Set up specific BLE devices to communicate either without pairing or with automaticly pairing

RE: Set up specific BLE devices to communicate either without pairing or with automaticly pairing

Petter Myhre — Tue, 09 Feb 2016 10:44:37 GMT

Sorry for the late reply. I have been out traveling for the last two weeks. What do you mean by uart version of multi link? The ble_app_uart_c example connects to one peripheral. So this has to be modified if you want to connect to multiple peripherals.

RE: Set up specific BLE devices to communicate either without pairing or with automaticly pairing

erltot — Fri, 22 Jan 2016 14:44:28 GMT

I cannot figure out how to set this up so I can message different peripherals from the example in the tutorial or the example you are refering to.

Edit; I see that there is a multiperipheral example in the SDK 11 package so I will check this out.

Edit2; I could not make that example, or the one you reffered to earlier to work, so now I am sort of stuck..

Edit3; So I got the multi link example with SDK10 working, with using S120 on central and S110 on the peripherals. I could connect 4 peripherals so I guess it covers my need atm, although I was not able to verify cause I only had one device with buttons. I have a small issue with uart not working in this example, and I can't quite figure out why Am I right to assume the example you created is the uart version of multi link?

RE: Set up specific BLE devices to communicate either without pairing or with automaticly pairing

Petter Myhre — Wed, 20 Jan 2016 14:41:29 GMT

The best one would be the one you are already aware of, ble_app_uart_c. This is example is made for 1 link, so you would need to modify it. In case BLE_GAP_EVT_CONNECTED in on_ble_evt() you can see that the connection handle is assigned to the m_ble_nus_c struct; m_ble_nus_c.conn_handle = p_ble_evt->evt.gap_evt.conn_handle;

RE: Set up specific BLE devices to communicate either without pairing or with automaticly pairing

erltot — Wed, 20 Jan 2016 14:17:45 GMT

Excellent. Is there any specific examples that can show me how to use the connection handle?

RE: Set up specific BLE devices to communicate either without pairing or with automaticly pairing

Petter Myhre — Wed, 20 Jan 2016 12:41:31 GMT

Sure. That works, I just thought it would be easier to have one application.

You can use one of the methods in my answer to connect to the robots. After your are connected the connections are identified with the connection handle that you get with the BLE_GAP_EVT_CONNECTED event, and this is what you use for further communication. So you can just tie the connection handle together with the device addresses. When you send a command you would know what connection handle to use if you get match on device address in your switch statement. And when you get data from a robot, you can use the connection handle to identify the which robot it comes from, because you know the device address.

Sending and receiving data over the links every 200 ms for three links shouldn't be a problem. It depends on the amount of data of course.

RE: Set up specific BLE devices to communicate either without pairing or with automaticly pairing

erltot — Tue, 19 Jan 2016 19:06:48 GMT

I (or we, we are a group) are going to have a java program on pc that will recieve measurements from- and then send instructions back to each robot, 3 or 4 of them.

Preferably I want to get away with not having to run any other software than this java program and the drivers, so I figured I could use the UART BLE example and communicate through the serial ports.

This is sort of allready solved, but we had to pair the devices first. I'd rather have the adresses for each robot in the nrf software and somehow include which instruction goes to what robot with a switch case or something similar. I have not yet figured out how to do this.

It is very important that this is concurrent, each robot is running real time schedulers on a separate mcu and will ideally return measurements, encoder information and need new instructions every 200ms..

If this is very complicated I'd love to know :)

RE: Set up specific BLE devices to communicate either without pairing or with automaticly pairing

Petter Myhre — Tue, 19 Jan 2016 15:51:58 GMT

Version 0.4.1 of the BLE driver supports SoftDevice S120, so it should be capable of having 8 peripheral connections.

RE: Set up specific BLE devices to communicate either without pairing or with automaticly pairing

Petter Myhre — Tue, 19 Jan 2016 15:50:13 GMT

I'm also not sure what kind of application you need on the PC. What kind of control are we talking about. If it is only sending simple commands maybe you could get away with using Master Control Panel, but this only supports one connection, i.e. only allows you to control one robot at the time. We are working on a new tool that will allow you to be connected to multiple peripherals, Yggdrasil, but the current version doesn't support sending any data, it only supports connection and service discovery. The best option is maybe the BLE driver for Windows, available here. It allows you to control the SoftDevice over UART. The latest release uses S130 1.0.0, so as a central it can be connected to 3 peripherals.

RE: Set up specific BLE devices to communicate either without pairing or with automaticly pairing

Petter Myhre — Tue, 19 Jan 2016 15:37:17 GMT

It does not. The S110 supports peripheral role only. The S120 supports peripheral and central role but not concurrently, and as a central it can have links to 8 peripherals at the same time. The S130 supports concurrent peripheral and central role, but the release (2.0.0-7.alpha) that has SDK support can as a central only have links to 3 peripherals at the same time. The latest release (2.0.0-8.alpha) can as a central have links to 8 peripherals at the same time. It is a bit hard to use atm., but I have made an example here.

So, you can use the same SoftDevice on both sides, but if I were you I would have a separate application for the robots. I don't see any big advantage of mixing the applications and then detecting which of them are going to be used.

RE: Set up specific BLE devices to communicate either without pairing or with automaticly pairing

erltot — Tue, 19 Jan 2016 13:37:42 GMT

Regarding peripherals and central device, does this imply that I need to use the S120 soft device for the server and S110 for the robots?

I was thinking that it would be better to have only one version with software for the nrf device, where I have some sort of function or switch/case to detect wether it is in a robot using spi, twi, or uart (pc) but this may be more complicated than i can comprehend - what is your opinion on this?

I am going through the BLE tutorials now so hopefully I will get a better grasp on how to solve it.

RE: Set up specific BLE devices to communicate either without pairing or with automaticly pairing

Petter Myhre — Tue, 19 Jan 2016 11:33:46 GMT

The robots would be peripherals and the pc would be a central device.

So you can put some information in the advertising packets that the central will recognize.

It could be the addresses of the peripherals, one or more UUIDs, one or more device names, or something else.

RE: Set up specific BLE devices to communicate either without pairing or with automaticly pairing

erltot — Tue, 19 Jan 2016 10:33:24 GMT

I have a pc that I want to use to control them all. I would like to use mesh topology in case one of the robots are out of reach from the server, and looked into the BLE mesh project from NTNU, but I know this is not trivial, so to begin with a star topology will be sufficient to begin with. It is prototyping / proof of concept

RE: Set up specific BLE devices to communicate either without pairing or with automaticly pairing

awneil — Tue, 19 Jan 2016 09:46:52 GMT

I guess the background is here:

devzone.nordicsemi.com/.../

RE: Set up specific BLE devices to communicate either without pairing or with automaticly pairing

Petter Myhre — Tue, 19 Jan 2016 09:34:37 GMT

What do you mean by link between robots? Do you want to have communcation between them? Or you want to have communcation between the robots and a controlling device? How many robots are we talking about? Is this a prototype or something that will go into production?