Anyone tried Laird RM1XX modules ? part 2

(Ricardo Sousa) #106

Hi, Im trying to change my RM186 BLE from central to peripherical. After reading all the posts you guys share from your successful experiences and contacting Laird for additional information, I’m not being able to connect my j-link base from Segger to the module.

I dont have the DVK(only the module) and I’m doing it with the 19 pin connector. Also I saw that Laird did an new release on the firmware, which got to new upgrades without new information. The main problem should be the pinout connection to the module, since I only got the 19 pin connector and the j-link does all correctly except he cant connect to the module.


I’ve been programming these via SWD recently (flashing from central to peripheral). I’ve used a NRF dev kit with jlink firmware, but a segger should also work. Working with a bare RM186, you need to wire pin22 (nreset) to SWDIO, pin23 (nc) to SWCLK, pin 24 (gnd) to gnd, and pin 12 (vcc) to VTref. Segger is programming via SWD. This assumes that you are powering the RM186 via a 3.3V supply as the Segger does not provide it. I then verify connection to the device using NRF Studio, you’ll be able to see the firmware layout on the RM186 if you connected fine, after that, I flashed using the firmware tool supplied by laird rather than using NRF studio.

(Ricardo Sousa) #108

Thank you for the information. I was trying JTAG pinout on j-link. Now I changed the pinout and connected all fine, but still not able to connect/identify the RM186. Could you explain me how you are doing it with the software?



I use nRFgo Studio to verify the connection - as you see I’m using the a nordic NRF52 dev kit as my programmer and this is connected to the RM186 via SWD (P20 header connector). The NRF52 is setup with a jlink segger firmware. The photo shows the nRF51822 (the mcu on the RM186) listed and the layout of its firmware (bootloader, application and softdevice). I use this to make sure I’ve wired up my programmer correctly and that windows is able to see the device.

Next I followed the instructions included with the RM186 PE firmware - basically fire up an admin command prompt, navigate to the directory where the firmware is, and then “__LoadCombinedRM1xx_PE.bat 186_EU”.

(Ricardo Sousa) #110

Thank you so much for the help you providing. Unfortunatly I’m not being able to detect the RM186 yet, but I’m still trying to figure out why and meking sure the pinout is well connected.

(Venkatsundar) #111

How to configure laird RM186 for India’s frequency, duty cycle and other regional constrains?
I configured the laird sentrius gateway for India’s configuration using ttn forwarder. Looking for ways to communicate RM186 development kit to sentrius gateway. Please help. I’m new to lora.


There are three default channels in India to use, all the gateways should listen to the channels with 125kHz. They are 865.0625MHz, 865.4025MHz and 865.985Mhz

In India, we specified LoraWAN specified the following channels for India between 865-867MHz:

Channel Frequency(MHz)
0 865.0625
1 865.4025
2 865.985
3 866.0
4 866.2
5 866.4
6 866.6
7 866.8

The data rate that can be used in India are listed in the following table:

Data Rate Spreading Factor& Bandwidth
0 SF12 & BW125kHZ
1 SF11 & BW125kHZ
2 SF10 & BW125kHZ
3 SF9 & BW125kHZ
4 SF8 & BW125kHZ
5 SF7 & BW125kHZ
6 SF7 & BW250kHZ
7 GFSK: 50kbps

The maximum EIRP in India is 30dBm, the antenna gain dbi should be subtracted from the TX power downlink message。

The maximum allowed payload size is listed in the following table:
Data rate Payload (bytes)
0 59
1 59
2 59
3 123
4 230
5 230
6 230
7 230