I would like to use LoRa (not LoRaWAN) to send a measurement from a LoRa device to a M5 Stack (esp32) with a LoRa module using a point-to-point connection.
Is it possible to save that measurement to a database (using WiFi) after it is received by the M5 Stack? Will I be able to access the content of the received packet by the M5 Stack?
Also, if this is possible, how many devices could send measurements to the M5 Stack?
Edit:
I'm using the Firebase Realtime Database. I'm already storing some data into the database using a normal M5 Stack, but I'm not sure whether it would work with the packets received from LoRa. I'm planning to use a LoRa temperature sensor. The message should contain the temperature measured, timestamp and battery level. The LoRa packet should be sent every 30 minutes.
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Good afternoon, so I have currently an MQTT session active. I am using Eclipse Mosquitto as a broker.
The publisher is a Core2 from M5Stack that has a connected sensor and this device sends the read temperature to Mosquitto which through Prometheus plots the information in software grafana.
So the problem here is that the Core2 sometimes runs out of battery, but grafana keeps plotting data on a loop of the last read value, which is the last value the Core2 sent before disconnecting. We have connected the core2 to the wall but we want to make sure in case it disconnects it will stop plotting data in Grafana.
Any idea on what could I do?
I'm trying to implement a simplified version of the 802.11 DCF protocol. My question, is lets say there are multiple nodes waiting to transmit, each have a backoff counter associated with them. Now at the beginning, they each only wanted to transmit one packet, but over time during their back off, more packets started to enter the queue on node 11. It is now node 11's turn to transmit, does it transmit all the packets in its queue?
Description - How I can get the number of BLE connection in iOS.
I want to restrict a user to add more BLE sensor after a particular number of BLE connection. I want to get the number of a BLE connection a device can handle.
A connection represents state, not traffic. The count of connections will be bound by either memory or the data structures used by the Bluetooth stack to manage them, both unknown. My answer is, "As many as it can and no more."
Packets represent traffic and each is handled one at a time. From this perspective, my answer is, "One."
However, if a packet cannot be processed out of the critical paths in the chip and protocol stack fast enough to begin processing the next packet, packets can be dropped. Experience has shown these critical paths in iOS are dependent on the traffic's packet size and rate. Additionally, other devices in the area not connected to your BLE stack may be flooding the radio spectrum and causing packet collisions outside the stack. I have seen BLE traffic go to hell with an excess of 20 connections and as few as one. From this perspective my answer is, "It depends."
I have a wireless sensor network deployed in a building. Each node is in a separate room. All the sensory data goes to a datastore.
The user once he/she gets to a room should be able to get the sensory data on his phone from the datastore, provided that we know in which room he/she is. GPS does not give high accurary neither infering it from the wifi signal strength. We thought of having the phone send a dummy frame through wifi that can be intercepted by the sensor node and then based on the node who gets it, or gets it first (in case many nodes intercept that frame) should give an indication to the system of what room the user is in
Wifi and Zigbee both communicate on 2.4Ghz. Is there a way I can intercept all the RF signals from the Zigbee node and entrepret the frame even if it is not a a Zigbee frame?
No, it's not possible, they use different signaling methods.
I'm building a portion of an app that will require the user to download files of varying size. Currently, I'm using Apple's Reachability code to let me know if I have a connection.
(http://developer.apple.com/library/ios/#samplecode/Reachability/Introduction/Intro.html)
While the reachability code can keep track of 'having a connection', it doesn't have an ability to let me know of a worsening connection. It would seem that I need to expand on the functionality of the Apple code to meet my requirement. Is it possible for me to measure the number or percentage of dropped packets during the data transfer? This would be helpful so I could message the user and be able to pause or stop the download.
There is no iOS API available that hooks deep into the networking stack that tells you when and why packets are dropped. It could be dropped at a router or it could be dropped locally because of a checksum error.
What kind of data is it? I assume TCP.
You might be able to infer the quality of the connection by examining the throughput rate. You can count how many bytes you receive per second.
TCP has something called congestion control and the end hosts (iOS devices) will throttle back their throughput as packets are dropped and go unacknowledged. So throughput may correlate with network quality. However, your throughput rate may vary for many reasons such as network congestion, packet shaping, QoS, etc.
iOS does not have a public API to monitor the wifi signal strength. There is a private API but your app would not be approved in the app store if you use the private API.