The Smart Radio runs a customized version of Openwrt with enhancements related to the Doodle Labs Mesh Rider® technology. These enhancements are useful for applications requiring low-latency command-and-control transmission and high-throughput video - e.g. UAV and robotics.
The purpose of this guide is to aid a programmer in configuring the Smart Radio Serial interface. Communications over the Smart Radio’s wireless interface are IP based, so it is necessary to relay packets from the network to the serial interface. This guide includes examples for how to send data from the serial interface of one radio to that of another radio, or to simply send packets directly over the network to the serial interface. The guide is organized in the following sections:
1. Introduction
2. Hardware Setup
3. Serial Interface Configuration
4. GCS Finder
5. References
Doodle Labs currently offers four main
hardware variants in its Smart Radio lineup. UART is available on all hardware
variants. However, these hardware variants have different pinouts and you
should refer to the documentation package of your specific hardware for pinout
information. The hardware versions can be differentiated by the model number. In
all cases, the UART is implemented as one TX line, one RX line, and GND.
Please note that -
1. The legacy models, RM-****-2H-*U have a USB host port on the auxiliary connector, and have no UART port. For the UART port, you require RM-****-2H-*S model.
UART Connector
· The UART connector is a 3-pin connector consisting of TX, RX, and GND. The TX and RX wires should be coupled closely with the GND wire for good signal integrity.
· Typically when two devices are connected over UART, the TX wire of the first device should be connected to the RX wire of the other device and vice versa.
· While most models use 3.3-V TTL signalling, the External Smart Radio uses RS232 signalling. Please consult the documentation package of your hardware before hooking up the UART. Please consult the documentation package of your hardware before hooking up the UART.
If you are bridging the UART port to the Mesh Rider network, then you will also need to use the main network interface of your device. For -H, and -J hardware, this is ETH0, and for -K and -L hardware it is the USB data interface. For the remainder of the document we will use generic diagrams for the Smart Radio with one Ethernet port and one UART port.