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3

According to the source code: const static unsigned int max_frame_payload_size = MAX_FRAME_SIZE-sizeof(RF24NetworkHeader); that would be 24 bytes. Maximum lenght of payload for NRF24L01+ is 32 bytes and the RF24NetworkHeader seem to be 8 bytes long. So you can send up to 24 bytes in one package. EDIT: Here is the stripped RF24NetworkHeader declaration ...


2

Not with WiFi, nor with Ethernet. People have managed it with Bluetooth, but only because it can create a transparent serial bridge. The bootloader only talks serial, so you have to use something that is serial to program it. The only possible way is to use another WiFi (or Ethernet) device, such as the ESP8266, to act as a serial bridge to connect the ...


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Each sensor point should send its address to the central point and this is how the central point knows the source of the message. Then after the central point receives a message, after if (radio.available()) command receive the data just once (not twice) and then use another if statement to determine which sensor has sent a message (by reading the sent ...


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It sounds (after discussion) like what you are after is actually a mesh of multiple peer to peer devices. That is, lots of devices, each one has multiple dedicated communication links each directly going to another device. If you had enough UART ports you could create individual UART links between nodes. The bets Arduinos only have a handful of those, and ...


2

This sounds, to me, like a job for CAN. It's the current de-facto standard for industrial inter-MCU cabled connections. It's used, not only in automobiles, but also to control elevators and almost all other modern industrial distributed applications. Note that CAN is designed to only support up to 30 nodes, so you would need to split your network into ...


1

For the AT+COPS command you are setting manual with long alphanumeric network name but then using the numeric network name. Try AT+COPS=1,2,"40471" REF //Manually select T-mobile as carrier using short format alphanumeric network name AT+COPS=1,0,"TMO" //Manually select T-mobile as carrier using long format alphanumeric network name AT+COPS=1,1,"T-Mobile ...


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Regarding your third point, a CAT6 cable may not work as well as you expect for power delivery depending on the topology you choose. The most common variety of CAT6 uses AWG24 wires with a resistance about 0,085 Ohm/m, so a 100 m chunk of such cable will have a resistance of about 17 Ohms. Assuming a current of 100mA, you will lose 1.7V in the cable, so if ...


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To answer your questions in turn: It is not necessary to connect to the Arduino solely for the purpose of making a GSM network connection. When the SIM900A is powered on, the Status LED will blink once every second. When the GSM connection has been established the Status LED of the SIM900A will blink every 3 seconds. Follow this guide, from Tutorial to ...


1

The scenario you are referring to - connecting one output to many devices - is called the fan-out. Yes, a GPIO pin has a limited amount of drive which limits the number of devices in the fan-out. There are two problems that are caused by excess fan-out: Excess current draw from resistive loads Excess capacitance from logic loads The former is evident ...


1

The Ariadne bootloader project enables upload over Ethernet to AVR boards with Ethernet shield.


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