how connect Base to Rover with UART telemetry


Please see below figure and page-7 of the user guide, https://www.polaris-gnss.com/Alpha_RTK_Receiver_User_Guide.pdf

The radios should only be usable for shorter distance line-of-sight usage. Several kilometers non-line-of-sight longer distance will need to use NTRIP Internet connection.

I’ve read the above Alpha User’s guide, and it mentions this “Telemetry Radio” which gives short-distance radio communication between the Rover and the Base.

But where can we get this “Telemetry Radio?” It does not seem to be in the Polaris store, and I can’t see any identifying information in the above pictures to know the brand, so I can search for it.

Where could we get this Telemetry Radio, and is there a similar Telemetry Radio which has longer range? I know the “Reach RS+” systems come with built in Telemetry Radio which can work up to 8 Km line of sight.

  • Thomas E. Jones

On https://www.aliexpress.com search for “lora” or “pixhawk radio” will turn up numerous options, with some having 8Km or 40Km range, longer distance more expensive.

Can I adapt this module bluetooth to the above configuration? In order to get RTK over radio
#Aliexpress US $2.18 10%OFF | HC-05 módulo transceptor Bluetooth HC05 2,4G RF módulo inalámbrico Industrial Bluetooth RS232/convertidor de TTL a UART 6 pines

From its description it’s not clear whether it can be used as BT transmit/receive pair. Possibly it’s short range 10 meter type, not sure could be usable for real applications.


A way to receive corrections via UART and be able to receive the NMEA Messages from the rover via bluetooth is to make a modification to the above configuration described in image. I can connect a HC-05 (bluetooth module) instead of a real time controller, but before I have to match baudrates in both Alpha+ and HC-05. I’d make a proof in rover mode only, with no corrections received. It’s was successfully.

Next step it’s to get some radio modules to test the complete configuration and the range of uses. Radio link is only preferred if no 4G/LTE,3G is available, only in such remotes areas!

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We have seen some customers using below radios. One can choose a radio that support minimum of 19200 data rate over the air for sending base data in RTCM format to the rover for the required distance range. .



Great radios, but isn’t permitted in my country the use of the 900 MHz frecuency, I have to look for 433 MHz (short range).

I did a test here with the hc 06 it works too

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Do i need to hook up the white wire Rtk nmea and the black wire, if i use Bluetooth smartphone as data collector?

Earlier shipped Alpha+ unable to use internal Bluetooth if using UART interface for radio transmission, requiring additional Bluetooth module if using phone for RTK results. So will need to connect 3rd wire NMEA out and 6th wire GND to the Bluetooth. According to Alpha User Guide, 3rd wire seems to be yellow color?

Base and rover communicating thru radio?
pls teach? me step by step procedure

You can find the instructions here:

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about the Uart telemetry were you able to get it work with external bluetooth as shown in the picture above.?

I have not tried yet, I have had a hard time finding an FTDI adapter to configure the radios (sik radios v1). Besides being more comfortable to obtain corrections via NTRIP, I have noticed that around 80% - 90% of the cases in the areas that I have been I have mobile coverage, so I have not needed much to adapt the radios

what app do you use in collecting point and stakeout?

Mobile Topographer Pro

if you happen to make it work sir, please share your blessing thank you in advance

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Não tenho conseguido um bom resultado com o Mobile topographer pro.
Alguém Sábe de algum outro aplicativo?

Fieldgenius Android or try Survey Master