like the challenge you're trying to solve is how to reduce the network load (more on that below) by eliminating over-the-net reads. Since Redis isn't multi-master (yet), the only way to do it is by setting up each app server with a master and a slave (to the other master) - i.e. grand total of 4 Redis instances (and twice the RAM).
The simple scenario is when each app updates only a mutually-exclusive subset of the database's keys. In that scenario this kind of setup may actually be beneficial (at least in the short term). If, however, both apps can touch all keys or if even just one key is "shared" for writes between the apps, then you'll need to bake locking/conflict resolution/etc... logic into your apps to consolidate local master and slave differences (and that may be a bit of an overkill). In either case, however, you'll end up with too many (i.e. more than 1) Redises, which means more admin effort at the very least.
Also note that by colocating app and database on the same server you're setting yourself for near-certain scalability failure. What will happen when you need more compute resources for your apps or Redis? How will you add yet another app server to the mix?
Which brings me back to the actual problem you are trying to solve - network load. Why exactly is that an issue? Are your apps so throughput-heavy or is the network so thin that you are willing to go to such lengths? Or maybe latency is the issue that you want to resolve? Be the case as it may be, I recommended that you consider a time-proven design instead, namely separating Redis from the apps and putting it on its own resources. True, network will hit you in the face and you'll have to work around/with it (which is what everybody else does). On the other hand, you'll have more flexibility and control over your much simpler setup and that, in my book, is a huge gain.
Redis Enterprise has had this feature for quite a while, but if you are looking for an open source solution KeyDB is a fork with Active Active support (called Active Replica).
Setting it up is just a little more work than standard replication:
Both servers must have "active-replica yes" in their respective configuration files
On server B execute the command "replicaof [A address] [A port]"
Server B will drop its database and load server A's dataset
On server A execute the command "replicaof [B address] [B port]"
Server A will drop its database and load server B's dataset (including the data it just transferred in the prior step)
Both servers will now propagate writes to each other. You can test this by writing to a key on Server A and ensuring it is visible on B and vice versa.
https://github.com/JohnSully/KeyDB/wiki/KeyDB-(Redis-Fork):-Active-Replica-Support
I have programmed a couple of MSP430x6xx microcontrollers to serve as Master for some I2C slave devices. One of the MSP430s transfer the data received from I2C slaves to a PC using its built in USB Module. I want to extend this to allow all Micro controllers to send data received from their respective I2C slaves to PC using a common bus system. Will it be feasible to use SPI for transferring the data from all MSP430s to a single MSP430 master(already serving as I2C master and USB device simultaneously) which then transfers it to PC? I would appreciate any other suggestions. Thanks
Yes, it is feasible we will have to write your firmware to handle this. You have to identify on the PC somehow from whom SPI/I2C slave it comes the data. So, your main MSP430xxx will do this adding some kind of header to the data saying the id of the slave device.
I have some questions regarding communication over USB cable in Linux, in a Host-Target Device environment.(USB2.0) Please help as we are stuck for the below imiplementation.
We have a host PC connected to a target device (Linux OS) through USB cable.
On the target device we need to spawn 3 or 4 child processes. [Using fork() or some equivalent system call]
All the child process should communicate to the host PC independently though there own source file descriptor and sink file descriptors.
As per our experimentation, one process communicates to the PC at a time then the control is given to another process. But our requirement is for simultaneous communication. We are not sure whether USB driver(2.0/3.0) supports this methodology.
Any pointers regarding this will be helpful.
Thank you.
-AD
As per our experimentation, one process communicates to the PC at a time then the control is given to another process.
This is how computers work. Only one thread at a time has control of a particular CPU - when it blocks for i/o or exhausts its quantum, control is given to another thread.
What do you need simultaneity for that you can't manage with sending data one after the other?
USB is a serial bus protocol with a SINGLE DATA BUS, and this means, what you are looking for is not possible.
But we can have 4 different USB COMMUNICATION PIPES which can provide different paths, but NOT simultaneously.